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xtracooljustin
01-16-2007, 02:20 AM
Hi there.

Im running on a 1994 E34 525i VANOS 4 speed auto thats has covered 210k KMS. Had the car not more than 4 months plus.

Having not use the car for about one whole day, I find the car vibrates very badly even at idling. Vibration continues on especially from standstill to 2000RPM. Car is reluctant to accelerate at this range and after 2000 RPM acceleration becomes smoother. Vibration becomes less til it completely vanishes. Exhaust is extra rich and economy is very bad, as seen from economy gauge esp from standstill to 2000 RPM or before 60km/h. During this acceleration, Im getting no less than 20L/100KM sometimes beyond 30L/100KM at the economy gauge until i take my foot off the accelerator pedal. Vibration is less when my foot is not on the accelerator pedal. Sometimes at 80km/h even at 3500RPM gearbox doesnt upshifts. I travel a short distance from home to university (about 2kms) so rarely have the chance to take it beyond 80km/h, but it I did, the process is painfully slow, full of vibration and very not economical. Even revving at standstill, its very difficult to rev the engine from idle to about 2000RPM (get heavy vibration and juddering that can be felt throughout the car, with the exhaust feels like coughing literally) and gets smoother after that range.

A visit to a mechanic around my area said it could be water leaking into the engine. Taking off the engine cover and checking the electrical points, he says strangely there are no traces of water. After that he hooked my car up with the diagnostic kit and the diagnostic kit did not turn up any fault codes watsoever. He also checked for any loose vacuum hoses but couldnt find any leakages. He also adds that the only reason would be the spark plugs but that would require him opening up the engine which Im reluctant to until I get a second opinion.

I've checked the archives and have done the search but not any vibration case mentioned here is identical to mine. For your information, it has been raining non stop here for the last 3 days, ranging from continous light drizzles to heavy downpours, resulting in floods in nearby areas. Although my car and I are not affected, I think this cold and wet weather could have played a part in the problem thats plaguing my car.

I'm taking my car to another mechanic to get a second opinion tomorrow but would like to know if anybody experienced this problem before. A close fren of mine who owned a E34 before experienced something similar and he told me its something to do with the air mass sensor, although this has been proved wrong by the diagnostic kit.

Any advise or help is greatly appreciated. Many thanks in advance.

BillionPa
01-16-2007, 03:11 AM
you change the engine and transmission mounts yet?

if not, do that, and make sure all the bolts are tight.

another thing to consider is a leaky injector, which would cause uneven power one of the cylinders, kill fuel economy, and cause the engine to vibrate due to uneven pressure on the crankshaft.

632 Regal
01-16-2007, 05:27 AM
search for "missing" not vibration. could be a bad coil or wire, oil around the spark plug will cause the same problem with a risk of ruining the DME from a short.