Mercedes Crankshaft Position Sensor (CPS) DIY Change on R129, W124, W140, W201

[@markobrien6586]

val again another excellent video !!! fellow r129 owners need people like you and fellow you tubers need all the Diy help we can get!!!!!5 stars!!!

[@HandyVal]

Thank you for your amazing review! I’m just getting started - many more videos on the way.

[@markobrien6586]

val excellent video!!! especially Sl 500s cps problems and Diy install we need more videos like cam position sensors etc. as always excellent content!!!!!!!

[@HandyVal]

Thanks Mark! The camshaft position sensor is a similar serving sensor as the CPS that measures different parts of ignition timing. Its replacement is a lot simpler, as it is easy to get to - eyes and hands can work together! I made a video on it, hopefully you'll find it helpful too: kzbin.info/www/bejne/aaiXe6mdmKyenKc

[@clemensklosterer1342]

Amazing videos encourages me to work on my 1993 m104 sl320. I do have some idle issues where the engine runs smooth but occasionally at too high rps as well as my fans not coming on... fighting to keep the old dream car of my father alive

[@HandyVal]

I certainly encourage everyone through my videos to try DIY on their R129s. It may seem daunting at first but after a while comfort and confidence builds. The 320 has a great engine. Try a fuel injector cleaner from LiquiMoly, it may cure your occasional idle problem.

[@kikiblue94170]

I am new to your videos, just Baugh a 1993 300sl, they are excellent !!! basic, very clear and easy to understand, thank you very much. I keep watching one after one even if I don't need the information at the time. just having great time. excellent content.

[@HandyVal]

Thank you. Much appreciated.

[@alpanosap]

Thanks for your excellent and clear explanation which makes it easy to understand this sensor performance to everyone.

[@HandyVal]

Thank you. I appreciate it. Your comment encourages me to keep making more videos on these great cars. More videos are on their way...

[@richardcatherall2098]

Excellent content Val. Chalking this up for my w124.

[@ChristopheZ]

I had a hot start issue and sluggish acceleration when engine was at temperature. Car would take about 2.5 seconds to start instead of the usual 1.2 -1.5 seconds....turned out my issue was a bad CAMSHAFT position sensor....put a new one ( 10 minutes job on my W124 400E M119 engine), and it was back to normal.... At that time, I also checked the ohms on my cranshaft sensor ( like you did), and it was around the 0.8 range ( which is good)

[@HandyVal]

The camshaft sensor can also cause a variety of starting and performance issues and is a lot easier to change, given its location and visibility than a crankshaft position sensor. I made a camshaft sensor video too. You did the right thing by testing and then keeping your current crankshaft sensor. Thanks for sharing your experience - it's all very helpful for the Mercedes DIY community.

[@codyturner9402]

Do you still have the 400E @ChristopheZ

[@markbaker6029]

Thank you Handy Val - excellent video - once more you’ve given me information that I WILL use for my 500SL…

[@HandyVal]

Thank you. Super happy to help out.

[@RobertSmith-di5ll]

Wonderful - I keep a spare in the car but had no idea what or where it lived - brill

[@samuelberkun9788]

I have a 95 SL500, I thought my wiring harness was shot but it turned out it was jut the CPS..... Car was mis firing, back firing, running rich and stalling bad when warm, wouldn't even turn over when hot. New CPS fixed the issue!

[@HandyVal]

Awesome - it's a great feeling when one part change (and a relatively inexpensive one to replace) makes many, many problems go away!! Thanks for sharing this and I'm glad you are back to enjoying your SL.

[@v4der999]

you are a genius! thank you!!! Greats from Georgia!!!🇬🇪

[@HandyVal]

My pleasure! Thank you.

[@markbaker6029]

We’ll done Val - I appreciate the time you spent on this instructional project! I’ve placed it in my library of future Maintenances. Blessings…

[@michaelsliwinski8044]

Thanks for sharing. Helpful video.

[@HandyVal]

Thank you. Glad it was helpful - much appreciated.

[@brandonfowler6013]

Great video Val!

[@XSAILOR65]

FEBI BILSTEIN CPS is also really cheap, usually a decent brand. Is it important to disconnect the battery when doing this( on a R129), assuming the risk for a short is pretty limited during this procedure? Great video anyway!

[@HandyVal]

Febi Belstein is a very good brand. I didn’t know they made a CPS. Febi is mostly known for their suspension parts. It’s always best to unplug the battery, as it avoids any mishaps, but not necessary for this change. What’s most important is that the key stays away from the ignition, that’s where you could run into a problem with shorts and unintended consequences.

[@XSAILOR65]

@@HandyVal OK, thanks' for comment. here part number: FEBI BILSTEIN 30689 , the price in Europe is 25-35 eur only. Will change mine, just because its so cheap. I might hav the original one, now clocked 275000 km

[@HandyVal]

Hi. The Febi 32421 is a camshaft sensor, not a crankshaft sensor. Make sure you order the right part - mistakes happen.

