My M42 Sounds like a Diesel? Oil light flashing?

[E30Kills]

I was recently driving my E30 when I began to notice the oil light on the dashboard flashing every couple minutes or so. I pulled over to check the oil levels and they at the full level so I just kept driving to get to my destination. On the way home the oil light began to flash more often and my car began to sound like a diesel engine. I should have pulled over but I said screw it and drive the rest of the way home. The car also made a distinct ticking noise before this happened.

Recently I have replaced the valve cover gasket to fix an oil leak, and put in new Bosch iridium sparkplugs. Also, I had to mix some synthetic lower viscosity oil with the non synth, high visc oil in order to get home because I replaced the valve cover gaskets two days before due to an oil leak and had no way of getting other oil to put in where I was.

So here is the list,
-I mixed oil visc and synth with non synth
-I put in new sparks
-I just changed the valve cover gasket two days ago due to an oil leak
-Now the oil light is flashing and my car sounds like a diesel even though it has full oil

Time to do a swap?   

[romkasponka]

Check your sump. Very big probability you will find lots of loose bolts if the sound is from hydraulic compensators.

http://bmwfans.info/parts-catalog/E30-2-doors/Europe/318is-M42/L-M/jan1990/browse/engine/oil_pan_dipstick/
Remove lower part and check all the bolts which attach upper part to the cylinder block.

also check bolts Nr1. http://bmwfans.info/parts-catalog/E30-2-doors/Europe/318is-M42/L-M/jan1990/browse/engine/lubrication_system_oil_pump_with_drive/

If you will find metal chips in the oil filter or oil pan you will have to rebuild or change engine. That was bad decision to drive with low oil pressure light illuminated.

[E30Kills]

So I've basically screwed my engine over at this point would it be more cost effective to rebuild it or do an m20 swap?

Check your sump. Very big probability you will find lots of loose bolts if the sound is from hydraulic compensators.

http://bmwfans.info/parts-catalog/E30-2-doors/Europe/318is-M42/L-M/jan1990/browse/engine/oil_pan_dipstick/
Remove lower part and check all the bolts which attach upper part to the cylinder block.

also check bolts Nr1. http://bmwfans.info/parts-catalog/E30-2-doors/Europe/318is-M42/L-M/jan1990/browse/engine/lubrication_system_oil_pump_with_drive/

If you will find metal chips in the oil filter or oil pan you will have to rebuild or change engine. That was bad decision to drive with low oil pressure light illuminated.

[DesktopDave]

A good rebuild can cost a lot, especially given oil starvation. Lots of bearing surfaces need to be checked out. I'd look for a used M42 from an early E36 with a manual tranny. They're common and pretty cheap. Earlier model M42 (<'93?) swap right in, with a few of the E30 parts. Later models of the M42 ('93-'96) need a bit more work, but can still be used if you swap over a few more parts from the E30 motor. IIRC you need the oil pans, motor mounts & arms, intake manifold and the correct belt drive system. The E30 computer is simpler, has none of that Bosch EWS business, and the E30 harness will run a later M42 with a few sensor & wiring tweaks.

An M20 swap would work out too - those motors are still pretty common. Be aware that the E30 M42 & gearbox (Getrag 240) are angled differently than the M20 & Getrag 260 combo. A few guys on here have used the tougher Getrag 260, just bent or welded the shifter arms & tranny subframe to compensate. The M20 flywheel is lighter than the M42 version. Be sure you get the late model FW too (after mid '87 production date?). The ring gear on earlier E30s has a different tooth pitch, and the late starter won't work with it.

[romkasponka]

In case engine is dead I would not look at anything older and less powerfull han M50b25. In case you want serious power I would go for S54.