Author Topic: Engine swap bad problem - Low high RPM oil press (Read 4160 times)

Artem · « **on:** July 03, 2008, 01:32:36 AM »

Hey guys, I have a pretty serious problem in my car. It is currently at the mechanic's and he has been working on it for quite some time.

Here is the deal - after the swap, the new (95 M42) engine was making this whining noise that sounded just like an overtensioned belt.

Mechanic looked at it and tested the oil pressure and said that at high RPMs it is a bit too low (I am not exactly sure what he said but I believe it was about 52PSI if i recall correctly at RPMs higher than 3k.) At low RPMs its fine.

He fears it might be something in the oil system, like a pickup tube, well he tested all the seals and such, and determined the tube and gaskets to be fine.

Does anyone have any ideas? Have anyone experienced something like that before?

-Thank you all in advance, Artem

EN318isPDX · « **Reply #1 on:** July 03, 2008, 01:25:06 PM »

Drugs are bad... mkay

peerless · « **Reply #2 on:** July 03, 2008, 01:28:51 PM »

All you need to know regarding oil pressure is 10psi for every 1000rpms.

52psi at high rpms on a warm engine is plenty. The stock spec for oil pressure is 18psi at warm idle. The oil light trips at 2.1psi, worthless.

Have you or a previous owner done any work to the timing components such as a new tensioner?

I just had a rebuilt M42 make the same whine. Yet on another M42 with a identical build it did not make the whine. All timing components where new and both short blocks where built to the same specs. The only difference between the 2 was the whiny one was a 93 E36 M42 and the non-whiny one was a 90 E30 M42. Are the E36 M42's just a bunch of whiny pussies? lol.
Does it sound like the following video:

peerless · « **Reply #3 on:** July 03, 2008, 01:33:40 PM »

Quote from: EN318isPDX;52533

I'd recommend posting this over on http://www.r3vlimited.com, they have a section for 24v swaps. alot more people over there run S52 and M50s. This forum are all of us 16 valvers.

HUH?

He stated he swapped in a 95' M42, where do you get 24 valves out of that?

Reading is not a crime.

Quote

Here is the deal - after the swap, the new (95 M42) engine was making this whining noise that sounded just like an overtensioned belt.

EN318isPDX · « **Reply #4 on:** July 03, 2008, 01:46:27 PM »

Ohhhhhh my mistake! i thought i saw 95 S52 or something..

Artem · « **Reply #5 on:** July 03, 2008, 02:52:26 PM »

Yes!! The video sounds exactly like my motor. What is up with that? Did you manage to fix it, peerless?

You guys are awesome! :-)

Artem · « **Reply #6 on:** July 03, 2008, 03:03:15 PM »

I think my mechanic said that my oil pressure DOESNT go ABOVE 52PSI

How long has your engine been running like that, peerless?

peerless · « **Reply #7 on:** July 03, 2008, 04:15:42 PM »

Quote from: Artem;52548

I think my mechanic said that my oil pressure DOESNT go ABOVE 52PSI

How long has your engine been running like that, peerless?

We swapped in another tensioner and it quieted down alot. Try pulling the tensioner, inspecting it. Then re-compress it to get all the oil out of it and reinstall. Do not compress it past the snap ring.

Regarding the oil pressure, it depends on the accuracy of his gauge and I doubt he took it past 5K rpms. 10psi for every 1000rpm.

Artem · « **Reply #8 on:** July 03, 2008, 06:09:53 PM »

Yea, I just talked to him, he said something about 32 psi or something. It might be a tensioner i suppose, I havent tried a different one yet. Will check it out after the 4th of july weekend.

Thanks a lot guys

!

bmw327 · « **Reply #9 on:** July 03, 2008, 07:26:52 PM »

Sounds like a tensioner to me. Mine mad precisely that noise when I bought it, I had the tensioner changed immediately, and the noise is gone.

Artem · « **Reply #10 on:** July 04, 2008, 01:20:36 AM »

Just for the record - you guys ARE talking about the chain tensioner, right?

-Artem

bmw327 · « **Reply #11 on:** July 04, 2008, 11:37:07 AM »

Yes, the chain tensioner is what I'm talking about...

Artem · « **Reply #12 on:** July 05, 2008, 02:43:07 AM »

Alright, sweet - will do that early next week. I'll get back at you with the result.

Thank you!!!

kenika65 · « **Reply #13 on:** July 05, 2008, 01:24:51 PM »

I always replace the timing chain tensioner when I get an M42 because it is great insurance and way to easy to replace.