2003 BMW 325i E46 | P0118 ENGINE COOLANT TEMPERATURE SENSOR REPLACEMENT *THE FAST WAY*

How to remove the cylinder head ECT sensor without removing the intake manifold. OBD II code was P0118.
I was not able to film it after the repair, but the gauge operated normally after the sensor was replaced.

[@roaldsimonson1672]

Thanks so much for this video!!! It emboldened me to give it a try. When I brought my 2002 325xi Wagon into the BMW dealership for that airbag recall that happened I paid them to run a diagnostic while they were at it. I also had had an OBDII P0118 scan code as well. BMW confirmed that ECT sensor was faulty and needed replacement. They quoted me a 4.9 hour job (removing manifold and all that) costing $835! So I searched forums and videos far and wide for another way and eventually I came across your video here. I've just completed the job! Respectfully I have some suggestions for future viewers. Two of the most time consuming and tricky steps of this task as you've demonstrated is clearing space by removing that air intake tube and that master cylinder shield thing. This doesn't actually need to be done. I didn't need that space created by doing so at all (nor was it necessary to remove the air box). The important thing is to remove all that air filter cowling assembly as you show - in particular that last plate covering the air intake and wiper transmission. That's all the working space you need. My much more experienced and equipped home hobbyist mechanic friend and I then went in and felt around and found the ECT sensor - eureka! We assembled your socket/joint/extension system but before going at it I said, You know, I wonder if that specialty offset socket thingy I bought for when we replaced my oxygen sensors - Oxygen Sensor Removal Tool, 22mm, 3/8 in. drive - I wonder if that would fit? It fit perfectly. All you need from there is a basically a straight foot-long extension and you can snap it loose in a second. (In addition I had bought an inexpensive wifi smartphone endoscope in anticipation of this job so that we could go in there and look around and see what was what and what we were doing. This was really fun and gave us security but it wasn't necessary.) All in all this is a 20 minute job. In the end I am really mystified by the BMW dealer quote. Maybe they have a company policy that nothing can be completed by "feel" and that everything requires actual eyes to be laid on the job. I dunno.

[@samg5543]

The BMW dealer would have quoted a standard "book time" for the job, but I would bet the tech would have used this method and made a bunch of money off of you. Good to hear it helped you. Some of the parts I took off were already off as part of a collision repair.

[@FELIPE8226M]

The stealerships are crooks of course

[@alperenerol1852]

You're a legend. Used the longest extension I had with 7/8 and it worked! Guess I'm not paying 300 bucks for the mechanic.

[@fabzahd]

Great video and explanation. As a result, I was able to get the sensor changed within 45mins as opposed to the 4 & a half hours it took me to remove the intake manifold a couple of years back.

[@larryklassen5520]

Oh another thing is I never drained the coolant and didn’t lose a drop. Not sure if you had drained the coolant or mentioned that it wasn’t necessary. I wouldn’t have thought replacing that sensor was possible without removing the intake without your video. Thanks!!

[@samg5543]

I had already drained the coolant to replace the radiator from a collision, but you could probably do this job without draining it. You may lose a little, but probably not a lot.

[@winthedaymusic]

Thank you so much for the video! Saved me hours! I wanted to share my experience on my BMW 2000 323i... I'm a small guy so... I was able to access the thermostat by only having to remove the cabin filter/tray and the firewall plate behind it. The only other thing I had to do was unbolt and lift the fuel rail because there were two down pipes coming from the fuel rail that were in my way... Don't remove the injectors from the rail, just remove the four bolts holding it down and lift straight up with a gentle rocking motion back and fourth. When you re-insert the injectors back put a tiny amount of lithium grease on the o-rings to help the seat correctly. Took me around 20-30 min..

[@samg5543]

winthedaymusic you're welcome

[@alfrednavarro2391]

Sam, what works better is an open 12 point crow socket. This way you don’t have to worry about depth. I had the sensor off and replaced in 20 minutes.

[@samg5543]

Good job. I don't own any crow's foot sockets

[@larryklassen5520]

Great video thanks. I used a 22mm stubby box end wrench which worked perfectly also.

[@samg5543]

Good to hear.

