Cyclistposer

I took out the C63 on the track in mid March this year. Everything went well except some of the gear shifts started oddly hanging from 2-3. Then I took the car out today and later in the 2nd session the gear shifting started to hang from 2-3, 3-4 and 4-5. Then in the 3rd session the shifting kept hanging big time and then I started loosing all power. When I pushed on the accelerator, nothing would happen. Oil temp was about 271 and transmission was 199 degrees.

Not sure why the loss of power and when I think about it, the power from the engine has not been the same since before I first took it out on the track in mid March.

Thoughts?

abcut973

Limp mode probably. Pretty common on MCT cars.
What do you mean transmission 199? Where did you measure it?

Cyclistposer

Meant coolant temp not transmission. Looking into the limp mode in the forum. Thanks for the guidance!

izzy63

its probably limp mode, my car did the same every 2-3 laps at big willow

Wobble64

Look up my post on engine oil cooling upgrade, there is a lot if info in there.

Also you can track transmission oil temp via an OBDII dongle and phone apps like Torque.

Hope this helps.

BLKROKT

Try this if you're not ready to commit to the cooling upgrade. Will prevent limp-mode altogether.

https://mbworld.org/forums/c63-amg-w...your-cool.html

Case1906

Welcome to limp mode....

zcct04

It's not this. Limp mode is a temporary ECU status designed to protect the drive train from a perceived problem. It goes away as soon as the problem is no longer detected and the ECU is recycled (car is restarted). If OP has been having low power problems since his track days, then he's got something quite different from limp mode.

abcut973

How can you be so sure?
There is not enough info from OP to be 100% affirmative it is limp mode or not. But the little information he gave makes most of us think it is a limp mode situation.
The question we have for OP is: between runs when the car cooled off did the power come back? And was the power loss only happening during session with high oil temperatures?
Also you might have 2 separate problems (transmission and power loss). The gear shift hesitation might have triggered the limp mode. Maybe try a TCU reset
Do you have a ECU tune?

yeswife

Ummmm what's limp mode ?? Lol

Cyclistposer

I dropped the car off with the Mercedes dealer and after their review, they said it was probably limp mode. Just to be safe and they were happy to do it , I had them change the oil and transmission fluid. The AMG technician said everything else checked out. So we will see. Hoping to take it back to Road Atlanta June 14th...

Between runs when the car cooled off the power came back, but not for that long. I warmed it up in the first 2 laps of that session and by the 3rd it was back in limp mode. The power loss only happened during session with high oil temperatures and typcaly something was acting up (gears hanging or limp mode kicking in) by lap 3. I'll look at a TCU reset and I do not have a ECU tune...

I appreciate the guidance & help!

BTW, I was reading the posts on Keeping Your Cool!! and then they just stopped. Did something happen to AutoTech Racing???

zcct04

I stand corrected.

OP: the car will retard timing (which cuts power) once the engine oil temp hits 278F. Timing - and power - both come back as soon as the temp drops a couple degrees. Shifting to C or just a slightly allowing your pace for 20-30 seconds is enough to do it. The 'keep your cool' thread has a couple of solutions to help fix this.
I've not had the tranny problems you described - can't help you on that one, but it's probably more of the same heat issue.