2003 Pontiac 3.4 liter Aztec Thermostat Replacement - rear bolt removal

[@emmettturner9452]

My ratcheting wrench simply didn’t fit between the bolt head and the dome shape on the thermostat housing. I had to do it the hard way, backing it out one tiny fraction of a turn at a time while flipping the open end of a box wrench using fingertips. Breaking it loose when you can barely get a wrench in there with fingertips was no small feat! Even after half an hour of gradually loosening it I still couldn’t unthread by hand. I expected my ratcheting wrench to be lower profile than one with a reversing switch like yours… mine only ratchets one way so you have to flip the wrench over to reverse. Rather than shopping for a lower profile set I think I’ll just buy a set of those S-shaped wrenches to get me out of similar binds in the future. Good tip on threading a clean bolt through first to clear the threads. Wish I had thought of that so that I could at least tighten by hand! To get it to start threading I tightened the top bolt first then backed it out just enough to let me wiggle while trying to seat the lower bolt. As for gaskets, well, I bought a replacement thermostat housing with my thermostat and it came with a large round O-ring that doesn’t seem to fit anywhere on my engine or thermostat housing. It’s slightly larger diameter than the gasket on the thermostat itself so I’m guessing later models had a groove for this (2000 Montana here). Before starting the job I looked for a gasket and saw that Rock Auto sells the same O-ring separately as a thermostat gasket. This confirmed for me that I had what I needed only to find out mid-job that I needed liquid gasket I didn’t have on hand. Doh! Well, there was no gasket before and I didn’t have a leak so I went ahead and reinstalled it without one and haven’t seen a leak since. My guess is that the gasket built into the thermostat is supposed to seal all the way around but they couldn’t count on that precision later on and made a groove for the larger O-ring. Anyone ever find one with this O-ring to confirm?

[@josevillagrana5414]

Ty for posting this video I was stuck where I was so post to take of the manafo cover until I seen your video ty again

[@SixtyNinersclub]

Awesome video man!! Gotta do mine tomorrow and not looking forward to it. Got to get it done even if it takes all day which I am prepared for.

[@SixtyNinersclub]

Update: Took me 2 days!! Pain in the ASS!! I also replaced the coolant temp sensor, recommend as well.

[@darienhenderson4498]

I want to thank you for taking the time. So my experience was that I left the back bolt barely threaded in the hole and took the forward motor mount off. I don’t think there is any easier way that back bolt is something. Removing the motor mount allowed me to reinstall the turbo over the new thermostat. Thanks again!

[@DavidTGould]

tough job... glad you got it done.

[@aldahirjaoa7061]

No se compliquen amigos. This truck by itself it is very hard to performs maintenance, so, for this thermostat replacement, I recommend remove the exhaust cross pipe (the one joins the front and rear exhaust manifold) and after that, it´s very easy, safe and efficient the replacement. Tip: apply penetrating fluid in the exhaust cross pipe nuts and bolts mininum half a day before. That will avoid or reduce the probability you broke any of them when unscrewing. Saludos desde México.

[@JasonfromMinnesota]

Thank you for your toils I am in MICH and it’s cold out side need to replace thermostat

[@st-fi9gw]

Excellent video!!

[@brendaanolco5354]

can you tell me what is the egr valve in that car

[@DavidTGould]

try this video... kzbin.info/www/bejne/poS7ZmiPntughNk Be Blessed! DTG

[@realdaxfan5233]

The black hose that you broke in the video... Do you know what it is called? I have the exact same car and the hose on mine that you broke doesn't connect at the other end on top of the manifold it is very loose and I can't seem to find a connector for it.

[@DavidTGould]

I tried Googling "2003 pontiac aztek vacuum hose diagram" looks like answer is in there somewhere!

[@joeorlando94]

Ha. I have a 2000 Oldsmobile Silhouette. Same thing. I have that tube connected at the air intake boot, but it's not attached on the other end. The other end is buried behind back side of the engine/intake manifold, and I've given up trying to find where it attaches.

[@Cr1msonFir3]

Thank you so much. The instructions at work say to take the exhaust off. Hoping this will work for me as well.

[@DavidTGould]

There a number of other viewers with great ideas (none of them suggest cutting off exhaust... that sounds like trouble with frozen studs) Patience and nimble fingers helps. Be Blessed, DTG

[@keymilner]

Thanks this was very helpful, my girlfriends just got stuck closed and now I atlest have an idea of what to do.

[@whybuytherecom]

glad to hear the video helped... good wrenching!

