What in the world is wrong with my '94 C280? - PeachParts Mercedes-Benz Forum

brookspw · #1 08-07-2009, 03:31 PM

I have two issues right now (well, my car does, anyway):

1. Idle surging
2. Rough ride / feels like front wheels out of balance.

Problem 1 / Idle Surging -- Had head gasket replaced in March. R/R cracked the wiring completely on the old EA/actuator. Replaced it with one from a salvage car, a 96. Code gave us the air flow meter -- got an aftermarket one. Seemed like all was well. Then, it started surging at idle. 600 to 1,100, but would run fine when driving. Lately, surge got worse, engine is rougher driving, and I get real rich type exhaust at idle and MPG is down 5 mpg. Reading http://www.peachparts.com/shopforum/showthread.php?t=194257 gave me the idea to spray soapy water at intake gasket, hoses, etc. I found no leak. I also tried to check the purge valve. Felt no pulsing. Tried to "jiggle" it and somewhat dislodged it and snapped it back.
-- NOW IT RUNS GREAT. Well, sometimes I get a "tiny" bit of idle fluctuation but otherwise it is smooth as silk.
-- Coincidence? -- Soapy water temporarily plug a pinhole leak? -- Did "jiggling" the purge valve help?

Problem 2-- In March, had tie rods, ball joints, steering damper, etc. replaced and got fresh alignment, rotate and balance on good tires.
-- New brakes, new rotors.
-- A month ago the road noise began to build. Replaced wheel bearings thinking that was it. Nope. Mechanic said it was the tires that needed an alignment and were wearing unevenly.
-- Yesterday, I got get an alignment. I am 100% in spec -- completely aligned although the front tires did show odd wear. Rotated front to back and rebalanced on Hunter 9700.
-- Shocks seem to be working just fine. They were replaced 30k ago and car immediately settles on the rebound, no bouncing at all.
-- Road noise is a little better but not gone.
-- Out of balance shimmy is still there, especially 75-80 mph.

What is your take on either situation?