Quote:
Originally Posted by jetfiremuck
Only other option is to drain and refill with non synthetic and try that. Its bizzare that if the engine is anything other than flat that this problem can manifest itself. I m aware of the long run to the oil pump from the pickup.
Would a new oil pump with tighter clearances help?
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I don't think synthetic oil vs non-synthetic would make any difference, all else equal. The viscosity of the oil is the real factor, I would guess.
What about switching to a lighter weight oil along with the correct spec type filter? A 5W30 or 5W40 oil is what I would expect to give the biggest difference in length of time to build pressure. Even in Florida, 15W40 oil is very thick first thing in the morning, synthetic or not.
15W40 is good for diesel pickups and semis, but I don't think it really has any place in our small high speed automotive diesels. One time I had a tired AHU TDI that I was trying to cheap out on the maintenance, and used some 15W40 dino oil I had in it. It developed a terrible rap and miss that would occur if I was trying to accelerate above about 3000 rpm before the engine was fully warmed up. I switched back to 0W40 and the problem went away. I suspect what happened was the hydraulic lifters were pumping up too much (or couldn't bleed off pressure fast enough) with the too thick oil when cold, and they were holding some valves open when the revs got too high. Felt and sounded scary when it happened, like the engine was about to put a rod through the block, big popping noises in the intake manifold. That taught me that these lightweight engines really don't like heavy truck oil!