[@stevenoxendine4659]

this really work but we use an 22mm oxygen sensor besides regular 7/8 socket had it done in 25 minutes, and this fix my car thanks for your video it same time besides taking all that manifold off. CAADOX trucking thanks

[@southofheaven123]

Thanks for making a video about the difficult to tackle coolant sensor- anybody could do the lower radiator hose one without a video but this one takes a little more headscratching!

[@Silvershadow1978]

Sam G is a genius . This is one of the best DIY to save time for the BMW 330ci projects. Thank you Kindly for the video. Thanks for sharing

[@jonesvaughn8946]

Hey I have a question because I have a 2000 528i and I was wondering does the engine sensor have a connector that has to be plugged into it after you put it in and also is it the same type of sensor as the engine coolant sensor that's below the coolant reservoir?

[@ramongambino1977]

thanks for the video . I've taken the manifold off 3 times previously to replace hoses , starter manifold gasket . I dreaded taken it off again . just replaced the sensor ! great detailed video !!

[@samg5543]

ramongambino1977 you're welcome. glad it's helping people.

[@jayparker6114]

helped me fix my problem. i didn't realize that connector on the end of that wiring harness was for the engine coolant temp. sensor but it makes sense 'cause my car started overheating after the ccv replacement and it wasn't before. thanks a mil! i was procrastinating fixing it because it's so hard to find info. sometimes but you got me right to the answer almost immediately!

[@shawnheather323i]

This worked for me! Thank you for helping me avoid taking the manifold off! I ended up using a crows foot o2 sensor removed to take the original 22mm off. Then I used a crows foot 19mm to put the new one on

[@samg5543]

Glad it helped you out. thanks for watching.

[@franciscomorillamoreno5240]

Que falla te saca con ese sensor ..nose se si con ese sensor molo no te arrancaban

[@lascellesjohnson2787]

Thank you very much for the video. This has saved me a ton of time and money. I’m located in the UK and have a 2001 BMW 330i e46. I had the P0118 fault code. The symptom in my case was as soon as I started the car from cold the temperature gauge would shoot up to the red and stayed there for most on the time. Sometimes it would read normal and on other occasions would read cold when the engine was hot, this would result in a higher than normal engine idle speed and difficulty restarting the engine when hot. Replacing the Temperature Sensor fixed my problem.

[@isrealperez9069]

Thanks for your video it help me out and yes it was a lot easier to remove I used a 02 sensor adapter to remove the sensor have a bless live thanks

[@MrBadbrad84]

Saved me a bunch of time. Appreciate it!

[@failuremachine2414]

Sam thanks for the great video. I would like to supplement your fine work. You can do this even easier by eliminating the swivel attachment and going right under the manifold. It is a straight shot at the ECT sensor. (I used wobble extensions) Hope this helps.

[@Spaginni]

I haven’t tried it yet, but thank you. I’m not into taking the intake out to replace a stupid sensor I knew to change when I saw it.

[@kyleenriquez5605]

I have this exact sensor and dammit god bless a good ol boy to find a better way.

[@hindflight]

Sam G you are awesome sir!! This is a huge time saver!

[@hueyp614]

You the man bro I'm about to do mine. A true life saver🎉

[@rontobisch9765]

Thanks for the knowledge, doing this job without taking all that other stuff off, legend mate, cheers.

[@goldbond8884]

Hey this video was a life saver! Thanks for posting it. I had already removed the intake manifold to replace the heater intake pipe and a water pipe. Apparently when I reassembled everything I neglected to plug the engine temp sensor back in and when I turned the ignition on the temp gauge pinged to red immediately and the obc read -128. I was dreading having to take the intake manifold back off, but after stumbling upon your video (spend the better part of two days combing over bmw forums for any tips) I didn't have to. Saved me probably 4 hours of labor.

[@samg5543]

Gold Bond you're welcome. Glad it's helping people.

[@Mysticlyonenterprise]

Thanks again buddy.doing this job again.I for the sizes you used on the extensions n sockets.👌🏾👍🏽

[@mars7357]

Yo you saved me so much time

[@MartyHaloMeyer]

Thanks for the Video, car has been running a bit cool, I had replaced the other sensor, had this one on the shelf waiting to do it when I had time to remove the intake. Now I don't have to wait!

[@samg5543]

glad it helped.

[@jesusdiazdeleon1121]

MADE MY JOB SO MUCH EASIER! Thank you!

[@regibson23]

Awesome video. I was doing a cooling system overhaul so picked up this sensor on a whim. Seeing how big a pain it is I think I'll pass. But great to know you don't have to pull the manifold.

[@davem8165]

Thanks for the video, HUGE time saver!

[@willyoriley775]

A crow's foot works a lot easier. Great video!

[@samg5543]

If you have one

[@tiller1205]

You are the best honestly bro wow thanks so much

[@jessebernard3434]

Gr8 video. Well explained. Thanx. If this sensor is bad can it send the car into limp mood?

[@samg5543]

Jesse Bernard I believe this sensor has one pin for the gauge and a separate pin for the PCM. if the pcm part of it goes bad, it's possible it would go into open loop (sometimes referred to as limp). you would need a scan tool to read loop status while it's running.

[@tristanwalton8198]

My 01 x5 4.4 went into limp mode. Gauge said it overheated while driving from my corner store. Then said trans fail safe and cut off. Now it won't crank at all. And the temperature gauge goes straight to red while trying to start it. Nothing. Can you please give me some sort of insight on to what you think? Could that sensor prevent it from cranking? Good battery, connection, starter, fuel pump, fuses, even unhooked the abs. I'm so confused. Please help.

[@locca6]

Thanks Sam G for the video. I had the same socket setup and it actually worked!!!

[@samg5543]

Quentin Jenkins you're welcome. i knew it would help someone.

[@jessebernard3434]

Thank you sir. Did appreciate yr kind and fast response. Reason for asking is I have an 02 325i BMW and the maf sensor went bad.I drove it around for a while with the maf unplugged.Now I put in a new maf and even if it is plugged or unplug the car stays idling as normal. It has no jerking, misfires, I mean I can go as much as 60 mph. But I don't know the issues with the maf sensor. Any help will be greatly appreciated. Thanx

[@samg5543]

Jesse Bernard if you know the maf was bad, then you should have no issues now. do you have any codes now?

[@jessebernard3434]

Yes there are some codes.Probably Monday or TuesdayI will send it in to the shop. I will definitely let you know the codes sir. Thanx again.

[@iListRealEstate]

I heard a rumor this was possible without removing the manifold but now I know for sure. Thanks man! Was your temp gauge acting weird at all or was your only symptom the P0118?

[@samg5543]

Cody Kownacki you're welcome.

[@samg5543]

Cody Kownacki gauge was dropping out to cold when the car heated up. this was not my car. it was a customer's. that's the only symptom i could reproduce.

[@rsrdan]

Thanks. This worked perfect. .....great video

[@samg5543]

You're welcome. Glad it helped you.

[@jongkeunlee]

Great job. Thanks for sharing. You think is it possible to replace a starter w/o removing the intake?

[@samg5543]

Don't know for sure. I do mostly body work.

[@jongkeunlee]

@@samg5543 thanks

[@jonesvaughn8946]

I have a question when you take that stuff off from the back are you able to then see the sensor or even feel the sensor with your hand so you're not blindly trying to put the tool back there to take it off?

[@samg5543]

I don't think you can see it without a mirror but you can feel it if I remember correctly

[@jonesvaughn8946]

@@samg5543 thanks for the reply. Also do you have an estimate on how long it took you from start to finish including taking plastic parts off the engine to get access to it

[@jonesvaughn8946]

@@samg5543 and is the sensor the same sensor that's below the coolant reservoir and does it connect to anything like the sensor under the coolant reservoir does

[@robchapman1162]

awesome, thanks I've spent day's try to locate this sensor! lol sucks I have to take apart half the car again! I had to change the expansion tank an fan! An no heat!! is this my problem? I have had similar heat lose issue's with my old chevy! An this was the problem! any input or answers? thanks for your time!

[@samg5543]

This sensor should not affect your heater in the car, unless the car has auto heat control that is tied to the engine temp somehow. If you have not heat, the most likely things are low coolant, a bad water pump, or a clogged heater core.

[@bluez81]

Thanks soo much dude for this video!!

[@samg5543]

No problem. Hope it helped.

[@Icanhasmycheesburger]

Hey, thanks a lot for the great video! just a quick question: will the car leak coolant from the hole after you pull/screw out the sensor? I'm gonna try to do this later this week since my gauge shows a constant 128 degree (C), even after a day standing still.

[@samg5543]

It will probably leak a little coolant out if your system is full, but I had the system drained for the collision repair, so nothing came out.

