GM 3100,3400 Thermostat Replacement

[@ratbert86]

Did this job last night. Here's an alternative if you don't have a wrench like that: Pull the throttle body. It will give you access to that bottom bolt and allow you to use a regular combination wrench. It doesn't really save any time as you have to disconnect some hoses and sensor connectors but it does make the job possible without any special tools. Plus, you can clean the throttle plate before putting everything back together.

[@emmettturner9452]

Didn’t improve access on my 2000 Pontiac Montana. :( Too many lines around. Still had to come from below with a tiny 8mm wrench that only gives a twelfth (1/12) of a turn per flip that you will drop every flip or so since you can only manipulate it with your fingertips (made breaking the bolt loose just as difficult). The 12 point VW carb wrench he had would’ve been much appreciated since there is a 50/50 chance you will get the wrench backwards when you get it back in place. Of course, there’s a good chance you will drop it AGAIN only to get it seated after a third attempt to find that you are in the same orientation you last were and you STILL need to flip the wrench. A few more drops and you’ll be praying for a meteor to end it all when you’ve tried to seat the wrench 10 times to get one more 12th of a turn. I will NEVER start this job again without an S-Type “Obstruction Wrench,” VW Carb Wrench, GM Thermostat Wrench, or similar. The right tools are cheap and the hours of frustration to do it without them just isn’t worth it!

[@ratbert86]

@@emmettturner9452 Sorry it didnt help for you. I have blocked most of the repairs I had to do to that thing out of my mind since I got rid of that van.

[@ryans413]

If you have a Pontiac Grand Am or Chevy Malibu removing the throttle which is only a couple more steps really helps make more room and will actually save you time fighting with getting the bolts off. Plus a bonus you can clean the throttle which is always a plus

[@DeadkingAZ]

Works on the rendevous 3400. Good tip.

[@spencerbeales8965]

Good tip, saved time absolutely. I watched another video where a guy pulled the exhaust. Are you kidding.? In

[@countrypete]

DUDE! THANK YOU! I have a neighbor who needed this done and she asked me to help her out. Being a man I of course said "you betcha." I opened the hood of the car and thought "no way!" I went to my computer and goggled and up popped your vid. I honestly would not have even tried without your showing how it was done. Thanks again!

[@billo66109]

Thanks for the video! I changed the thermostat yesterday on my 2002 Impala 3.4L. The bottom bolt sucks. Even with the "slotted" housing, I couldn't pull the housing out with the bottom bolt partially in due to interference from the coolant pipe, throttle, and heat shield. Some things to gather up for anyone considering this: various 10mm&13mm sockets & extenders. A curved or stubby 13mm wrench. Liquid wrench. Telescoping mirror to see things. Spring clamp pliers. PATIENCE. Thanks again!

[@spelunkerd]

That rag idea is gold, Rich. Often the key point is a 'beside the point' comment that one can take away later.

[@doublej4077]

At 2:51 in the vid when you pull the thermostat housing off it looks like the bolt hole is open in a way that you do not need to unscrew that bottom bolt all the way out . I think you could just leave it on and still pull the housing off .

[@mustardflavor]

After watching this vid today, I decided that I could pull this off. However, I do wish I would've read all the comments and realized that the bottom bolt didn't have to be taken all the way off to remove the housing. The job took me 4 hours. That bottom bolt is a PAIN! I tried removing the crossover pipe but didn't have any luck. Anyway, thanks for the vid! my hands are sore now, lol.

[@bakdraft6578]

The slot on the thermo house is meant to loosen the bottom bolt and slide it off w/o removing the bolt.

[@garrettb72]

Yeah to bad theres a thermostat in there.....

[@SixtyNinersclub]

With the thermostat in there you can't slide it off. Tried for hours so you have to remove that bottom bolt

[@deyevoleg]

I am Russian guy, and your direction helped me to replace thermostat on my Chevy Malibu by myself! Thanks a lot!

[@WAYMOBB]

Never thought peter griffin would explain how to replace a t-stat

[@fjfairchild73]

Shut up, Meg

[@sammyanderson2726]

Lol im dying over here 😂😂😂. I love the response " shut up meg" lmfao

[@sammyanderson2726]

I have literally went back and read this like 5 times and laughed every time 😂😂😂😂😂

[@williambrucesanders6878]

Dude u really messed this up for me . Lol I thought I was in Boston the whole time. Now I gotta watch someone else ur funny af

[@Daddyduckway]

🤣🤣

[@Catfishchristian]

Thanks man. This video allowed me to fix it myself instead of asking for help

[@RichpinTv]

Great to hear!