[@truthbomb3862]

Try not to completely remove that bottom bolt. It looks nearly impossible to get it started if it falls out. I got lucky and didn't let it come all the way out. Put something on the rubber seal to hold it in place so you don't cause it to slip out and cause the housing to crack as you slide it into place to tighten it down

[@truthbomb3862]

Lay a towel under the housing in top of the trans so you don't have to crawl under it to retrieve the wrench you'll probably drop 15 times during the ordeal.

[@nathanb701]

Good video brother

[@DavidTGould]

Thank you... Appreciate it. Be Blessed, DTG

[@punesherrangers2752]

That hose that broke... Where does the other end go? When I wiggled it out the other end wasn't attached to anything. The whole hose came out. Not broken just not attached

[@DavidTGould]

Hope this helps: www.google.com/url?sa=i&source=images&cd=&ved=2ahUKEwjBv5HmpvngAhWQc98KHTj6AYkQjhx6BAgBEAM&url=https%3A%2F%2Fwww.2carpros.com%2Fquestions%2Fwhat-is-this-part&psig=AOvVaw3NuST6b6HDAdO_rqNGliCe&ust=1552366683899122 - Be Blessed, DTG

[@thayneheath8888]

If you loosen that black tube and pull it to the side, you can put that bottom bolt back in from the top, which is easier to do that trying to get it back in from the bottom. Put the bottom bolt back in until it just get started, you need as much room as you can to allow the slotted hole on the housing to slip over it. With the black tube out of the way and holding the thermostat with a screwdriver, slip the housing down with the slotted hole over the bottom bolt. It is tight, but can be done.

[@whybuytherecom]

mine was rusted... concerned it would make repair bigger if cracked coming off or on. thanks for sharing!

[@truthbomb3862]

I tried but didn't help much. I used a standard open/box 6 point wrench and it sucked. Felt cross threaded and I could only turn it 1/16 of a turn at a time.

[@truthbomb3862]

One thing that did help me was leaving the bottom bolt threaded in a short way and cutting half the slotted side off with a die grinder. It let me slip the housing over the thermostat and then around the bottom bolt. When I took it apart the only part of a thermostat was the top piece. Looked like someone broke the rest off and left it out.

[@truthbomb3862]

It took me 2 hours last night and about two hours today to get it done but I probably smoked $50 worth of pot to keep from having an anxiety attack sitting there for 30 minutes getting that bottom bolt lose and another 30 to tighten it back up.

[@hotboxmyelevator]

@@truthbomb3862 Are you me? I had the exact same experience

[@JasonHenderliter]

I appreciate the input, but I have no idea how you got the rear/ bottom bolt loose with a ratcheting wrench. I bought a 13mm ratcheting wrench specifically for that purpose. I was unable to even get the ratcheting side on the bolt as the housing doesn't allow enough space to even get on it. I have worked on GMs most of my life except the last few years and this may be the last one I ever work on as the Aztek curse has taken it's toll on me.

[@whybuytherecom]

Sorry that did not work out... the thickness of the ratcheting wrench OR if it is angled may be an issue. the one in the video is a GearWrench. NOTE: wrench is inserted from just about directly from behind. the ratcheting wrench is just to break the bolt loose (that was the hard part for me)

[@whybuytherecom]

IF this helps... www.amazon.com/ATD-Tools-3310-Thermostat-Wrench/dp/B00H2VV0UE

[@herb2241]

Distributor wrench grind down so it's real thin walled have to move it a bunch but gets in there and you don't have to be double jointed

[@truthbomb3862]

I definitely don't want to tackle that bottom bolt again. GM dropped the ball with the entire engine design from the 3100 to 3400 in my opinion. This Aztec deserves 50 lbs of tangerine as far as I'm concerned.

[@DavidTGould]

update: kzbin.info/www/bejne/gmfJY6OdfMuegMk for "water bottle trick" air bleed of Dex-Cool Anti-Freeze. Don't forget to turn on heat and fan in vehicle to get air out of heater core / dash hoses.

[@nadiahill8314]

Omg thank you. That thing has been giving me so much trouble.

