oil pressure issues, help!

[2mAn]

Swap fires up right away, but is only showing 10psi at idle (cold start) according to the gauge. I also have a massive oil leak coming from the back of the engine. Motor was pulled and a new rear main seal was installed. Everything else on the back of the motor was verified to be good working order, but after reassembly, same result.

I am suspicous of the oil pump, because it didnt initially fit perfect and I had to enlarge the third bolt hole (the one not associated with the dowels). I was able to install it, but have always felt it was kinda sketch. The mechanic working on it isnt really convinced its the pump. I'm not either, but I cant think of anything else it could be. The pump is a used one from a E34 M50 car, motor is a Z3 M52.

Mechanic is wondering if the oil galleries are obstructed, but this is a rebuilt motor and the block was cleaned several times before it got back to me.We're worried that we need to pull the motor again and replace the oil pump and still get the same result...

thoughts?

[justin_l_]

Low oil pressure at idle is normal, when my car was warm it would barely register at idle. Possible the rear main is leaking, seen many failed attempts on rear mains with these.

Fix the oil leak first then worry about the pressure.

[2mAn]

This is at a COLD idle, it should be around 60psi. HOT idle is around 10psi, so that would be normal. They already changed the rear main and that didnt change anything. I have been reading that the pressure relief valve could be stuck open

[justin_l_]

Missed that... Pressure relief is a good possibility. Why didn't you stick with the original pump?

[2mAn]

I would've! Motor was bare, no manifolds, no accesories, etc. I tried to buy another M50 that was complete but needed a rebuild, but it got sold. I was left to buy parts here and there (ie nickel and dime).

Overall, Im still satisfied with how Ive done the build, this is just the last frustrating part for me

[e30rapidic]

did you check to make sure the oil squirters were in place??

I had the exact same issue.....

http://www.youtube.com/watch?v=VJ-ZVl6I_Ao

[328ijunkie]

Change the pickup gasket? I have never ever had to 'enlarge' any holes on the oil pump, that sounds sketch as hell....

[2mAn]

Found the problem. Mechanic overlooked a hole that apparantly only the aluminum block has. whoops! we didnt catch it at first because he thought it was a threaded hole for the trans and when we looked at his spare iron block, it didnt have the hole.

60psi of oil pressure now on cold start :)

as far as the oil pump itself goes, I think it had to do with the fact that I used a E34 M50 pump. not sure. I posted a picture of it on the FB page and many people (including the mechanic) said that enlarging the hole would be fine. It was always in the back of my mind...

[butters]

did you check to make sure the oil squirters were in place??

I had the exact same issue.....

http://www.youtube.com/watch?v=VJ-ZVl6I_Ao

Did you have to tear the engine back down?

[e30rapidic]

Did you have to tear the engine back down?

yah. live and learn!

[2mAn]

Did you have to tear the engine back down?

Not sure if that is directed to me, but my clutch was ruined from the oil so the trans came out, new disc installed and leak fixed.

Flying back up to Seattle to get it this weekend. Not leaving until its done. Dont tell my work that

[butters]

yah. live and learn!

Yikes. I suppose the engine has the come out to pull the crank for access? Sometimes I suspect a couple of my squirters may be stuck open. I just put in an oil pressure gauge so I'll find out for sure soon. I'm not sure I'm up for pulling the motor out.. unless an S54 is going in.