I picked up a spare engine for my 850 some time ago. It came out of a wrecked car with only 64K mi. A nasty front end collision on passenger side. Engine sustained some minor damage, the full extent of which I am still uncovering. Engine/transmission mounts tore apart and everything was pushed back in chassis a bit. Passenger side distributor took a knock.
Anyhow I did a leak down test on it today, the first time I have ever done this and would welcome comments from those more experienced. I ran the test at 60psi (a little over mid scale on my tester).
Results are in the pic below
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Most all cylinders had some leakage into the crank case. By wiggling the crankshaft I could often improve this leading me to believe the rings are a bit sticky (engine is cold and not run in at least 18 months). Normal?
2 cylinders had noticeable leakage at the intake valve but sometimes sealed. None of the exhaust valves had any leakage. Many of the intake valves have some carbon build up on them and same on the pistons too (why are these engines so dirty). Perhaps this is the cause of the intake leak.
Leak down results were best with the piston exactly at TDC. Just a very small amount either side of TDC (valves are still closed) there was noticeably more leakage past the rings into crankcase. Why is this?
Damage so far...
SE16.JPG
rotor hit the distributor and sheared the pin on the hub!
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engine2.JPG
I found some pleasant surprises too... like a brand new set of BMW intake manifold adapters that must have been installed just prior to the accident, still nice and soft with raised sealing ridges march 2015 date code and a new water pump/thermostat.
Last edited by BMSman; 08-21-2017 at 01:26 AM.
These are such pretty engines, in and out of the car IMO
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