[@Icanhasmycheesburger]

Sam G all right. I'll just have something to stop most of the coolant handy when I take the sensor out. Thanks for the tip.

[@patrickr.sansonetti3237]

Would this sensor being bad cause my thermostat to not operate properly, causing an overheat situation? The entire cooling system has been replaced, head gasket it fine, system pressure tests fine, but still indicates overheating after about ten minutes. Please advise.

[@samg5543]

If your thermostat is electronically controlled, then it's possible that this sensor reading low could prevent it from opening. If it's a regular mechanical thermostat, then the sensor should have nothing to do with the cooling issue. Make sure the water pump and fans are working

[@taylorwest6986]

Thank you, kindly!

[@ThePs3ownsss]

How’d you get the crush washer off the block I’m having troubles 😂

[@samg5543]

I don't remember having to do that. Must have come off with the sensor

[@jaguar7051]

How do you unplug the electrical connector from the sensor?

[@samg5543]

I think it just pulls off by hand

[@wilvandermeulen4930]

Brilliant!!!

[@mirandaruiz8112]

Does a 2001 bmw 325i have this sensor as well ?? or just the one sensor on the right side of the radiator hose

[@mirandaruiz8112]

Please help

[@samg5543]

@@mirandaruiz8112 not sure but it probably has this sensor

[@sebastienportel3138]

Merci pour les informations

[@disgruntledvet11b18]

Outstanding. Just the advice I was looking for. I took my sensor out of the cylinder head during a head gasket job and forgot to screw it back in before I re-installed the cylinder head. I already put the entire engine and manifold back to together, and after boggling my mind as to where the final electric plug for the power strip connected to the fuel injectors went for over 2 hours, Finally I looked down through the intake manifold and saw a wide open hole in the cylinder head....of course, it was the empty threaded hole leading into my cylinder head staring me in the face. I found the sensor in my "other" box of connectors. Im going to give this a try tomorrow. Quick question...is there supposed to be an o-ring pushed into that hole in the cylinder head before the sensor is installed and tightened down? Or is the metal washer in it enough to seal it, like a crush washer for an oil line? Hope to hear back from you soon. Thanks for the video. Peace

[@samg5543]

Yes, crush washer is all it needs.

[@disgruntledvet11b18]

Sam G my cylinder head already had an o-ring inside of the hole where the sensor goes. Anyways, I was able to get the sensor in a millimeter at a time using just my fingers, and got it "finger tight". I then attempted to use the joints extensions like you did here to tighten it better, but I lost a few sockets in the process and wasn't able to grab onto it. The thing is in there as tight as I can get it by my fingers but isn't torqued down properly. I haven't even filled the car with fluids and started it yet, but do you think I'll be ok with it just being finger tight? It will i definitely have a leak? I really don't want to pull the whole intake manifold off. I'm thinking I might go buy some more sockets and give it another go. I only need to turn turn the thing another 8th of an inch for it to be really "tight"

[@samg5543]

@@disgruntledvet11b18 it has to be tight to seal since it is under pressure

[@disgruntledvet11b18]

Sam G update: after reading some of your viewers comments I decided to try a 22mm (3/8 drive) crows foot oxygen sensor socket. I was able to get the socket on by fishing it back through the area you are going at it. I was then able to situate it on the sensor so that the socket hole on the sensor socket was visible through the last 2 ribs of the intake manifold. I slid a foot long 3/8 drive socket into the slot and was able to turn the censor another 1/8 of a turn until it stopped. I feels pretty tight, not sure if it will go Any tighter since the plug on the end would no longer be oriented straight. I'm pretty sure I've got it "tight" now. I will let you know how the car runs once I fire it up next week. Thanks again

[@lakerland24]

I have a question, I recently bought a 2000 323i and I’m getting a fluctuating temp gauge. The car is not running hot or over heating. I scanned the car before it was bought and showed no codes. Can this be the possible fix for this temperature gauge fluctuating?

[@samg5543]

It's possible and likely.

[@lakerland24]

Sam G what are other possibilities if you don’t mind ? Thank you for replying as well

[@samg5543]

@@lakerland24 you would need the circuit diagram to determine all possibilities, but it could be a bad gauge or bad connection/wiring, but most likely it's the sensor if you have to guess. It's best to diagnose it before buying any parts, but the sensor is not too expensive if you want to just try it first and you don't have much experience with troubleshooting and diagnostics.

