2003 Mercedes CLK 430 problems

FoDaddy
Tue, 29 Jan 2013 03:57:05 +0000
Maintenance/Repairs

My mom just picked up a CLK 430. I drove it around for a bit and noticed that a few things didn’t seem quite right

1. The transmission seems to start out in 2nd gear rather than first even when the transmission is not in “winter” mode. The transmission is also very hesitant to downshift, and often times will not downshift at all if the car is moving.

2. There’s a noticeable amount of lag time between when you stand on the gas and when car actually starts accelerating.

3. The engine doesn’t seem to rev very quickly or freely, and there is some noticeable pinging when the engine is under load. Performance was very tepid for a 275 HP car.

The spark plugs and ignition wires were replaced last week. The car has 105k miles on it. I know the previous owner used regular unleaded, and the owners specifically states that 91 octane should be used and goes as far as to mention precautions that should be taken should regular unleaded. The car was filled up with 93 octane fuel earlier today.

Just 15 minutes ago, I took my stepdad out in the car to demonstrate my findings. On the first drive (about 5-10 minutes) the car acted like it did when I had driven it earlier in the day (not downshifting, hesitating, lack of power, etc.), and the check engine light came on. He wanted to drive the car to see for himself. So we pulled over, shut off the engine and switched seats. He got behind the wheel, started the car, the check engine light is still on. But the car ran perfectly. It was starting out from 1st gear and would downshift promptly when give full throttle. Performance was immensely improved. The check engine light is still on though. The car has a 1 year bumper to bumper warranty. So I guess they can bring it in to have it looked at.

I’m just sort of at a loss as to why the car performed so poorly when I drove it, and all of a sudden performed correctly, after the engine was restarted. Anybody have any ideas about what happened?

24 posts - 9 participants