[@whybuytherecom]

IF this helps... www.amazon.com/ATD-Tools-3310-Thermostat-Wrench/dp/B00H2VV0UE

[@whybuytherecom]

update: keep an eye on thermostat opening and closing properly... air bubble can stop anti-freeze from reaching thermostat delaying opening and causing overheat on initial start up. IF this happens... pull over (don't keep driving) let car sit a couple of minutes... Anti-Freeze opens thermostat, temperature drops to normal THEN proceed. Air "bleeders" are left front above alternator and rear top back of motor. In my case I don't think I opened the heater core (turn temp knob to hot) video: kzbin.info/www/bejne/l5WcpmugdqmlrLc

[@jamesholley1189]

I you could have removed that manifold crossover pipe, that's easy to do, to allow you better access to your thermostat housing.

[@maggiehumble7822]

Replaced heater hose and drove it 2 miles and car just up and stopped,,now won't start...

[@grandam]

Probably the infamous GM security system

[@bobdeardoff5319]

Thanks!

[@chrispellicci6587]

Was your thermostat bad, did you test it?

[@babna7518]

Muchas gracias!!!!!! 🙏👍👨‍🔧🧰⛽⚙️🔧⛓️

[@harrypalmer728]

Save yourself a lot of time by removing the throttle body, takes about 15 min, you have easy access to the bottom bolt this way and you can clean the throttle body at the same time. This does save time, headaches, and busted knuckles.

[@ken-dt1zp]

What is ideal to clean on the throttle body?

[@harrypalmer728]

@@ken-dt1zp Just regular carburetor cleaner and a clean rag

[@rickcreamer1707]

Buick rendezvous 2004 thermostat replacement

[@williamstorm6332]

it makes life so much easier to just remove the thottle body. so much more room when done that way.

[@robertschiedeck80]

Exactly for $1.45 for the gasket take it off

[@josephseno8272]

@@robertschiedeck80 - Thats exactly what I thought too. I’m actually working on an 04 Aztek, and just did the same thing. The bottom bolt is still a bitch to get in, but removing the throttle body gives you more room.

[@Truelivejayy]

That 3400 is a head gasket nightmare

[@timothyunterthiner2637]

I hate GM for this thermostat housing design. A simple replacement made extremely frustrating, complicated and on top of that I got constipation cramps doing this. Now I’m angry and on the toilet watching this video 😡

[@alexpagano1000]

The easy way for and faster way is i take the carburator out. I do that job in 30 minutes or less in my chebrolet venture 3400 for me is more easy for work them u got more space for work the carburator is easy to take out. The way he does take more time and u don't have space when u put the new one back and problaly it will lick. And u will have problems with that again. And i clean the carburator too i do that very easy them i can use the same gasket for the carburator. The point is this u do a better job and u don't have problems for posible licks

[@DavidTGould]

Alex... thanks for your reply. I admit to being a somewhat technical guy who happens to work on cars in his driveway. I am not a mechanic. I think I remember trying to get to the carburetor bolts and having difficulty with one of them... Does the black antifreeze pipe that wraps around the front block access to one of the bolts? I could not get that pipe off without destroying it... It has been some time since the last thermostat repair attempt. That is the real reason I came up with the rear bolt access. Since then the head gaskets were replaced... Car running like a champ currently with 168k miles. Thanks for your input. Be Blessed, DTG

[@kelleycondon6504]

That little plastic pipe broke on e in the exact same way

[@estelahernandez1193]

Alguien que me lo tradusca a español 😅

[@DavidTGould]

preguntas?

[@Felony_pranks]

I hate the Aztek , bought it for my girl and every simple little job is such a hassle

[@Felony_pranks]

But this video really helped , keep it up

[@Idkgoogleitbro]

@@Felony_pranks no kidding even changing the belt was surprisingly challenging...pontiak left no room for maintenance.

[@mrhamburger6936]

this job requires the work of a magician or magic hands and Magic tools I just replace my thermostat that's the same size motor it was a b**** I use the same tools as you did

[@DavidTGould]

I agree... not easy at all. having had to remove the thermostat (3) times I hope some of the tips in the video help. (poor design for part that requires maintenance)

[@mrhamburger6936]

David T. Gould I found out there's a special wrench for the thermostats gm 3.1 Google thermostat wrench 3.1

[@whybuytherecom]

Ha! that tool looks like the position you have to make with your arm to get in there... here is a link: www.amazon.com/ATD-Tools-3310-Thermostat-Wrench/dp/B00H2VV0UE

[@whybuytherecom]

looking at that tool... being closed box it looks like it may get stuck once bolt is backed out half way... if I did this job for living I might consider cutting the boxed wrench open like those used for brake lines... just a thought.

