Engine idles rough and valves make tapping noise - PeachParts Mercedes-Benz Forum

#1 05-03-2002, 10:54 AM

Hello,
Just picked up a 1985 190E (2.3 automatic with 148K) The car will start but begins to run rough immediately. There is a steady tapping noise (pretty loud) coming from the valve cover area (towards the front) I had to drive the car and noticed when I came to a stop or red light the engine would stall out if I didn't shift it to neutral (idle seems high to me) When in drive and I start to accerate, the response (pickup) is poor, Have to apply pressure slowly on the gas pedal to get up to speed.(sounds like one of those old cars you see in the movies da..da...da...da...da) The pressure gauge reads a steady 3 (all the time), while driving and temp avg between 60-80 celius, gas econony would only go into the red when accerating then would level out. If anyone can help I would really appreciate it. I read a couple articles about the OVP and coil? I guess I will start there.
PS. Is there a quick check for the fuel filter? or just replace it?

sbourg · #2 02-26-2003, 11:19 AM

First step would be inspection and checking the plugs, distributor cap and rotor, plug wires; idle circuit hoses and vacuum lines should all be inspected and replaced if cracked or loose-fitting. As far as the OVP, remove it for much of the initial testing - the car should run ok, and if it doesn't, worry first about basic mechanical operation before anything involving lambda control.

Steve

yal · #3 02-26-2003, 03:53 PM

Yep, you've got some work ahead of you, but fun work

I would take the above advise and do a thorough visual inventory and check of all that was listed.

#4 02-26-2003, 04:45 PM

While you are at it - check if the tapping only comes from one valve cover. Could be a collapsed lifter causing one cylinder to misfire. Just a thought

#5 02-27-2003, 11:04 AM

Hi,

Stalling can be a simple as a vacuum hose that leaks. Pay particular attention to the idle control valve hoses.

Dirt in a Cam Followers can cause tapping. How dirty is the oil?

Even if it's clean, try changing the oil and filter and take it for a highway drive. Does it go away for a while? If so, another oil change or two and the dirt in the Follower may be dislodged for good.

Good luck.

chicago124