[@JackieTheTruck]

One of the best how-to mechanic videos I've seen. You do a great job of explaining exactly how to get at that difficult bolt, real good job! I'm sure I'll be checking more of your vids out in the future as I work on different vehicles. Keep up the good work! : )

[@prescottproperty]

I am a novice mechanic. I used this video to replace the thermostat in a 1996 Buick Regal with a 3100 engine. This video is right on the money! The one issue that I ran into was that I couldn't break the bottom bolt free. So, I had to get the wrench on the bolthead from the front of the car while my cousin held the wrench on the bolthead with a bar. The bolt quickly broke free from this position. Also, I had to bleed my system of air. The bleeder screws worked perfectly. I now have great heat!

[@timt4575]

This job took me 8 hours on my 04 Monte Carlo 3.4L without taking off the exhaust crossover or heat shield. Most of the time was trying to get both bolts back in with such little room. FWIW, I purchased the Calvin GM Thermostat tool but that did not have enough clearance to be of use. I was able to get the bottom bolt with ease using a standard flex head ratcheting 13mm wrench. I was able to fish my hand around behind the brake fluid reservoir and underneath the crossover pipe. What a pain GM!

[@HardWhereHero]

Whats a flex?

[@daviedrussell1421]

Read all of the comment

[@AXMRDRA]

Tim T I'm about to do this to my 04 monte carlo 3.4 any other advice?

[@thomasmaddox1733]

I'm a CDJR tech and I have to say bud you make a really good How-To video! It gives me some good ideas for how to make a few myself on the CDJR line ups, so THANKS

[@hoggerharleyrider7043]

Really good job on the video. I came to the same conclusion on the bottom bolt, the housing won't slide over the thermostat unless the bolt is removed. I did find it gave me more room after removing the heater tube from the water pump, removing the hoses and lifting it up out of the way. The bleeder bolts usually aren't corroded up because they are brass and in antifreeze so no problems there and you always need to bleed the system. Thanks for the help richpin!

[@dwaynemadsen964]

"The smaller hands you have, the better" LOL! The story of my life! Thank you for the tip on using a screwdriver for leverage, and how you leaned on the fender and used your left hand. These "Mechanics Yoga" tips are priceless.

[@jeffreycoogan4616]

Thanks so much. I managed to change my thermostat about 8 years ago. Now I need to do it again and I couldn't remember how I did it the first time! They really put it in an inaccessible place. Thanks for the refresher!

[@motoozark4361]

I just did this job and it can be done much easier then all of the youtube videos I've seen showing you how to do it. You will need a 13mm VW carb wrench which can be bought on ebay. You don't need to remove anything accept the air box duct and lid Once thats all out of the way go under the crossover pipe with the vw wrench and get it on the bottom housing bolt, it helps to have a flat head screw driver above the crossover helping get the wrench on the bolt. Once that bolt is broke loose, your your index finder on your right arm still reached under the crossover bar and the flat head coming in from the top to back the bolt out. Go ahead and take it out and use a socket to remove the top bolt. Remove the housing and bad thermostat. Apply a thin line of silicone around the rubber gasket on the new thermostat on the side that faces in the engine and position is in there. let it cure for 24 hours. Now prior to putting the housing back on, put the bottom bolt back in barely screwed in at all, by about one thread. Remove the two bolts on the on the heat shield at the front of the engine, you dont have to remove the heat shield removing these bolts will free it up enough to get the thermostat housing past it and the thermostat and onto the bottom bolt that is barely started into the block. You may need to use the flathead to help push the shield out of the way as you work the housing on. You'll have to come in from the top and it might take a couple of tries but its doable. Be careful not to knock the thermostat loose or you'll have to re-silicone it and wait another day, it should be pretty sturdy though if the silicone cured all the way. Once you got the thermostat on the bottom bolt, go ahead and start the top bolt to keep it in place then put the bottom bolt in the same way you took it out, right hand index finger on the bottom and flathead screwdriver on the top, then tighten with carb wrench.

[@marshallrosenberg709]

Great video and you had really good control with the camera while you were doing it and explaining it. Also, great tips as well. Mine is stuck closed and I have to change it as it looks like a pain in the ass but going step by step and being patient, the job gets done. Thanks for your video!

