Recently purchased an e92 335i with blown stock turbos to start my build.
I started by pulling the motor, removed the turbos and the rest of the accessories. I saw that at some point this motor may have ate a belt...There was belt debris under the power steering pump, ac compressor and a VTT seal guard was installed (I'm assuming too late).
I planned on doing rod bearings in prep for big boost, so during that process, checked the oil pump and pick up tube for belt debris - All was clean including no abnormal bearing wear for 90k mileage.
Also tried to check the cylinder walls the best I could for scoring or damage - checked out ok.
While doing a walnut blasting (all of the intake ports were coated in oil/ gunk which was expected from the blow turbos drinking oil)
I saw that cylinder 5 exhaust port is full of oil while 1,2,3,4 and 6 are completely dry. When looking into cylinder 5 spark plug hole I see oil.
My question is does that automatically mean I have a bad oil/piston ring?
I'm assuming a compression test would give me an answer? any other ways to test?
Thanks for reading!
I started by pulling the motor, removed the turbos and the rest of the accessories. I saw that at some point this motor may have ate a belt...There was belt debris under the power steering pump, ac compressor and a VTT seal guard was installed (I'm assuming too late).
I planned on doing rod bearings in prep for big boost, so during that process, checked the oil pump and pick up tube for belt debris - All was clean including no abnormal bearing wear for 90k mileage.
Also tried to check the cylinder walls the best I could for scoring or damage - checked out ok.
While doing a walnut blasting (all of the intake ports were coated in oil/ gunk which was expected from the blow turbos drinking oil)
I saw that cylinder 5 exhaust port is full of oil while 1,2,3,4 and 6 are completely dry. When looking into cylinder 5 spark plug hole I see oil.
My question is does that automatically mean I have a bad oil/piston ring?
I'm assuming a compression test would give me an answer? any other ways to test?
Thanks for reading!
Last edited: