impr

Hi guys,

My cousin recently purchased a '97 c36 amg, and almost a day after driving it off the lot, he's encountered some strange stuttering issues.

Generally the car drives fine, but after about 30 minutes of driving, the vehicle starts stuttering and jerking wildly, making strange noises. Additionally it can only hit speeds of about 20kph or about 15mph.

He tried pulling over to the curb turning off the car and restarting it, which worked for a while but after a few minutes the problem reoccurred. Apparently when driving back home at night however it was fine.


I've searched the forums extensively and have come up with a plethora of potential causes, but if anyone else has experienced this and successfully fixed the problem, it would be of great help.


Since its a '97 I hope its not a head gasket issue or a wiring harness issue. I'm hoping it could be something like the sparkplugs, MAF, or fuel pump/injectors.

Thanks in advance for any help you guys can provide.

AMS Performance

If its head gasket the car will still run normally but you will get mixture of oil in coolant, or get steam coming out of the tail pipes (and eventually overheat). If you aren't over heating then that is most likely not the issue. Usually, the symptoms you are describing are more electric related, (could be harness or parts of the ignition system). hope that helps.

impr

Thanks for the input AMS is there any quick way to visually check the wiring harness?

MarcusF

Aside from the insulation being cracked all over, open the hood at night. If you see a light show, turn it off and order a harness.

impr

Hi guys,

Went and checked the car tonight, had to replace the battery since the one it came with was completely dead.

After getting that to work, found that the car was too low so the tires kept rubbing, but that wasn't the stuttering issue.

Anyway, the car drives fine in non stop and go situations. Drove it for around 40 minutes and the thing felt fine. But then we decided to try and simulate a traffic situation.

So we proceeded to stop and go every 7-10 feet. Stopping for a few minutes at a time then going again, which rose the engine temp from around 85 to about 90-95. After doing this, we attempted to accelerate to a normal speed. As soon as we hit 2500 rpm the car would stutter violently with the tach pinging off the 3000rpm point and not going above that.

The car could still shift up through the gears fine, as long as you stayed below 2500rpm. After about 5-10 minutes of just straight driving without stopping, the car cool down back to about 85 and it could easily rev past 2500 rpm again.


Oh and checked all the wiring in the engine bay, everything seems fine, no cracked wiring insulation or anything near to those nightmarish pics of the 500e faulty wiring harness.

Could this be a problem with the MAF?

Thanks in advance for any help.