w202mylove

Hello guys,

I got another problem with my c36 today. I am starting to feel a little embarrassed for my car She hasn't been very reliable for me. I'm not mad at the car but I am starting to run out of money.

Today my friend his girlfiend asked me to bring her to work because her car broke down. So far so good. After I parked the car and made sure she got safe to work I got back in the car and fired it up. The rpms started to jump up and down, my immediate reaction was: what the h*ll is this I gave her some small revs to stop the jumping. I drove away and the car started to hesitate during acceleration(jumping forward and backwards). then suddenly the problem stoped and came back after a few miles.
When I arrived at my friends house I disconected the MAS air flow sensor the problem was still there. I went back inside a bit dissapointed in my car.
In the evening after the car cooled down I decided to go home from my friends house. Car drove perfectly normal.

Tomorrow a friend will read the codes out so I know some more. I will post these tomorrow.

What could be the problem? I need to mention that I replaced all the sparks 6k ago. Replaced all the fluids 1.5k ago. And replaced all three the coils 500 miles ago. Besides that I never use the car in winter and I completly baby her. last weekend I went on a road trip through Germany. The car performed very good! I felt so happy afterwards because I had more problems in the past with it.

The things I suspect are the MAS air flow sensor and the 02 sensors.
I suspect the sensors because two weeks ago I had to replace all three of the distributor coils. I had to drive about 15 miles to the shop on 4 cylinders this could have been bad for the 02 sensors.


Maybe there is someone who has experienced a similar situation that could help me with my problem. I appreciate all help !

cm60k

Any chance to diagnose the car, before throwing $$$...

ZAYED,,

w202mylove

I will get it diagnosed tomorrow and post the codes later! I dont really know how usefull these codes are to diagnose the problem exactly that is why I posted this topic in advance.

cm60k

I see,

i believe codes will help where can we focus, fuel vs air....

ZAYED,,

w202mylove

I really hope this hasn't got anything to do with the wiring harness. My mechanic always tells me the harness is good, really hope he is right on this. Litterly everything that can go bad on a c36 has died on me not trying to sound negative but... lol will this end somewhere.

jajohnston1

I had a very similar issue, here is my video on what mine was doing: . If this is what it does then it is in fact the Mass air flow sensor. I had replaced it over a year ago due to the check engine light coming on all the time and it always read the same code. I stupidly replaced it with an aftermarket one instead of a BOSCH(OEM) brand one. After i replaced the MAF with a BOSCH brand it fixed all the issues. Hopefully that helps you out. Oh and BTW buy the whole MAF not just the sensor.

w202mylove

Thankyou very much for the information! Did your car drive normal besides the described problem? As I can tell from people's story about broken MAF sensors I think people experience different problems from this problem. So this could be the reason for my experience being a little different. Although my rpms jump like that, difference is sometimes it does this and sometimes it doesnt. I hope I have more information later this day!

cm60k

Yeah, MAF is a genie, did you replace it recently..??

ZAYED,,

w202mylove

No I did not, for 90% i'm sure it is a typical broken maf sensor. If it would have been the 02 sensors I think the check engine light would have came on.

cm60k

In any case, replacing the MAF, is good idea for more perform, replace it first & see what will comes-up...

ZAYED,,

w202mylove

Thanks, I will order one from bosch today. How do I let it adapt in properly ? After install I need to run the engine sationairy for a few minutes ? Or do I drive it immediately?

cm60k

MAF is plug & play, no any adapt., after install it, just need to delete the MAF code from the ECU memory..

ZAYED,,

DRBC43AMG

Correct, get the code erased from the memory and you are good to go

Super B

You hadn't mentioned the year of your car. But if it's a 97 you can unscrew the security bolts and slide the maf out of the housing. On the side of the maf sensor you will see the Bosch part number. It's been years ago so I don't remember now. But if you search for that sensor it was used in a couple different cars. If I remember right one of them was a VW and it saved some money on the price of the sensor and you were able to buy it separately from housing saving a little more loot.

cm60k

It's 96, mentioned in his profile..,,

Super B is correct about 2 screws, pull them-out, instead of remove a complete housing..

ZAYED,,

w202mylove

Thanks guys, just came back from the shop. For 99% he is sure it is the sensor. I will order the part right now.
My car is a 96 indeed.
jajohnston1 above here in this topic advised me to order the complete MAF. Just to be sure I will order it like this. I can get the part for a little under 200 euro on ebay which is a lot cheaper than from the stealership. Downside is that I have to wait a few days But im happy to wait if I can save some cash. Thanks for the help guys I will post if the problem is fixed next week!

jajohnston1

Just make sure it is a BOSCH, if it is not OEM you will have other issues show up. Plus i noticed that once I went back to a BOSCH i saw a performance boost to what it was with the aftermarket generic one.

w202mylove

I ordered the BOSCH one! (part:028021750). Since it is an important part I want to be sure of using a good quality brand

RPB

Definitely sounds like the MAF, just clean the old one for the time being. Had the same issue on mine around 112k miles. You were very smart by getting the genuine Bosch unit!!

GL.

w202mylove

Just got the part in, problem is solved Very happy thanks for the help guys!

cm60k

Glad that NIGHTMARE gone...

ZAYED,,

w202mylove

Guys I have another question. car runs fine but idle isn't perfect it surges a little nothing to crazy but it is strange(car did not do this before). Can this have anything to do with old faultcodes is the system? btw the euro c36 had no check engine light!

cm60k

As i know; Euro/Japan spec. didn't have check light, only U.S version,

cause got "2" O2 sensors, while U.S got "4",,

*try to reset the ECU, or disconnect the battery for atleast "2" hours...!

ZAYED,,

w202mylove

I will do that tomorrow. And soon I will go to the shop to clear the codes, if I understand it correctly they stay in the system untill they are being cleared. Is that right?

Super B

Yup like zayed said you can clear out the trims and ecu.. Or just not worry about it and the car will adapt over time. Never hurts to do a vacuum check and see where your at either.