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

[Vivek]

I'm running castrol regular oil 20w50. I pretty much smeared it around everywhere over the gaskets on both sides. I'm pretty sure it was all around every bolt hole and lines in between the bolts. It's now a bitch to get the lower pan off. Is there any way to do it other than hammering a chisel in there? And since I took the lower pan bolts out, I'm pretty sure my issue is that they weren't torqued enough. I'll need to find the spec for these bolts and a wrench that'll do it.

[bmwman91]

I don't know of any really easy way to get the pan off with the adhesive. Sounds like some brute force is in order.

[roguetoaster]

If you need to pry on the pan there are tabs on the front you can lever against (as you pry you can stick a utility knife blade in the area that opens). That combined with a few taps from a rubber mallet should take it off.

Just don't use a chisel or screwdriver between the sealing surfaces except as a very last resort.

[Vivek]

Okay FINALLY got both pans off. The lower one took forever because I couldn't get it to separate. On the upper I stripped one of the torx bolts on the bell housing and that took a couple days to remove. Fucking pain in the ass. Anyways, here's some pics:
Oil pickup:


Gasket around the oil pickup:

Oil pickup port. Note that it looks/feels completely dry. Would a stuck relief valve cause that?

And here's the valve I pulled out


Parts I have ready to go on are new OEM upper and lower gaskets, new tube of hondabond, and all 4 parts of the valve (upper, lower, spring, circlip). The valve is the updated nylon design.

[Vivek]

Anyone? I'd like to assemble this ASAP but I don't wanna put back together and find out it's like the oil pump or something else.

[bmwman91]

It is good that you got the updated parts in. Was the old one stuck or jammed at all?

Considering how long the thing sat for, I wouldn't be surprised if the inlet felt pretty dry.

If this wasn't it then I am totally stumped. The only other thing I could think would be that there are no pump geats in the timing case, but if it was running fine before and the case was not off at any point then that is not a possibility.

[Vivek]

Well I saw no real signs of damage on the valve, but I really have no clue what to look for. Hopefully it's just the valve and it'll be all good upon reassambly.

[Vivek]

I should lube the valve before putting it in, right? Stupid questions but I don't wanna screw up something simple on this job by not asking.

[bmwman91]

Yeah, it is probably a good idea to dip it in some motor oil.

[Vivek]

Well I would drive off a fucking bridge but I don't have a car to take.

It still won't FUCKING work. I got the new part. Oil it up. Put it back in. New hondabond. New gaskets. Spent a fucking month doing it. I started it up just now and it has the SAME exact issue. Oil pressure light on, loud as fuck chain rattle. Fuck this I'm taking it to an E30 shop and bending over for whatever they're gonna charge me.

Could the new chain tensioner possibly be a dud? I would be so fucking mad if I spent so long replacing a part and it's something else that would take my 5 minutes to replace.

I've run it for about 30 seconds total after doing this. Started it up, it revved to 4k and started dropping, stopped because I didn't wanna fuck it up. Realized I didn't check if the oil pressure light was on, maybe it's just the tensioner getting pressure. Started it up again, revs to 5k, light is on, turned it off. Looked under the hood and realized the throttle cable was not seated, fixed that…started it up again just to check. Idled perfectly, but the rattle is still deafening.

[roguetoaster]

I am very sorry to hear that the same issue is back after all of that work.

1. Take the tensioner out, separate it, inspect it. If all is well visually make sure it has oil in it from the get go, reinstall and try again.

2. Assuming the rattle is still there start taking off things you can to check to see where oil is going/not going (VC, oil filter cap, oil filler cap). Maybe even take the cap off and put clear plastic over the opening to check oil sling. If oil is circulating everywhere then IDK what else it could be besides magical low pressure.

I can't remember if you had the front cover off, if not maybe you have something loose or poorly seated in the timing system. Save the bridge driving off thing for later when you find the simple problem that was right in front of you all along.

[uturn]

If I had seen you post earlier I would have said go ahead and change out the oil pump.... another $50 part + $15 gasket for piece of mind. The two profile gaskets - VR ones don't fit properly, use the BMW ones to seal properly. The tensioner issue, I think you might have stretched your timing chain. To properly install it you have to break it down, compress it two or three clicks in so it stays in(the last click will disengage the piston and it will come back out). Install it then push on the rail to engage it. It'll pop out and adjust itself as needed. There's also the possibility of valve tick because of bad lifters but that could also be because of no oil getting to them. I feel for you man...

[bmwman91]

Shit dude, really sorry to hear this. I cannot imagine what it is at this point if the oil pressure light is on (and you measured a big zero), other than a completely destroyed or missing set of oil pump gears. You said that this engine was running strong when you bought it, and you didn't swap or do anything with the timing case right? The only way I can think that the oil pump is not operating is if the PO of the engine blew out the gears and sold you a dud.

I know how you are feeling as I was there about a year ago. I had waited a year for a custom M42 to be built and had a valve spring crap out 70 miles in. Pulled the engine and shipped it to the builder to get fixed. Put it back, things were going well, and then another one broke at 1000 miles. I was seriously going to get the head fixed and sell the bastard. Buy a used Civic and get from A to B with no more bullshit. Thankfully, I had some guys on M42Club keep up the encouragement (Warsteiner, wazzu, DesktopDave) and it turned out fine. It took hours of bloody knuckles, sweating and anger to get through it, but it all worked out. You'll be fine too, and in a few months it won't be a big deal for you.

[wazzu70]

Do as stated and see if oil is flowing to the valve cover. That should answer quickly if oil is circulating or not.

If its not flowing, you either have a bad oil pump (unlikely) or a big leak in the oil system. One area this can form is if a piston oil squirter off the main galley fell out.

Check the easy stuff first though. Probably something easy :)

[bmwman91]

Do as stated and see if oil is flowing to the valve cover. That should answer quickly if oil is circulating or not.

If its not flowing, you either have a bad oil pump (unlikely) or a big leak in the oil system. One area this can form is if a piston oil squirter off the main galley fell out.

Check the easy stuff first though. Probably something easy :)

Before he changed the relief valve, he put a pressure tester on where the sender is and got a 0PSI reading, and no oil came out of there. If it was a big leak somewhere downstream, I think that he'd at least register something there, no? This is like the M42 caper of the decade right here. Not sure what's at fault, but the culprit sure is a bastard!