[@navbuoy]

I normally take my time - the exhaust is in the way but the bolts look rough and I didn't want to touch them. So I took off the hose off the fuel rail and removed the sensor above it from the throttle body giving my enough room to get my wrench in and loosen that infernal second bolt. Great Vid by the way - thanks for posting!

[@butchbelanger1012]

Rich, Finally got one to install correctly. Initially I bought a stant superstat. After comparing it to the one being replaced noticed that the upper part of the cone was a bit taller than the original. Replaced the superstat with an original stant which had roughly a 1/8" smaller cone.

[@4Mary6]

I also wish to join the chorus of thanks. This video was just the information I needed. I didn't have the curved wrench that you have. After looking around the internet I found a specialty wrench on eBay called a Cal Van 751 GM Thermostat Wrench. It is a U shaped wrench that fits under the exhaust manifold to get that lower bolt. I had to place a piece of wood on top of the transmission block to hold this wrench in position. I also had to use a 8" cheater pipe to get enough leverage to finally get the lower bolt to loosen up. After that, it was just as you showed. Thanks again!

[@zenmonk3]

I love how thorough you describe the steps an warnings of how not to loose the frigan bolt , awesome job I appreciate you and your help :)

[@daveshannon6027]

Thank you SO much. very well done video. The towels were a good idea to catch falling tools, bolts,etc. But I ended up using a hard-access, curved 11mm/13mm double box-end wrench and tieing a string to the 11mm end, attached the other end of the string to the carb. so I could easily fish out the dropped wrench - which I did MANY times. This allowed me to dispense with the towels. I also backed out the bottom bolt just enough to clear the thermostat so there was no need to restart the bolt (so glad I did that) ... After 4-1/2 hours, half of which were filled with cursing, I got the job done for $15 instead of $400. Great excuse for a warm down in the hot-tub licking my wounds after prolonged torture. Your hands must be miniscule!

[@jimr8198]

You did the right thing by just backing out the bottom bolt enough to clear the thermostat. The housing hole in the bottom is designed with a slot so you don't need to take the bolt out.

[@JasonKale]

I tried to leave the rear bolt in and can start it from the front as it seemed youre suppose to slide the aluminum piece in but there is just not enough room to leave the rear bolt in and and get the aluminum tube back in over the thermostat...tomorrow im going to try lay on top of the engine..I too spent like 4 hours...everything cam out nicely but I could not get the lower rear bolt in no matter what

[@Datwhit]

Nice video. One thing I noticed is that the thermostat housing lower bolt hole is notched. All that would be needed is to loosen the the lower bolt and remove upper bolt to get it out saving some time from taking it all the way out.. If its the factory housing it looks like GM already knew how bad it would be to get at the bolt and made it that way to help. Keep the videos coming!

[@TheReaganite]

just want to say thanks for this video. helped a lot. however I was able to get the housing off and back on without removing that bottom bolt. I did remove the throttle body. made job easier

[@jimmcdowell6000]

I had to replace my thermostat today. I followed your advice except I removed the throttle body and the coolant pipe. The bottom bolt was still tough. I used a shorty wrench with a screw driver to hold it in place. It worked. Thanks for the video.

[@AlwaysHopeful87]

Ouch!

[@HOYS]

Rich: I'd like to point out that these engines are referred to as 3100's and 3400's. The 3.4L GM engine that was referred to as 3.4 was a DOHC engine. This procedure will be different for the different body styles that this engine is in. The W-Body car you did this in is harder than other platforms like the N-Bodies. The bottom bolt on the housing does not need to be removed, just loosened. The housing is slotted on the bottom bolt. This can make the job much easier. Great vid!

[@mpfaith20]

Great video! I can't thank you enough! I have an '02 Alero 3.4L so it was a little different. Not an easy job but MUCH easier after watching you. The guy at Autozone said the instructions he had in his computer system said that you need to take the exhaust manifold off. I can see how that would make it easier but after looking at those bolts, I didn't want to take the chance of breaking half of them off. My son is taking his driver's test this Friday and they won't let you take the test with the "Service Engine Soon" light on. Thanks to your help the light is off and we're good to go!

[@RichpinTv]

I am glad your light is out that is good news.

[@patcallahan1050]

I just looked at Autozone's self service pictures, and they showed pictures of the 3.1 MPFI - yeah, the old 2.8/3.1 design! I looked for my brother's 97 Monte and I know it has the 3100 and is not the same! Autozone is about as worthless as they get!