[@XSAILOR65]

@@HandyVal Hi my bad, thanks for checking. I updated the right part number in my comment to avoid errors. Price still about 25 euros.

[@JOHNVASSIL]

Excellent video Val!! My 1986 300E has a hot start issue only when the car is not run for few days, for instance it would start great after a week parked in the garage but once I drive away for couple of miles it would stop once engine is warmed. Then it would crank but would not start until 20 minutes later it will run fine. Changed sparks, coils, EZL, fuel filter, fuel relay, radiator, water pump, belt tensioner, thermostat, over $3k spent but still does it. I checked CPS cold resistance is 840ohms and hot about 970 ohms. What would you guess might be the problem? Much appreciate you in advance!

[@HandyVal]

Thanks John. Let's try to fix this hot start issue. A hot start issue can be caused by a faulty CPS and your CPS is within specs, however, even though, it's within specs you are experiencing the classic symptom of a faulty CPS so you should change it. Another fault of a hot start issue is a malfunctioning coolant temperature sensor. The coolant temperature sensor informs the EZL and ECU of the car's temperature, whether it is starting cold or warm/hot. For the M104.980 it's a four pin and is near the water pump (it's not sensor that shows the blue pin, or the green pin on some cars). As the car is almost 40 years old, if I were you, I would replace the camshaft and the crankshaft sensor, but can be done as a DIY. The camshaft is really easy to change and it too helps with starts and ignition timing, but likely not your problem. The coolant temperature sensor is easy to replace too, but you will lose coolant from the open hole as you take the sensor out - if using a shop they shouldn't charge much to replace this. Another issue, can be faulty injectors that leak badly - you won't notice this on a cold engine as the gasoline would have time to evaporate, but you will notice it while the engine has recently run. Another part, is the fuel accumulator, and it's right next to the fuel filter, it's job is to keep the fuel pressure good and ready for a warm start - this would only cause warm start problems, and should not cause driving issues. Hopefully, this helps. Start with the CPS.

[@JOHNVASSIL]

@@HandyVal Thank you so much Val, so nice of you to share your experience with us. I have one more question please. I notice your engine was running when you checked your new CPS hot engine resistance. I checked mine was 1025 ohms while engine was hot after driving 10 minutes and removed keys from ignition. Would that make a difference?

[@HandyVal]

It wouldn’t make a difference if the car’s ignition is on or off. I think it makes sense to replace your CPS.

[@mbenz9389]

Cool! Can you please make a video(how to change fuel filter) because it’s extremely important

[@HandyVal]

Thank you. I will add to my list of future videos. I agree, it’s an important topic and will certainly be a useful DIY video.

[@mbenz9389]

@@HandyVal I’ll wait to your video then I’ll change it lol. I have already changed the steering fluid and the alternator regulator thanks to you. And saved more than $500 till now.

[@HandyVal]

@@mbenz9389 Happy to help save as much as possible, and as a bonus it's so satisfying when doing the work yourself.

[@redpig1120]

Nice car, great video

[@HandyVal]

Thank you.

[@lawsonstallings1955]

Great job!

[@HandyVal]

Thank you! I appreciate it.

[@benoitesa6292]

First thank you for this video ! I have a question for you : Can you tell me where is linked the blue/green hydraulic pipe under the ingnition sheath ? I have rebuilt my M104 and I forget only this one (We can see it at 6:34)

[@HandyVal]

Hi. Thanks for watching. I think you mean the vacuum line that has a blue stripe on it. This vacuum line goes behind the heat shield, rides along the cabin air filter and then ends where the ECU components are located. It connects into a rubber ‘V’ next to the metal box that says MAS. You need to also take out the long plastic cover around the coolant reservoir. I hope this helps. If you are on Instagram send a message and I’ll send you the picture.

[@benoitesa6292]

@@HandyVal thank you for your answer ! I will send you a message on instagram to see clearly

[@tmistah]

Cheers having the same problem with my w124

[@HandyVal]

Hopefully with the tips from the video you’ll get your car running as good as ever. Keep me posted.

[@СамвелАбрамов-ь1ш]

Hi Handy! I have one question, I have the same Mercedes as yours, same year and model, but I noticed that our cars do not have a check engine indicator, why do you think?

[@HandyVal]

It’s a very good question that I don’t have a complete answer to. All California cars had check engine lights and they were there to diagnose emissions mostly. All cars 1995 and after had the check engine, but cars prior to 95 would depend on the model. I think all 320 had them and all 600. I’ll get back to you with a better answer for all others. It’s bothering me too know. I need to know!

[@СамвелАбрамов-ь1ш]

@@HandyVal Thank you ! It would be interesting to see more of these particular models of this year, some people say that they did it deliberately and pulled out this light bulb! )

[@douglasthompson9482]

Excellent video but please use a original part not aftermarket. I just installed an aftermarket cps and it started right up. After it was warm it would not start..... I used Hella but will not use this again. The insert breaks away from the base. The original part is built much better.