[@samg5543]

@@lakerland24 it is most likely a voltage divider circuit withthe gauge and sensor in series, but also could be directly reporting to the computer and gauge controlled by computer. I'm not sure. That's why the wiring diagram is important.

[@lakerland24]

Sam G makes sense. I reset the instrument cluster and it seem to have done the trick but I’m not sure I’m going to follow those steps you listed above to really be sure! Thanks again man you’re the real mvp

[@jacksonsdad1]

Hey Sam G. Many Thanks for the informative video. I'm pretty sure that sensor is the culprit on my 'warm restart' condition. My 2004 325ci fires right up when it's cold or hot but if it's been sitting for a half hour or so I have to crank it over a couple of times to get it started. It always starts and smooths out after a few seconds but you can smell how rich the mixture was... almost like a partially flooded carburetor 'back in the old days' ;o) My question is... do you think a 7/8" (or 22 mm) closed-end or open-ended wrench might work to 'grab' that nut? I've ordered the sensor. It will be here Thursday and I'm getting the tools together that you outlined in the video but I'm not sure yet if I have a socket of the proper depth that you recommended but... I know I have a wrench of that size and just thought I'd ask as it's obviously pretty much a blind job. If you think I can get a wrench on it then that's a relief but if I need to purchase a socket like the one you described then that's no big deal... just another tool for my box. Also just for my own info... I saw where you said the new part was a 22mm nut --- do you think that same size socket could be used for the removal of the old sensor? Pretty sure I have one of those that would suit the purpose. Thanks Again for the tutorial. Everything else I've found has said "just live with it unless you have to have the transmission or engine removed b/c it's nearly impossible to get at".

[@samg5543]

jacksonsdad1 I'm not sure that a wrench will fit, but maybe. I don't have a 22mm wrench, so I never tried it. The hex on the new one should be the same same, but can't remember. I would buy a socket just to be safe.

[@jacksonsdad1]

Thanks for the reply Sam. After browsing through my tool collection I was able to find everything you recommended... even the 7/8" socket measured out perfectly. Just waiting on the part now. I'll let you know just for kicks if I'm able to get my 7/8" wrench on that thing to get it out. Thanks Again and Keep Up The Good Work!

[@samg5543]

You're welcome. Let us know if the wrench fits.

[@jacksonsdad1]

Will do. Weather permitting I'll do the job on Saturday. One more question... in the meantime... do you think it would have any negative effects on driving the car between now and then if i go ahead and take the cabin filter and housing off now? Wouldn't mind getting a jump on it.

[@samg5543]

should be fine as long as you don't let rain/water into the cabin.

[@erikth126]

Has anyone tried this on a E46 M3 with the S54 Engine? Any chance there is a similar procedure?

[@scooter1391]

thank you so much I was about to pull my intake off to do that I'm not now thanks to you

[@VQMikeyProductionz]

Dude fuck ya. The best

[@tomnastzy3211]

Cut the box end off 22mm wrench and leave about 3” handle. It’ll fit between the sensor and the firewall and give you enough leverage to loosen it. The sensor is not torqued very tight into the head.

[@kennyspringer7668]

Is this and M54 3.0 if so is it the same on a M54 2.5

[@samg5543]

I have no idea. I'm not a BMW guy. Just did this job while it was in for body work.

[@kennyspringer7668]

Alright cool thanks for the response

[@lukas______]

the real question is, did you charge the customer the full labor cost including pulling the intake or not? hahahah

[@samg5543]

Haha. I only charge for actual time typically.

[@therealzooch]

Did this fix the guage?

[@samg5543]

Yep sure did

[@elmasejerome5394]

You don't have to go to all that just to change your BMW sensor

[@samg5543]

Ok, well show everyone how to do it on your channel then.

[@jtaylor4027]

Shade tree mechanic learning on the go and making videos. So many excuses when diagnosis was wrong and it didn't fix the problem. I forgot to film it. Give us a break.

[@samg5543]

This did fix the problem. The video wasn't a diagnosis/fix video. Just showing people a way to swap the sensor without removing the manifold. The diagnosis wasn't the point of showing this, that's why I filmed it after the repair was done and I knew the process worked.

[@davemccheyne8836]

This

[@jaguar7051]

You nothing done You are a cheap actor

[@Jethrumi]

Come again?