[@ernieschroeder]

I did everything as you showed, except used a ratcheting wrench on the bottom bolt. It worked well. The whole job from opening the hood to finish around 35 minutes.

[@lothdragoon]

I know this is old but thanks for the video it helped me alot. Also, i've found it easier if you remove the throttle body first before removing the thermostat housing. Made the job a WHOLE lot easier and I didnt have to buy that special tool. Once the throttle body was out of the way, I was able to use a 13mm wrench to remove the 2 bolts to the thermostat housing. For those wanting to know where the throttle body is, at 2:17 is part of the throttle body at the top of the screen. The throttle body is secured by 2 13mm bolts.

[@RichpinTv]

lothdragoon The only reason i and others out there did not remove the throttle body is the extra work involved and a new gasket other than that it would indeed make the job easier.

[@wederingas]

Thanks Rich, my wife just bought an '05 Buick Rendezvous with a 3400 engine and she does all the work herself, and the thermostat needs changing

[@RichpinTv]

Good to know that there is a problem with the superstat....glad you got it fixed.

[@SaturnMan2012]

yep, that's what I normally do when i get those answers from you and the other great mechanics on here. Thanks though Rich, Your always a huge help. Even when you don't have all the answers you still the best. Thanks.

[@auntester7760]

Thank you for the video. Ordered one of the below wrenches listed at Amazon listed below. Also went ahead and bought a set of the crescent shaped wrenches like the one you used at Harbor Freight today for about $18. Hope to tackle this job before summer. Thanks again

[@philmerrow174]

Thank you for this video. I used it to replace the thermostat on my daghter's Lumina. It was 100% on. That lower bolt is a pain in the rear end. Thanks again.

[@drpatelnd10]

I rarely comment on anything...However, great video! I believe that the 3.4 is a royal PITA. That second bolt on the thermostat housing is just ridiculous. Anytime I work on this car I wish that GM actually went out of business. The major reasons their products suck are the fact that most people cannot / will not pay for simple maintenance procedures due to the cost for labor. Then there is premature wear and the whole vehicle heads to the junk heap.

[@larrywilson1786]

I loosened the heat shield from the exhaust, then put a very short 13 mm socket onto the bottoe bolt. It's very tight fit but it will go on. For the socket, use one that will allow you to use a open ended wrench on the end. Do this just enough to loosen the bolt and take the socket back off before finger loosening the bolt or else you will pich your socket in between the exhaust and the thermostat housing.

[@David.-_-]

Larry Wilson the real mvp here folks. thank you!

[@DrivewayMOB]

Yes this was better than the video lol. Thank you sir.

[@ScottMcGillivraySnaplink]

Thanks for the video. I went out and bought a flex head ratcheting box end wrench at Lowes for about $22.00 and it was well worth it. 13mm is 1/2", so I put a 1/2" rachet into the open end of the box end wrench for leverage on the bottom bolt. On the top, I used a universal on a wobble head extension. It worked great. Unfortunately, I dropped the top bolt and now it has disappeared. I guess I will go shopping tomorrow.

[@johnpritchett156]

As a former NAPA parts guy, I can offer some major advice before even installing the new thermostat. This is a game changer and can help you save damaging your own car and whatever else is in the general area as well (you are welcome lol). First thing is to "pop" the thermostat open gently by opening the center with both of your fingers/thumbs to make sure it won't stick initially closed since they sometimes do that (more than a few mechanics told me about this) and can cause your engine to overheat- and one more overheating might just be the one that warps that head! Be sure to check the thermostat by boiling water in a small pan and put the new thermostat in the pan to observe it open properly, that way you know it actually works and not partially or not at all since sometimes they are shipped with "issues" as I've seen them come right from the factory not opening properly. You can either leave it in the pan to cool down and watch it close properly or take it out with a pair of tongs or a fork etc. making sure not to jam something into the part that closes in the thermostat. I personally have found 2 "brand new" thermostats that wouldn't open up right and was able to work the part open & closed to get them to work right since they apparently were misaligned from the factory, but couldn't see it right away- was on new Honda thermostats as NAPA used to get their Honda replacement ones from Honda back in the 90's. I can say that the 1996 3.1 Monte Carlo engine is the SAME setup as the above, so yup you have a nightmare of a time changing the thermostat from 1995 to 2003 that I know of sadly... I almost want to look for one of those thermostat housings that are mid-hose (like some of the Olds & Buicks from the 90's) that just drop-in the thermostat- but not sure of the exact year & model cars to check lol!

