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Old 09-29-2003, 01:35 AM
suginami suginami is offline
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Join Date: Dec 2001
Location: Southern California, U.S.A.
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Quote:
Originally posted by psfred
My point exactly -- with synthetics (Mobil 1 of the appropriate grade has ALWAYS been on the MB approved/recommended list, at least since 1980), oil pressure hot should be higher than with dino oil.

My experience (and that of several professional technicians) is that full synthetics oils drain down from the tappets more slowly than dino oils. In fact, several recommend that one not check the oil level with the engine hot, only cold as much more oil stays up inside the engine hot, and there is a risk of overfilling and wasting oil.

An oil pressure gauge bouncing on the 0 peg at hot idle in an engine with low milage is a problem.

Peter
I really don't want to turn this into an oil thread.

I don't believe the synthetic oil is the cause of your MB mechanic's problem, either.

However, I've been told differently about synthetics and oil pressure. Synthetic oil is thinner than conventional oil, and slightly lower oil pressures result.

The comment about the synthetic oil draining from the tappets was based on what happened to Stu Ritter's personal 300E. His reasoning was that since synthetic oil is thinner, it bleeds right out.

Once again, this was published in the Sep. / Oct. 1997 The Star Magazine.
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2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".
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