Noise on startup....

[AAPete]

When starting my car in the mornings, it sounds like a blow on the exhaust, anyone else get this? I have had the exhaust checked all OK, once the car heats up the blowing goes away..
Any ideas?
CLK Kompressor

 

[190]

Check exhaust manifold for tightness and cracks on the manifold, also check the flange gasket.

 

[AAPete]

The car is still under warantee and the Mercedes dealer cant see a problem?
I think there is a slight hole that is filled once the engine is heated up...

 

[piestore]

sec air injection

Hi

what you are hearing is the secondary air injection system, it sounds very like a blowing exhaust, as a test open the bonnet and start the car (from cold) and stand next to the engine you should hear the secondary air switch of after a minute or so, I should say that i have seen some split manifolds on the 111 and 271 engines but this is rare

 

[stwat]

It does sound like a gasket. The only way for them to recreate the problem, is for them to have the car over night in the workshop and then start it from cold in the morning, just as you do when you hear the blowing. The only problem is getting them to agree to do this!!!!!!!

Put your size nine down and tell them to take the car in overnight because it only happens when the car is stone cold first thing in the morning.

I have had the very same prob on VW Golf GTI in the past, so i know what your on about. As soon as the car was up to temp it didnt blow all day. It was only when the car had been stood overnight that it blowed. The dealer just didnt want to know so i parked the car in their carpark the night before it was booked in and turned up with the keys first thing next morning. I made sure i got the head mech out before i started it and when i did, sure enough, he said the manifold gasket was blowing and needed replaceing. That was the third time the car had been back for the same prob!!!!!!!!!!!!!!!!!!! And i was told that the gasket had been replaced on the first visit!!!!

The thing that gets me is that they lied when they told me they had replaced the manifold gasket!!! And it needed me to to be almost forcefull just to get a simple fix done!!!!!!

Just imagine if it wasnt under waranty and i wasnt a difficault bastard. The amount of people that get fleased every year makes me sick!!

oh, and by the way, i was in the motor trade for 8 years before i managed to get out!! Its a very nasty place to be. Even the big dealers are con mearchents i promise you.