Jimmy Chen Shib

Thought if any of you have clues or solutions to my problem: the car is a 1994 E60 with around 88k km. I am the second owner. Lately, this fibrillation-like, intermittent shaking during idle has bothered me.

I do not profess to be a mechanic minded and the shop and I decided to replace the ETA, electronic throttle actuator. I do see some improvement, but the symptom is not totally resolved. Last week, the car was smooth as silk, yet few days later, the problem surfaces. I only drive her about once a week, since I have to keep other cars happy.

Thought I would ask the experts out here to see if anyone can give me an answer or direct me to the source of this annoying prolblem.

A bit baffled. Thanx in advance.

w/ smiles

Jimmy

Quicksilver500

Jimmy,

You should post this on this site http://www.500eboard.com/forums/forum.php

Its possible when they replaced the ETA the bumped a vacuum hose, or something like that. It may not hurt to check the condition of the upper engine harness as if it is original it will cause problems as it decays.

Does the shaking occur at all times, just at cold start, or when hot? If its all the time and only at idle I would take a quick look at the ignition components. Its not uncommon for rotors, plugs, wires, to be worn out on m119 cars. Plugs every 15k or less and caps/rotors every 30k or less. If you keep those things in good shape the wired will last longer, but will eventually develop white burn spots where the insulation is degrading so you can look for those too.

-Mike

ptoro01

Yup sounds like a vacuum leak, were the hoses going to the lower part of throttle body replaced?

Jimmy Chen Shib

Comments appreciated, Mike and ptoro01.

The fibrillation has been there for many months, however, intermittent. Sometimes there and non at all otherwise. Only at idling or waiting red light with brakes on. It is not consistent and unpredictable.

The ETA was replaced couple weeks back and I have only driven E60 few times since. At least I can say that the symptom is less serious or noticeable since the replacement of ETA. Nevertheless, it is not eradicated.

I would relay the suggestions with my shop. Thanx again.

w/ smiles

Jimmy

Jimmy Chen Shib

So, after many years of trouble with the "fibrillation" issue, the problem's cause has been identified and resolved. Prior to this, we have looked at all the known potential causes with intermittent improvements but never seemed to be sure of the real trouble source. Among the remedies done, recently we replaced the two distributors with new Bosch ones also.

Fast forward, soon again, the car seemed to experience the same symptoms. Thus, the suspect was the distributor caps. The culprit was the internal surface material that was prone to moisture trap resulting in irregular firings. The solution was to multiple coat the internal surfaces of the two distributor caps to prevent moisture condensation, very simple job, and the car now runs smooth as new without the annoying intermittent, irregular shakes.

Therefore, the problem had to do with the quality of the parts. My friend who owns the shop said that much of the modern parts have suffered in quality and this was one of those. In his words, Bosch supplied distributor caps used to have better finish that did not make them prone to condensation traps.

Hope this information would be of help to others with similar issues.