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

[Vivek]

Well new little issue that I may as well put in this thread instead of making another. I drove it. Drives fine (only took it to like 25mph). But it's getting warm and I don't think my coolant is flowing. My electric fan isn't kicking on and I have an e36 temp sender meant for an electrical fan. Also to bleed the coolant I always just poured it in the reservoir and revved it so it bubbled and the level went down, then filled more and repeat til there's no more bubbles. Now it doesn't seem like its flowing through the tubes at all and idk if any is even in the engine.

I filled it up with all the hoses connected and just poured it in the tank with the engine off. It seemed like it flowed into the engine and there's no reason for the water pump to be bad (worked when pulled and I didn't touch it). Do I have to prime this damn thing too??

Here's some pics:


Skid plate clearance (I can just barely get into my driveway at this height so it'll likely stay about this height unless my is lip is a huge hindrance which I doubt):

[kwill22]

Sweet man good to hear! Glad it's up and running

[bmwm42]

Highly doubt the pump is bad if your no longer getting lifter tick....I just mentioned that the oil pump needed to be primed not that it was bad

[Vivek]

I've said it all along I'm blaming the oil pump

Ahhh nice feeling knowing I was right all along...glad you got it fixed btw!

It wasn't quite the pump, more that it wasn't priming. I'll run the oil while I'm bleeding the coolant and then change it. I'll probably stick on the magnetic plug first and see how fucked it is.

Anyways, yeah does anyone know if this means the pumps on its way out or can this happen to a brand new one?

[bmwman91]

Ahhh nice feeling knowing I was right all along...glad you got it fixed btw!

Good call dude. So, is it possible that the trouble is indicative of worn-out pump gears, or can this happen just as easily with new ones?

[bmwm42]

Ahhh nice feeling knowing I was right all along...glad you got it fixed btw!

[bmwman91]

If you have run it for a few minutes already then I'd say change the oil. The gear oil probably isn't hurting anything in there but it's probably good to flush it out.

[Vivek]

Not having the cap on after oil started to pump was your problem. If I were you I would change the oil right now and inspect it. Also look though the oil cap hole with a flashlight at the cams.

I did that yesterday before it got oil pressure and the lobe I can see is actually in excellent condition. I'm gonna change the oil immediately since it has like 6 quarts and some gear oil. Should I also change the filter because it got gear oil on it? And I agree, when I primed it the other day and it started to overflow, it was probably primed then. Then when I put the cap on it could actually build pressure.

Hey, great news! I have never ever heard of such a ridiculous ordeal involving priming an oil pump, although it sounds like a few others have. Glad it is running. I recommend pulling the valve cover and giving things a look. Also, get yourself a magnetic oil drain plug ASAP, they are very handy for collecting iron tidbits and keeping them out of circulation. Turner Motorsport sells them, and probably other places.

And at least you know that your bypass valve is now fresh and of the current design. I still say think about replacing the oil pump at some point, but maybe relax and drive it for a while before embarking on another adventure. At that point, I'd say to swap in a later M42 case or M44 case without the idler sprocket. Anyway, I know that more wrenching project are the LAST thing on your mind now so go enjoy the car!

I actually have a magnetic drain plug ready to go on. Any tips on what I should do with the oil that's in it? It's about a quart of gear oil and 5 quarts of castrol 20w50. Should I run it for a couple minutes to maybe get it to flow throughout the engine and remove any metal deposits, or replace it immediately?


Also thanks for all the encouragement guys. I just have a few things to button up on my car and it should be driving after this weekend.

[bmwman91]

Hey, great news! I have never ever heard of such a ridiculous ordeal involving priming an oil pump, although it sounds like a few others have. Glad it is running. I recommend pulling the valve cover and giving things a look. Also, get yourself a magnetic oil drain plug ASAP, they are very handy for collecting iron tidbits and keeping them out of circulation. Turner Motorsport sells them, and probably other places.

And at least you know that your bypass valve is now fresh and of the current design. I still say think about replacing the oil pump at some point, but maybe relax and drive it for a while before embarking on another adventure. At that point, I'd say to swap in a later M42 case or M44 case without the idler sprocket. Anyway, I know that more wrenching project are the LAST thing on your mind now so go enjoy the car!

[e304me]

Not having the cap on after oil started to pump was your problem. If I were you I would change the oil right now and inspect it. Also look though the oil cap hole with a flashlight at the cams.

[wazzu70]

Glad to hear you got it fixed!

[JinormusJ]

The following animation should explain how to put oil down the pump outlet and what to look for.

I have never lol'd so hard...


In my life..

[roguetoaster]

Well holy balls I think I actually fixed it. This thing was a bitch to prime. I eventually got it to work when I primed with gear oil, cranked, put on my oil filter cap, started it, and within 5 seconds the oil light went off and the timing chain quieted down. I suppose it's finally working.

Way to stick with it, congratulations!

[brads2002]

Awesome, i actually had this happen on a friends M42 a few years back. We gave up and swapped the motor. Glad you didn't. Great news!

[Vivek]

Well holy balls I think I actually fixed it. This thing was a bitch to prime. I eventually got it to work when I primed with gear oil, cranked, put on my oil filter cap, started it, and within 5 seconds the oil light went off and the timing chain quieted down. I suppose it's finally working.