[@hugh3rdof5]

excellent advice. Alas, Two years ago, I replaced a thermostat on a Montana van. Used a thermostat with a "lifetime" warranty -- bought at AAP. Part for the course there, the T-stat apparently has been sticking for over a year..... and I kept thinking, through all the trying everything else that, no, it can't be the T-stat, I just changed that..... grrrr..... (til I got to the point that I'd ruled out everything else.....) This time, I bought an ac/delco . Yet even with this one, tested it first.

[@ryans413]

Just boil a pot of hot water then throw the thermostat in and watch if it opens. It’ll open when hot close when cold. If it opens take it out of the hot water and wait to see if it closes if it dose your good to install it.

[@ronhartwell4725]

I would not have known what to without your video and instructions thank you

[@RichpinTv]

I am with you 100% i can not understand why the slot is there but does not help one little bit.

[@criticalfilth1421]

Great video and very informative. I only have one hint. If you noticed when he removed the thermostat housing the spot for the bottom bolt was a SLOT and not a HOLE. This makes it unnecessary to completely remove the bottom bolt. You only should have to loosen it a couple of turns. Lighten up on GM, they're working with you... a little.

[@ryker4124]

Bottom bolt does not need to come out. Just loosen and the housing will slide off because the lower hole is slotted.

[@HUBBABUBBADOOPYDOOP]

Hey, Rich- THANKS for the video! BTW- next time- it'd be more informative to actually show the placement of the new thermostat, and to make a visual and a verbal note of how to position it correctly in the bore- so that the air bleed hole is facing upward at 12 o'clock. Everyone here might not be aware of this important procedure.

[@phoxphase]

Thank you for taking the time to post this very helpfull video

[@hugh3rdof5]

Hi Rich.... Am having to do this job for the second time on a 2000 Montana. Always appreciate your videos and your creative tips. Thanks to 13mm ratcheting wrenches, I managed to get off both both bolts this time, surprisingly easily. BUT (keeping me humble), once again, I'm unable to get the thermostat housing off, without more serious "surgery" on the patient. I'm rather amazed by your demonstration (at minute 2:45) that once you get the housing bolts off, it's then easy to slide the housing off. If only. Maybe for other GM vehicles, yet for the Montana/Venture, that exhaust wrap around seems too tightly situated on top of the thermostat housing -- preventing me from simply sliding it off. (the thermostat underneath makes it impossible to remove, or for that matter put a new one in) Like the last time, I suspect I'm going to have to take off the throttle body and the coolant bypass pipe.... (and even then, I wonder...)

[@emmettturner9452]

Same problem, same 2000 Montana. No way to slide it on/off with a thermostat protruding into the housing. Backing out the bolt enough to get the housing off is almost pointless since you have to back it out almost all the way. It took hours of fumbling with the open end of my 13mm ratcheting wrench to get it one tiny fraction of a turn at a time. The domed shape of the housing is too close for the ratcheting end of the wrench to fit over the bolt head. Mine is the Quinn ratcheting wrench from the 428 piece Master Technician tool set. It doesn’t look much bigger than the smallest of the big brands so I don’t think GearWrench (the brand that invented ratcheting wrenches) or anything more respected would’ve made a difference for me. :(

[@dextwo]

Great video. Wish it were up two weeks earlier when I did mine. Sure was tough getting the outlet off. After struggling with that bottom bolt, I ended up taking off the TB and it made a huge difference. My next purchase will be a set of GearWrenches, since I used the open end of my combination and it took forever. I don't understand why the OEM manual suggests taking off the crossover, I think that would be inviting trouble. Anyway, well done.

[@terrylamasters]

Thank you for your video. My friend is a mechanic and he told me how to change the thermostat. After looking in the engine compartment, I realized that I was intimidated. After watching your video it helped me to understand I can do it and how easy it was...except for the bottom bolt. Thanks again for your video since I am a Buick Rendezvous owner.

