Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
I just need to ask - is the car a manual or auto?
The car is auto.What mileage does it have?
Mileage is 82,000Do you get any fault lights on in this period at all?
NoWhat is its service history like - when was it last serviced / service due?
Last serviced in November, I have asked the garage to look at the fault but they say it does not do it for them, I have left the car over night with them but they still say it does not do it for them. The car as always been serviced regular.
This all started one cold morning a year ago. When I took the car into be serviced I told them and they told me that it did not happen when they tested it. But that they had a good look and said it could be engine mountains.so I gave them the go ahead to fit them. They fitted 2 engine mountains and a gear box mountain. the weather had warmed up and the car behaved for a while. Then one cold morning I started the car and it happened again. I made an appointment to have the car looked at but a bit of bad luck I had a heart attack the day before. I made a new appointment and left the car overnight so the could start the car cold in the morning. But I don't thin k it could have been cold enough that morning because they said it did not happen but they said that the problem could be the throttle body. They cleaned out the throttle body and said to see how it goes. This problem only happens when first starting on a cold day. The vibration only happens when my foot is on the foot brake and reverse or drive gear is engaged. The garage that I take my car to only deals with Mercedes but it is a long way and I cant always get there. that's why I am trying you.
Hello again Ray -Thank you for the extra info , that is very helpful..Given the problem only happens as you describe, it was never likely to be mountings of any sort Im afraid - but there are different reasons / causes for what you have -With the foot on the brake, this applies or takes vacuum from the engine for the servo assisted brakes - If the engine tick over rate is too low, lower than it should be, that can cause this - the shuddering etc so it needs to be first checked for any inlet air / vac leaks of any sort on or around the inlet side of the engine system - and the braking servos system. Thats the first way forward.If nothing is found there, then this goes more toward the engine temp side of things - what I mean is, when its cold its more likely to do it as the system is not right. The suspect then would be the Ect sensor - thats the engine coolant temp sensor.. This sensor sends constant temp info to the engine management computer - the computer then controls the engine fuelling etc as appropriate.. and makes adjustment for the likes of you braking etc... If the signal is wrong through a faulty sensor etc, the ecu ( computer) doesnt compensate and you can get this shuddering etc.The Ect sensor is reasonably cheap - so I would suggest replace that ( after the above ) -and see if that then cures it..Further to that - I note they have cleaned the throttle body etc - but the Idle control is overall controlled by the throttle body - On these there is a known issue with the throttle body becoming somewhat porous - listen very carefully when its doing its "thing" - see if you can hear whistling coming from that area - if there are no loose vac pipes etc, thats the issue -and the answer to that is replacement of the throttle body..IF not - then it really needs to be connected to a diag machine - not for just fault codes - but to ruin Live Data stream tests at the time its having this issue - which will then ID the fault for you..
If needed Ray, any good local garage can do the above for you --So work through as above on this one to get this sorted for you..Best Rgds, MIKE.Let me know if you need anything more on this at all - Please do click on the OK rating to Excellent ratings service for me now, Thank you for that... and you can get back to me anytime if you need / wish.. Best Rgds, MIKE. Please note, you are rating the content of my "answer" - my help to you - not the "system" which can experience delays etc which are not under my personal control -or delays caused by "time -off" which we all have on occasion - Thank you.
unable to comment because not sure if this will rectify the fault.