[@mrhamburger6936]

You can get a distributor wrench from Napa it's a 13 mm and a 15 part number BK 776 9228 this wrench will work very good and it's cheap 9 or $10 you may have to heat up the wrench at the bend and give it a little bit more of a Bend Napa also has the special wrench to do the job 21.99 is the cost

[@maggiehumble7822]

I guess a answer now ,,I won't get one,,

[@JustinSmith-hr6qg]

Everyone with a 3.1 or 3.4 thermostat replacement video has some lame ass excuse as to why they didn’t record the re assembly portion. Dead battery, video was garbage, didn’t have audio for some reason etc etc. just so happens to be the shittiest part of the whole job. Yep I’m here with a bottom bolt that I can’t get started. Shit.

[@DavidTGould]

Justin... I am sorry your having a hard time... that back bolt is tough... try viewing 15:47 of video (I used my cell phone so I know it is not great) to see how I started the bolt threading without the thermostat cover to make sure bolt / threads align and did not get damaged when removed (mine was damaged and would not have threaded without cleaning up threads prior to reassembly). Note: the duct tape on the ratcheting wrench can not extend over side the way I showed in video (or ratchet will not turn) just a little past the bolt head OR thin paper / tape between bolt head and ratchet wrench to hold bolt in place while turning did the trick of keeping the bolt stationary while only using one hand from back to line up. Once threads are confirmed good and bolts are confirmed for front and back (particularly the back) you can then put in thermostat and cover. I lined up rear bolt 1st from the back with one hand and used a long flat head screwdriver from the front to apply pressure in as I turned clockwise enough to get the bolt started. Bolt only turned a little bit each time to start. Once bolt was started and I could back off ratchet wrench I turned wrench around to open side to make tightening faster. Be sure not to tighten rear prior to aligning and snugging down front bolt. I was able to reach the front bolt with a universal socket. Typical time for me (having done this 3x) is still over an hour with that back bolt. Hope this helps.

[@JustinSmith-hr6qg]

David T. Gould wow David thanks for the response, I’m pretty frustrated with this bolt, thanks for looking past my crummy attitude and offering some more advice. Good man!

[@mattcareyote1746]

This is bs ratchet wrench don't fit. Literally can't get my hand anywhere near it so even if I got the bolt out there is physically no way to reach it to put it back it. On top.of the fact that no one is showing the thermostat going back in cause it won't fit without that tube out of the way.

[@DavidTGould]

Please see video: about 10:40 covers removal of pipe. Note: if yours will not come out you likely have the same issue I did with thermostat sticking to pipe (vs engine block) Watch video a few more minutes for description. I know your pain very well. After about the 6th time over 5 years I figured out (maybe not the best video, sorry) that I could get a low profile rachet wrench to release the bolt... only a few turns... then remove rachet wrench (otherwise it will get stuck and not come out) and use conventional open wrench 1/4 turn at a time flipping the wrench to catch the bolt head. This is slow but not as slow and removing all of the piping. Reinstalling bolt was taking duct tape across manual wrench to get bolt to "stick" on wrench long enough to get 1st threads started... then twisting wrench released bolt head from tape.... then 1/4 turns tightening until you can get clearance for the ratchet wrench back over bolt. Lastly, tighten bolt with rachet wrench to get torque required for no leak. Hope this helps. Be Blessed. DTG

[@hugh3rdof5]

This video right here explains why GM went bankrupt -- and even more why they're giving up on cars going forward. (while Toyota rules) Extremely poor design. Mechanics & stealerships only "love" the 3.4 engines, especially the ones jammed into the Montana/Venture models..... "love" them because GM IDIOTS design a thermostat that takes HOURS to remove..... whereas on most vehicles, it's a 5 minutes job total. (perhaps deliberately) ps, absolute mistake putting permatext in there... ps, shop manual directs us to remove the wrap around pipe. (I found just loosening works "enough.") Another workaround -- remove throttle body and even EGR valve -- gives more access into the back. See also RichPin's brilliant 2010 video on dealing with these gm t-rexes.

[@DavidTGould]

Thanks for the tips! Other viewers will benefit. (I think our 3.4 has finally given up for ghost at 174k miles. Believe it or not a broken camshaft. Never heard of such a thing. All the best to you and others, Be Blessed, DTG

[@arturomedina9769]

Mucho bla bla bla bla bla bla bla y poca acción

[@jybarraii]

Never posted on a youtube video before but have to give credit where credit is due!! Thank you for doing this and posting!!! OU THE MAN!!

[@DavidTGould]

glad this video helped. thank you