[@JerryPerkinsfitand50online]

Thanks! Could not have done it without this video. Others want you to take the throttle body off and I really didn't want to do that. Took lot's of prayers too! A couple things I noticed, the angle is higher than I though it would be. And I couldn't do the left handed thing. Went underneath the exhaust manifold like you did with the left but I did the right hand balanced the bolt on my finger tips. Stuck a screw driver in from the top with my left to put pressure in on the bolt, (had the top bolt in finger tight like he said), reached out with my left pinkie and wiggled the neck of the pipe around until I felt the bolt drop into the hole. Then with the screw driver still pressing in, I started spinning it with my right fingertips. Got enough threads in to keep it from falling out and put the open end wrench on it. Also, I could not find a Volkswagen carburetor wrench so I cut a couple inches off my 13 mm open end and used that.

[@ChUcKsDeZzY]

Yea i just did one the other day and i found it not to be so bad! took me about 25 30 mins to do the whole job!

[@Kiddro22]

Yeah I noticed that also. Now I have better confidence in doing the job now. Just completely loosen and take out the top bolt but just loosen the bottom one till u can slide the housing out. Sweet!

[@SciHeartJourney]

I have a 2002 Pontiac Grand Prix with the 3100 engine. I tried following these instructions, except for the bent wrench; a regular wrench works too. But you can only get 1/12th of a turn at a time. I did't see how a bent wrench could help. I spent the better part of an hour in the sun taking this bolt partially out. It would not slide out! Initially I avoided taking off the Throttle Body, but when I did suddenly everything became so much easier. The job was done in 15 minutes after that. So TAKE OUT that throttle body if you think it's in the way. Don't forget to get that gasket when you buy a thermostat. Luckily I didn't have to take out the exhaust manifold; that would have been a total pain!

[@aaroncarpenter759]

Yeah if you remove the throttle body, might as well clean it and put a new throttle body gasket on. Also, did you need a separate thermostat gasket or just the rubber seal that is already around it?

[@rogermcdaniel7303]

Great video, REALLY appreciate the "rag" tip! Bad enough when you loose a bolt and it falls through into gravel, but a magnet will retrieve it pretty quick. WORSE when it falls into some crevice of the engine and you can't see or get to it! Thanks much! Maranatha

[@_-Brandon-_]

3.4L grand am is a little different but close to the same...anyways the video definitely helped...i was told i would've had to take the throttle unit off itself but i guess the boot was enough...that bottom bolt was a SOB...but i got the job done...thanks..!

[@sranjesuper]

i'm a mechanic i just did this job 2 days ago on a 3.4 montana, i removed the throttle body and was able to access both bolts with a small 13 mm wrench

[@ishtech101]

did you gain access to both bolts from the top or bottom? did you remove the exh crossover pipe? It sucks to change a damn stat like this.

[@sranjesuper]

Samuel Ishmael i did not remove the crossover pipe.. i removed throttle body and was able to see both bolts from the top. You can't access the thermostat from the bottom anyways. I'm pretty sure it's faster this way than removing crossover pipe anyways. Disconnect all the connectors and pcv hose near the throttle body and move everything away

[@RichpinTv]

Samuel Ishmael I accessed the bolts from the top and the pipe stayed in place.

[@ishtech101]

richpin06a Damn, still looks tough, but thanks for the advice.

[@sranjesuper]

lol i did my 2nd one today on another montana... this time it took me 45 minutes in and out including the coolant temp sensor next to it.

[@JSBautomotive]

Buddy you are speaking my language, I was gonna do it a similar way but thought I'd check the tube before i dive in. I'm gonna try my best to use a 13mm 1/4" drive wobble socket to get that bottom bolt. Great video fren. Thanking you

[@RichpinTv]

Hope it works for you.

[@metomjr]

Excellent video. I was exteremely frustrated when I changed the themostat and there was no change to my overheating problem. Then I remembered to bleed the radiator...it gurgled for a bit and the temperature was finally stable! I did have to remove the bottom bolt...it was impossible to get the housing back on with it in place. Hopefully I can get a few more miles out of my 2003 chevy impala (197,000)

[@birdwing98]

I own '95 Buick Century. On this engine, it is not necessary to completely remove the lower T-stat bolt. Just loosen it. There is a notch cut in the housing, so it can slide forward without removing the bolt.

[@RichpinTv]

If it has a jiggle valve that goes up but the ones i replaced did not.Did you compare the new to the old one to make sure it was the right one before installing.

[@jasoncamps77]

Thanks for this video. I have no idea how you're getting your hands in some of those places, as I've struggled a great deal to get that lower housing bolt off, but I finally did it. I also had the thermostat stuck in the housing which delayed me a bit. Regardless, not having to remove the exhaust manifold cross-over pipe saves a lot of time and hassle. I also appreciate the tip about the s-shaped wrench. I had to go buy one but that did help. Now lets hope I actually fixed the correct thing!

