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Mike, Mercedes Technician
Category: Mercedes
Satisfied Customers: 39198
Experience:  Tech Expert
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I have a Nov 2000, S55 AMG 150,000 miles. I ave just had

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I have a Nov 2000, S55 AMG 150,000 miles.
I ave just had the plugs changed and a B service.
The car now vibrates in park when started and shudders badly when driving and will not allow me to put the foot to the floor it lurches violently and will not accelerate smoothly.
If treated carefully with light acceleration it sometimes runs smoothly. When playing up it struggles to change down on hills and almost comes to a standstill.
If I stop the car and turn off the engine and restart the car it seems to clear the problem for a short time but still returns.
Can you diagnose the likely fault please and any cost effective way of resolving this please?
Hello and Welcome - My name is ***** ***** happy to help / advise.What you appear to have by your description of the faults is a misfire for some reason.As you say it now does this after the plugs were changed etc - its possible you have a duff / faulty spark plug - it does happen even with new ones... or - you have one that is not gapped properly.I would suggest then that you need to first ID the missing cylinder - to do this, have the car idling - and then you need to disconnect the wire to one plug at a time... you need to wear well insulated gloves to do this.. and have someone else do it if you have any heart issues.What you are looking for is NO change in the engine running when you pull off a plug lead... that then identifies the faulty cyliner / spark plug / circuit. So do each in turn - It should on each one cause the engine to drop / engine note change - when you pull each off. Do it one at a time - replacing the lead each time before doing the next.I dont' think you have much of a cause here - do as above to find the fault - be it a faulty plug / wire / connector / coil etc.If you dint find the issue that way, you may have a faulty injector. You can test those in the same way as the above --IF you go through all the above and not find it, you may well then need test equipment on the car to find the fault - but work through as above as the way forward.Let me know how you go..and / or let me know if you need anything further on this..~~~>>>>>>~ Meantime - Please do click on the "Exc / Ok rating" for me at this time.. Thank you in advance for that . ..Note that you can get back to me anytime at all after doing the rating - it doesn't close you out -- Best Rgds, MIKE.
Customer: replied 2 years ago.
Hi MikeThanks for this.Can be fairly sure there is not a gear/clutch issue?
Hi there.. Thank you for your reply.-- I really wouldn't have though so no-- it does seem too much of a coincidence too that it occured after the B service.. too - the symptoms do fit.. Its certainly worth going through it as above for sure.. You can always get back to me again after should you still need...=-- I hope that helps you further -- Please do click on the OK ratings for me at this point too.. I appreciate that. Best Rgds, MIKE
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