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My '99 E430 with 103,000 mikes. Error. My '99 E430 with

Customer Question
My '99 E430 with...

My '99 E430 with 103,000 mikes

Mechanic's Assistant: Are you fixing your E430 yourself? What have you tried so far?

Error. My '99 E430 with 103.000 miles has a lumpy idle. My certified mechanic replaced the plugs, changed the oil, ceaned

Mechanic's Assistant: When was your last oil change?

My '99 E430 with 103,000 milse

Mechanic's Assistant: Anything else you want the mechanic to know before I connect you?

My '99 E430 with 103,000 miles has a lumpy idle, even after a certified mechanic experienced with Mercedes replaced the plugs, replaced oil-soaked ignition wires, valve cover gasket, vapor and valve covers, fuel filter, transmission filter, fuel/air induction service to include fuel tank additive, air induction cleaning to include throttle body and cylinder head valves. Fuel injector rail and top end cleaner. Even after all that, the lumpy idle, although lessened, still remains, especially during a cold start at 1,500 rpm, to 500 rpm at idle. What next? Thank you,

Submitted: 5 months ago.Category: Mercedes
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Answered in 28 minutes by:
3/16/2018
Mercedes Mechanic: Marty, Mercedes Technician replied 5 months ago
Marty
Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 55,280
Experience: Bosch Certified Master Tech. Over 35 years experience.
Verified
Hi, my name is***** other possibilities to consider would be uneven engine compression or one or more bad ignition coil’s or a fault with the fuel mixture. I would recommend a compression test to check for even compression on all cylinders and a smoke test of the intake system to check for any intake leaks. If his scan tool is capable of running a smooth running test it would help to identify the weak cylinders. Once you have identified the weaker cylinders you can swap ignition coils and fuel injectors around to see if anything changes.
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