[@JasonKale]

I have no idea how he was getting his hands in those places the under the manifold trick helped me get the lower rear bolt off...Every thing came off in a matter of minutes but several hours later no matter what I tried I can not get the lower bolt back in...tomorrow im going to try to lay on top of the engine..

[@mymkii406]

Great video! I struggled with that 2nd bolt on the thermostat, even dropped it 3 times. Thank God for a magnetic telescoping wand to retrieve it. I wish I had a curved box wrench like you used it would have made it easier to do.

[@Newcumpas1]

Thanks for the help on this project, I found that I just took the air cleaner tube and the throttle body off and I could get to the bolts. The top one needs to come out, but the bottom one does not. You can just loosen the bottom bolt and the housing will slip off of it. Take Care

[@ryans413]

What I did on my Pontiac with the 3.4 is I took off the throttle which ain’t too hard. Just unplug all the sensor wires around the air box and throttle remove the breather hose loosen the clamps and remove the air intake hose and air filter box. Now unclamp the clamps on the two hoses going to the throttle and let the coolant drain. Now unbolt the throttle leave the cables in place just put the whole unit up and away. Now you can unbolt the thermostat hosing. It’s a couple more steps but I just find it more easy then trying to fight with the bolts for 20 to 30 minutes sometimes longer.

[@210BAMF]

Could not get the lower thermostat bolt loose, so i had to put everything back together to try again tomroow due to the sun going down. I am using a pretty small short 13 mm wrench, Could only wrap my fingers around it and use finger strengh. Soaked in liquid wrench and still could not get it started. What type of wrench do you suggest?

[@RichpinTv]

It is very easy to bleed the air on the 3100 because they put a bleeder in the thermal bypass pipe.I have a video on replacing the pipe if you are not sure of it's location.

[@Kokisslc]

The bottom bolt is very hard to remove, replace the thermostat and the temperature sensor of my 2003 Montana take me all day, thanks per the video and comments was very helpful

[@nikolarogen1393]

Glad i watched this, i started working on a friends 3.4 and ran out of daylight. I was worried i might have to take the coolant pipe out but i might be able to get in there if i move the airbox... Haha "all i removed was the intake tube". Also great idea putting the rag in there to catch bolts, i will start at it in the morning again

[@joelscharfenberg4557]

Good job sir... Good camera angles and descriptions... Thanks

[@valerie9007]

Thanks for the video. The bottom bolt does not have to be removed, only loosened. The housing is slotted for removal.

[@RichpinTv]

In my case loosening the bolt would not let me remove the housing but it should be attempted first.

[@ikemen1]

Also In my case loosening the bolt would not let me remove the housing

[@foxdmulder]

As I always say, you dont have to be a contorsionist to be a tech, but it does help.

[@deke909]

Hey,I also use a short 13mm wrench but I use a second box end to hook onto open end of the small wrench.Setting them up will take a little persuading.

[@jeremyoros4121]

good video.. i was frustrated with that bottom bolt.. now I know how to get on it, thanks!

[@damon9408]

The bottom bolt is delicate surgery. I used a long hemostat to hold the bolt, while gently starting it. Try it. it works. Take your time.

[@butchbelanger1012]

After trying numerous times in replacing the housing. I noticed that the new thermostat I bought which was a stant superstat was noticeably taller (the cone) than the original one. I swapped this superstat with a standard stant thermostat which was shorter and was able to finally get the housing back on. It took a few tries, but I was able to clear the thermostat and get it back on. I removed both bolts when removing the housing.

[@RichpinTv]

Yes we do realize that there is a slot in the housing for the bottom bolt but as hard as we try on some cars we can not get the housing out.

[@RichpinTv]

I have not done a head gasket on this engine.If you go down to your local library you should find a repair book that will help you out.

[@killman1971]

The coolant air bleeder screws usually can be replaced with no problem using a 10mm wrench and pipe sealant. The big problem is that the auto parts stores will not sell you one even though they carry shelves full of other Dorman products. $7 @ rockauto. Note that you must bleed the air from the water pump housing or you will have heater core problems and even engine overheating problems. Follow the procedure in the manual.

[@Newcumpas1]

There is a special wrench for this that is not to expensive, it makes the job so much easier. Also, the bottom bolt does not need to come out all the way, there is a notch in the housing that slips over it for easy removal and instillation.

