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billjam billjam is offline
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Join Date: Aug 2007
Location: Perth, Western Australia
Posts: 2,003
Black granules in my oil !!! Help!

I have just done my first oil change 400km after a rebuild (which included new bearings, valve guides and camshafts, but same pistons, rings and barrels and a K27...11.11...7200 turbo).

I drained the oil into three containers and as I was emptying them I noticed little black granules in the oil from the oil tank and the turbo tank. There must have been twenty or thirty of them altogether.
They are really hard and shatter into little pieces when hit with something hard.

My car usually does short trips (7 minutes) each day to work and back with a few longer runs ocassionally. Daytime temperatures in Perth for the last couple of months have been between 30 to 40*C (85 to 105*F) but the car doesn't run hot (just above half way on the temp gauge). I have also opened up the rear bumper and deleted the valance to keep temperatures a bit lower around the turbo. Gotta stick a pic of this cos I reckon it looks good.

I am using Shell Helix fully synthetic 5W-40 oil. There may be a few oil tragics out there who might be interested so here's the label.

I have heard of coking in turbos before, so I presume that's what I have here. My real concern is about having this stuff floating around my oil system. It definitely must pass through the scavenge pump to the oil tank; I just hope that's where it stays.
Is this a common problem in hot climates or is it more to do with the type of oil I am using?

And I guess the $64,000 question is - what should I be doing to avoid creating more of this? Change oil? Drive the Toyota to work?
1988 Carrera - 3.6 engine (with ITBs, COPs, MS3X) and a whole set of turbo body panels waiting in the attic.
Day job ...
Memories: '68 912, '72 911T, '80 911SC, '84 911, '85 930, '86 930, '87 911
Old 02-20-2009, 11:51 PM
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