BMW E30 oil pressure and oil leaks
325i
Why is the E30's oil pressure low when cold?
The cause may be dirty oil or filter. On an M20 engine, changing the oil filter and flushing the inside of the engine improved the situation, although a slightly poor cold start remained. If the pressure stays low, check the oil pump.
Where does the oil leak at the oil filter housing and oil cooler come from?
On the M20 engine the leak often comes from the O-rings of the connections. The O-ring at the oil cooler connection can fail, and the seal at the end of the valve can harden. Both are fixed by fitting a suitable new O-ring.
How is a stripped thread in the M20 oil pump fixed?
The thread can be repaired with a Heli-Coil thread insert or by cutting a new thread. An alternative is an oversize M14x1.5 thread, in which case the hole is drilled to 12.5 mm.
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