[@RichpinTv]

Yes the Cal Van 751 wrench is one of them

[@bigwes1976]

Thanks for the vid Rich, I was able to change out my thermostat (2x actually) on my 2003 Rendezvous from watching your video. It was a pain in the ass though.

[@dazedconfuzed6]

i could not agree more, i watched this vid about 3 months ago trying to do the thermostat. it got done, if i remember correctly it took like 3 hours. i eventually just took stuff off till i could get to it. Now im watching videos again trying to find a way to access o2 sensor. which of course is just out of reach and blocked by about 5 different things.

[@elkompaveto]

You dont have to take the bottom bolt out. Just get it loose. The thermostat housing has an oppening for that bottom bolt.

[@RichpinTv]

I think some have more clearance than others as i could not remove the housing on this one without first removing the bolt.

[@jonathanzollman4585]

richpin06a I no this is a old video but I think my thermostat is bad now an i have a 99 Monte Carlo and it's a 3100 v6 and I was just wondering if it would be in the same place as it is in the video

[@kaserrex9509]

Alberto Barragan if you don't remove the bolt it will not clear the thermostat. just did one today.

[@RichpinTv]

@Datwhit That is what i though with the slot in the housing but with the bolt out to the end of it's threads the hosing still would not come out.

[@RichpinTv]

@suburbanator91 If you take off the crossover pipe...yes the bottom bolt would be very easy to get to.

[@RichpinTv]

It should would have helped because trying to put that bottom bolt in with the housing in place is frustrating.Were did you remove the material.

[@barrybleam8685]

doing a themostat on a 3100 is abitch did one today and guy in video was working on a 3400 witch gives a little more room at the exhaust pipe to remove the housing on the 3100 you have take the sheid off toget the bottom bolt and yes you have to take it all the way out

[@LuisGarcia-ui4og]

hey guys, i just replaced my T. Today, the bottom bolt does not need to be removed all the way, i did id but u need small hands, if you don't, don't even try it,, it took me almost 5 hours, easier said than done, but definetely doable. i have a buick 3.1L saved me 150. 00

[@theryanwitski]

Thanks for the walk through. It was a life saver

[@RichpinTv]

I have not cleaned a throttle body on the 3100,3400 so i am not sure if it is the same as the saturn.

[@sallewellyn0]

For anyone curious, this DOES NOT work for a Pontiac Aztek 2001, same engine, but there's a damn intake line in the way that blocks everything up...take my word for it...

[@RichpinTv]

Thank you for letting everyone know that.

[@TaskSwitcherify]

Incredibly impressive and educational video for the year 2000, when everybody else was filming their cats and other stupid stuff!

[@RichpinTv]

Sounds like you are bleeding from the bleed screw on the bypass pipe which is correct.There should be coolant that comes out of there in short order on a running engine.When the engine is up to normal operating temp are the bottom and top radiator hoses hot.

[@billo66109]

@DylanAEnglish You can use a regular 13mm wrench. There isn't much clearance, so you will be moving it a fraction of a turn each "flip" of the wrench. Not a fast process getting it all the way out. Let some liquid wrench soak if you can't get it started. I used a small piece of pipe that I jammed the wrench into for a cheater bar to loosen it. Get in there with the wrench you do have and check your clearances...then go out and buy additional 13mm wrenches if needed.

[@RichpinTv]

Are you getting hot air out the vents....if not the place to start is to check the heater hoses were they go through the firewall.Both should be hot when the car is up to temperature.

[@barbiegifford925]

I found that if you remove the throttle body it make it a LOT easier to get to the bottom bolt and it also give you the opportunity to clean the EGR port in the intake while you are in there.

[@RichpinTv]

Removing the throttle body would differently make things easier.

[@SaturnMan2012]

OK, people are also suggesting the AC Delco double platinum plugs. Thanks !!!!! Going to the bone yard today to get that actuator that's making the rapid clicking sound. Then I just need to figure out why my parking break does not work at all.

[@michael88h]

Raymond has a good career as a mechanic.

[@RichpinTv]

@foxdmulder You have be very flexible on this job for sure.

[@RichpinTv]

I have not removed the heating duct work on the impalas.In a case like this what i would do is go to the local u pic it yard and spend a couple of hours learning how to remove them there.

[@RichpinTv]

I am not sure how many videos i have on the impala but i do have them.I have stalling of the videos from time to time myself.