[@HandyVal]

Thanks for sharing and I'm sorry to hear about your situation. I'm disappointed in Hella. They usually make good, durable parts. I hope this is a one-off and not a sign that their quality control is getting bad. Original is always best and it the safest option.

[@douglasthompson9482]

I wonder if i should disconnect the battery and try to reset the electronic system. I could also check to see if any failure codes are present.

[@HandyVal]

I think it's a good idea to reset by disconnecting the negative terminal for about 10 mins, and then reconnecting.

[@MakhosiniNcala]

hi am driving the Mercedes c230 w202, I have a problem now , if I switch on the ignition the dashboard comes on as normally but the engine not start same time as normally it just stay on nothing please help me what is wrong

[@HandyVal]

It seems like it can be a battery problem. Try testing the battery. If it’s low do not boost the car as you will likely harm your roof controller, but rather just replace the battery. You may also want to research ignition switch. As you turn the key does do you hear any sounds or is it just a dead sound?

[@MakhosiniNcala]

@@HandyVal thanks, my battery its still good, am not sure where the ignition switch, the sound i hear its a same as normal, it just turn the engine only and seems like it not receive any fuel, i di pour little bit of petrol on the throttle bottle just to test, it takes that and dead again, on my injector no petrol spray out, am not sure what is it that open the injector that's my petrol sorry for a long massage

[@HandyVal]

@ it seems like you have a problem with fuel getting to your engine. Could be a fuel pump and/or clogged fuel filter. See if fuel pump fuse and/or relay are working as intended.

[@MakhosiniNcala]

@HandyVal where feul relay and fuse located?

[@PRODSOS]

would you happen to know if a 99 sl500 uses the same part?

[@HandyVal]

Yes. The 1999 SL500 uses a crankshaft position sensor. It will look a little different than the part shown in the video. The OEM part number for the 1999 SL500 is 003 153 2828. Before buying always check with your parts store or supplier for the exact part.

[@PRODSOS]

@@HandyVal thanks for a quick response, I saw that it wouldn't be compatible but couldn't find any specific to the 99. I'll look into it thanks again

[@logandeleon5808]

Hey I have a question about my 300E w124 m104 engine, in park my car doesn’t stall at all but when I’m in drive and rev it to 2500 RPMS car kills it self, I have videos I can show if you can help, thank you, great video btw.

[@HandyVal]

Hard to diagnose, but I'll try to help. It can be a few things, but I would start with a simple check first - check your engine air filter (a very dirty filter can cause this problem, and it's a simple replacement). What if you rev the car while in Park - does it shut down?

[@logandeleon5808]

@@HandyVal I FIGURED IT OUT!!!! But yeah in park if I revved it, it did just fine, I’m drive it would go pass 2k and kill it self, but for me it was the crankshaft position sensor it was a little loose I squeezed it together and ran perfect again, somehow got loose assuming from bumps and such

[@HandyVal]

Those are the best fixes of all! Well done.

[@michaelmurray7379]

Hi Val, i have the same car as you, and i have an issue with my kickdown. It is slow in changing down, quite a long pause. I am not pushing the throttle to the floor, just wanting it to drop down one gear. Any ideas would be appreciated. Thanks.

[@HandyVal]

The kickdown requires the pedal to hit the floor and when the pedal hits the floor you should hear an audible click. The pedal backing (pedal rod attachment) makes contact with the kickdown switch. If you look behind the pedal you will see the kickdown switch (it's black and round and you're able to push it with your finger). There can be a few things wrong: 1) the kickdown switch no longer works properly (luckily it's an easy fix and cheap ($30) too - you need to peel back the carpeting and remove the switch, which is held in its spot by two clips, and is connected to an electrical wire) 2) kickdown solenoid (more expensive $75 USD) and more difficult to get to as it is attached to the transmission. Slow acceleration can also be caused by a vacuum leak. I hope this helps.

[@caleb6534]

Do you have experience replacing on a a M120? I had a rodent chew half way through my right side. Is it possible to repair the wire or does it always require a fresh harness? Appreciate it.

[@HandyVal]

That's too bad with the rodent damage. It's possible to repair and the cost may be close to a full replacement. A botched repair job is also likely. You're much better off going with a fresh harness.

[@vicana8821]

Hi Val great videos !!!. just have a question on the part number for the 300sl 24 car. my car is similar to yours. I'm having long/hard start when hot and suspecting the CPS. I can't find the exact part number that you have mentioned. all I could find is 002-153-92-28 from Hella but your part is 002-153-92-98. can you reconfirm this for us? ... I'm looking at the part from Pelican parts who have been great in the past with parts shipped all the way from the US to NZ.

[@HandyVal]

Thanks. The part number is 002-153-92-98 and I see it on the Pelican website. I too have used Pelican Parts in the past - they are good to deal with. In my video description I included two part numbers for different model cars and years. Let me know if I misunderstood anything. I hope this fixes it for you. The other culprits can be leaky injector(s) or a bad fuel accumulator.