M42 running VERY loud (video), low oil pressure light is on

[kwill22]

Aw man I thought you were saying you got it running then I realized the quotation marks. Lol but yea sounds like what I was saying about the air being in the system between the oil pump and pickup.

I don't know what kind of external pump he used but sounds interesting. I'm assuming just a regular external hydro oil pump but I don't know how he would've ran it. I don't see anyone building 50 psi by hand. Shoot him a pm

[Vivek]

I can't recall...did you rebuild the bottom end or anything and put assembly grease in there, or is the only lubrication going to be whatever film of oil was left from last time it ran properly?

I'm not sure if you can get away with pulling caps and reusing everything. I want to say yes, but maybe someone that has built more engines can chime in there.

I am sure that there is a bit of premature wear at least somewhere in the system. I bet it's safe to say that the rings are "fully seated" at this point.

This whole thing still has me scratching my head. I've never seen a case where the pump was this tough to prime, but it sounds like others have. I just cannot see how the oil pump crapped out if it was running properly before you bought the engine.

Nope I never touched the bottom, head, or any internals :/.

http://www.r3vlimited.com/board/showthread.php?t=314343

"I had my machinist come over today and he brought an external pump (oil) which we used to back flow the engine through the filterhousing. The system with car off held a rock solid 50 PSI throughout the fill. Once finished we reconnected the oil pressure tester and got the above results. It appears that I had air in the system (good call TobyB and Phil, BTW) which was forced out by the back pressure. Car is running normally now."

What's an external pump, and how do I get/use one? This may be my issue.

[golde30]

This is a strange scenario. My s52 sat for 10 years without an oil pan, it was bone dry before i fired it up and never had a pressure issue, but I also poured a cap of marvel mystery oil into each cylinder through spark plug hole before firing the first time. took almost 8qt before the oil level was rite. Book says capacity is 7qt.

[bmwm42]

http://www.r3vlimited.com/board/showthread.php?t=314343

[bmwman91]

I can't recall...did you rebuild the bottom end or anything and put assembly grease in there, or is the only lubrication going to be whatever film of oil was left from last time it ran properly?

I'm not sure if you can get away with pulling caps and reusing everything. I want to say yes, but maybe someone that has built more engines can chime in there.

I am sure that there is a bit of premature wear at least somewhere in the system. I bet it's safe to say that the rings are "fully seated" at this point.

This whole thing still has me scratching my head. I've never seen a case where the pump was this tough to prime, but it sounds like others have. I just cannot see how the oil pump crapped out if it was running properly before you bought the engine.

[Vivek]

No way $2500. I say you could do it for under $1k if you reuse your current flywheel->diff and just changing the motor with an m50.

You know anyone currently selling what I need? If I can find what I need for a reliable and bar-able swap for $1k I'd definitely do it.

This thread is taking an interesting turn. Might be for the best, too.

Vivek, I am local and if you want to try to tear into the timing case to see what might be up with the oil pump I can lend a hand sometime. I also made a crank locking tool for breaking that big ass crank damper bolt loose, and you are welcome to borrow it. Your engine might (MIGHT) still be OK since it has not run too much, and it's probably worth spending a couple more hours to see what exactly went wrong. Still, M50 for $1k is a pretty sweet sounding deal.

Steven and I may try to go ahead and do this in the coming week, so I'll probably take you up on that offer. To check the bearings, would it be okay to just pull a bearing cap and inspect it, then torque to spec? Do you think this could have worn my rings or anything in the top end?

[bmwm42]

You can replace the oil pump without removing the engine done it many times about 6 hrs tops

[bmwman91]

This thread is taking an interesting turn. Might be for the best, too.

Vivek, I am local and if you want to try to tear into the timing case to see what might be up with the oil pump I can lend a hand sometime. I also made a crank locking tool for breaking that big ass crank damper bolt loose, and you are welcome to borrow it. Your engine might (MIGHT) still be OK since it has not run too much, and it's probably worth spending a couple more hours to see what exactly went wrong. Still, M50 for $1k is a pretty sweet sounding deal.

[golde30]

No way $2500. I say you could do it for under $1k if you reuse your current flywheel->diff and just changing the motor with an m50.

[Vivek]

m50 swap, keep it basic, and BAR it. best way to go. can even keep the getrag240 in place.

Still ~2500 bucks. I was about to look into it but apparently the 24v wiki is down. Anyone know what I'd need to get/do other than engine, e34 pan, e36 mount arms, wiring, ecu, exhaust, driveshaft?

[golde30]

m50 swap, keep it basic, and BAR it. best way to go. can even keep the getrag240 in place.

[kronus]

toddness has a good M42

[Vivek]

Well shit. The eBay seller who had an m42 listed with 5 available said he has none for an e30. So I suppose he might have had an m44 listed as an m42? It didn't have the intake mani on so I couldn't tell much from the pic.

Does anyone know where to get an engine that is tested and has a warranty? Preferably as close to the Bay Area as possible.

I could also try to fix my old engine...not quite sure what's wrong with that. But it's been sitting outside for months and I'm pretty sure has gotten water in at least one of the cylinders due to not having an intake manifold installed.

[Vivek]

Well shit. The eBay seller who had an m42 listed with 5 available said he has none for an e30. So I suppose he might have had an m44 listed as an m42? It didn't have the intake mani on so I couldn't tell much from the pic.

Does anyone know where to get an engine that is tested and has a warranty? Preferably as close to the Bay Area as possible.

I could also try to fix my old engine...not quite sure what's wrong with that. But it's been sitting outside for months and I'm pretty sure has gotten water in at least one of the cylinders due to not having an intake manifold installed.

[wazzu70]

Yeah, its major work to get to the oil pump.

Have you checked to see if there is oil in the valve cover area?


A new/verified engine may be the best route.