Guys,

'94 E320 sedan

After my car hit 100K miles, I have done huge services starting from Actuator, wiring harness, most of the sensors ($7K - $8K). However, my car still have this problems:

1. check engine light #3 and #26. I have O2 sensor and soleniod vacuum switch is changed. Normally, I will delete the codes after seeing them. Howwever, a month or so, one or both of them came back on. Anything else, I should look into?

2. Engine jerking! Only happen after the car has been driven for sometime and park for around 20 minutes - 30 minutes (engine cool down abit (60 degree = 80 degree)). After starting the car, in idle engine has ripple (not much) but not smooth where I can see the RPM jumbing between 600 +/- 20. Once put on gear (D or R), press on gas (car move around 2-3 mph) and release the gas pedal, the engine chirps badly!!! I started seeing this problem gradually when the car hit 85K miles and before big services. It went away for around 5K miles and now it is back to haunt me!!!

Any advice would appreciate...

 

Your engine jerking could be a couple of things. Fuel is not getting to the injectors, perhaps th fuel pump is on it last leg or the filter is firty. The FI's could be dirty also, have them professional cleaned, there is usually no reason to replace them, if you can get a professional cleaning. Could be a part spark plug. Another possibility is the pick up in the tank is not working properly. I have found over the years, cars have improved tot he point that 100K miles on a engine and major repairs are expected. I remember the days when at 50K the engine need major work. So in that aspect they have improved the durability, but they are mechanical devices and do need repairs to function. The engine on my 450SLC was rebuilt at 110K by the previos owner back in 95. I bought the car last October and it had 114K miles, so he didn't drive it much. After using 93 octane Shell and new plugs, cleaning the TB and FI's the car runs like brand new. Almost forgot, the transmission was also rebuilt at the time the engine was as well as the rear end.

All I had to do is brakes, front end alignment, and some other maintenance work. Spent about $2K. Still need to fix vacuum leaks, but these are the neverending story of these cars anyway.