turbo329is wrote:
[quote]I talked to my brother last night. He is a full time BMW mechanic and part time s14 and m20 builder. He said bmw now uses castrol synthetic 10w-60 in new bmws but recommends regular gtx 10w-40 or 20w-50 in older bmws. There are no 10w-60s in the chart, but I would definitely like to see some of the numbers on it.
Sidebar: My op light came on at idle again today. I bought a really strong magnetic retriever today and fished in the oil that I drained out of it last week. There was a very small amount of extremely fine iron particles in a gray film over the magnet. This could probably be considered normal. I would cut the filter up that came with that oil but unfortunately I threw it away. I ran the new magnet over each pleat in the filter I took out yesterday again and got a lot more. Half the particles were large and brown and looked like crystals of rust. The other half was gray finely ground unrusted iron. And there were also a few large chrome looking flakes.[/quote]
What does your brother advise about all that metal in your oil? Gray film all over the magnet indicates sub 10 micron iron particles (that woun’t be trapped in the filter) are mixing with the oil and forming sludge. That is what is sucking up on the pump pick upand causin low OP. Remember also, the magnet is only going to pick up iron. There may be copper and lead (read bearings) floating around in there too,
I agree with Levie, it sounds like you are running on borrowed time. Try oil analysis next and if that shows high PPM of wear metals, it may be time toer it down beofre it tears itself down for you.
Don