Author Topic: E30 M42 low oil pressure, runs VERY loud/rough  (Read 4289 times)

Vivek

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E30 M42 low oil pressure, runs VERY loud/rough
« on: March 21, 2014, 09:27:23 AM »
So I overheated my old engine and replaced it with a newer m42. I did an m20 flywheel/clutch swap, most gaskets (upper/lower oil pan, upper/lower intake, oil filter housing, valve cover) except the head and profile. I checked all the upper pan bolts and they're good and tight. I replaced the timing chain tensioner because the timing chain had just started to make noise (got the engine from a good friend). Cam gears look brand new. Didn't touch the guides.

So here's my problem. I start it up and it idles fine but I've run it for less than a minute total because it's loud as hell and I don't want to risk damaging anything in this engine that I've put so much work into. I hope the link below works, it's loud as fuck. My oil pressure light comes on and stays on. My guess is that the chain tensioner isn't getting oil so it isn't adequately tensioning the chain. A couple of the plug wires (3&4) weren't fully connected but that made no difference once I fixed it. Any help would be greatly appreciated
Vivek

http://youtu.be/CuXx-4TR_0g

deansweet

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Re: E30 M42 low oil pressure, runs VERY loud/rough
« Reply #1 on: March 21, 2014, 12:14:12 PM »
Plug wires connected in right order? Cylinder #1 is in front of engine(towards radiator).

deansweet

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Re: E30 M42 low oil pressure, runs VERY loud/rough
« Reply #2 on: March 21, 2014, 12:16:56 PM »
And pull and check the oil filter housing. Mine made that exact same noise when I replaced his oil filter gasket and I found out the o-ring going in to block had sheared when i put it in.  If you live anywhere near Southwest Ohio I'd be more than happy to come help out.

Vivek

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Re: E30 M42 low oil pressure, runs VERY loud/rough
« Reply #3 on: March 21, 2014, 03:21:23 PM »
I'm fairly certain I have my wires in the right order. The wires I have I believe are stock and are numbered. If I pull the oil filter housing, I should get a new gasket and o-ring, right? Is there anything else it may be? I assembled everything outside the car, so I'd say that decreases the likelihood I may have messed something up, but at the same time this is my first time replacing an engine. Thanks for the offer to help me out. I live in California (San Jose) so if anyone wants to come over for pizza/beer/money....

Does this sound like anything to do with the coils/wires/plugs? If it was something like that it'd be easy, but I kinda doubt it.

keflaman

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Re: E30 M42 low oil pressure, runs VERY loud/rough
« Reply #4 on: March 21, 2014, 07:56:56 PM »
Tell us what procedure you used to install the tensioner. I think it's possible it hasn't "extended" to place tension on the chain and that's what you're hearing. Search around in past threads about it. IIRC, if you don't install it extended you have to rev it up to pressurize the tensioner and it will make a racket like you're hearing.

On another note, I hope you've fully recovered!

SkidMark

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Re: E30 M42 low oil pressure, runs VERY loud/rough
« Reply #5 on: March 21, 2014, 10:47:48 PM »
I agree with keflaman,
It definitely sounds like the tensioner has not extended. When I recently did mine I put it in compressed and had to run the engine up past 3500 rpm to get the oil press up enough to open it. It was really scary as it was VERY noisy and sounded like somebody threw a handful of bolts in the head. It rattled and clacked for a minute then the noises went away and all is well. The plunger in the tensioner is held compressed by a small clip that releases under oil pressure. If I was you I would remove the tensioner and see if it is extended. If it is not you can put it in extended if I am not mistaken. Then it will at least have the spring pressure on the timing chain so it shouldn't be quite as loud until it gets oil pressure...If it is extended you will need to bleed it down to re install it or you WILL damage the timing chain, gears and guides!!! Hope this helps bro....
1970 BMW 2002, 1988 BMW 325ix, 1979 BMW 320i m42 powered race car, 1969 BMW r75 cafe bike, Greasy fingers, Empty bank acct, Pissed off wife, Unhappy dog, Filthy garage.

romkasponka

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Re: E30 M42 low oil pressure, runs VERY loud/rough
« Reply #6 on: March 22, 2014, 03:28:37 AM »
Normaly ratle like this should disapier after few minutes with tensioner extended and valve compensators filled with oil. As I remember to get tensioner extendet you should rev engine to 3500 rpm for 1 minute or something.
E30 318is M42
E36 318is M44

e30dennis

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Re: E30 M42 low oil pressure, runs VERY loud/rough
« Reply #7 on: April 12, 2014, 05:18:38 PM »
Hey i have the same issue but i found the problem

e30dennis

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Re: E30 M42 low oil pressure, runs VERY loud/rough
« Reply #8 on: April 12, 2014, 05:19:57 PM »
check if its lose