Oil Pump replacement

[MDryVur]

whats up guys, so im picking up a 91 318i this weekend and the gentlemen says the oil pump is out...

now the question is have any of you guys changed the pump... im very savy with changing parts and such ive built my 325i engine years ago, but ive never owned a 4 cyl before..

can i get your help on this please.

im trying to search for the pump but all i get is the gear which is around 60 bucks, is that all i need?!

Thank you in advance

Matt

[///M42 sport]

I have 2 extra m42 engines if you need parts. not sure if I can advise you on anything since i'm a amatuer mech. I do know that replacing the oil pump requires replacing the profile gasket, waterpump. May need to replace the headgasket to do it properly. Its pretty labor intensive and easiest with the engine on a stand. Not sure why just the oil pump would have failed. Sounds weird to me and afaik is not a common problem with that engine. My m42 had about 300k miles on it and didnt have oil pump issues.

[Gerta]

Ok, as someone who has done this three times, this is a big job. The oil pump is internal to the M42 engine. It requires the front lower chain case to come off, so typically the head also comes off, making it a lot easier to do out of the car. Did I say it is also easier to do out of the car?

Realoem is your friend here. Shoot me a PM with your number if you want to talk live and I can even send you a pic of the parts ... and yes the pump itself is a two part gear that has a bolted on cover ... nothing fancy.

[Gerta]

Oh yeah, and congrats on picking up the 318i! Post up some pics or start a build thread.

[MDryVur]

Thank you so much guys... Worst comes to worst I'm going to pull the engine out and rebuild it or just buy a a used one ... I will message you guys shortly... I'm on my iPhone... Again thank you so much guys

[oldmann]

Oil pump is out? Need to make sure this is whats up. Hook a guage up in the oil pressure sending unit port.
May be the internal pan bolts have fell out at the pickup, or the gasket has squished out between the upper pan and block.
Pull lower pan to ck this out. Can lose oil pressure if either has happened.

[Gerta]

Oldmann - If that happened I bet he will need new bearings ... and most likely a visit to the machine shop.

[Balleristic31]

Make sure that the plugs for the oil pressure switch and temp sensor are not switched. Bought an m42 car that had the oil light permanently on because some dumb mechanic did this.

[MDryVur]

Lmaoo... What an asshole bro...

From what I know this guy "says" he was driving it heard something and its the oil pump

I'm already looking for an engine and I might have found a contender lol

[oldmann]

I just swapped a low mile m42 into my daily 2 weeks ago.

Found 3 internal oil pan bolts rolling around in the pan, none were from the critical areas for the pickup.

I resealed entire engine except the head, Internal bolts got loctite, CK out whatever you get.

[TobyB]

It's probably the timing chain.

Since the oil pump is driven off the crank, by the time it has real problems,
the whole engine is poo.

The filter housing with all its bypasses and releases, however, can give real trouble.
And leak like hell.

t

[Gerta]

Oldmann - I had one missing bolt and three that were so loose I could pull them out by hand without any effort at all. It certainly wasn't the oil pump there. I would seriously consider checking any motor that the OP gets at a machine shop. I mean, you have the engine out, why not make sure it is healthy before you put it back in?

When I did mine I replaced all the potential wear items and had the block and head freshened up. The engine is ready for another 300k miles.

OP: Seriously check out M42club.com ... lots of good information specifically about the M42 engine.

[irish44j]

seriously, before you go crazy just do as previously suggested and actually check to see if you're getting oil pressure, and it's not just a dummy light or some other problem. Could be the oil pressure relief valve getting stuck (a known problem if the car has the original metal one).

Will the engine actually run? Squirt some marvel mystery oil or something into the cylinders and then run it briefly. Even if you're getting no oil pressure, the engine will be ok for a little while of running. Hell, one of our race guys ran almost 3 hours at race speeds with NO oil in the engine (had a cracked pan, didn't know, ignored the light), and once refilled, that engine is still running fine years later ;)

[Gerta]

seriously, before you go crazy just do as previously suggested and actually check to see if you're getting oil pressure, and it's not just a dummy light or some other problem. Could be the oil pressure relief valve getting stuck (a known problem if the car has the original metal one).

Will the engine actually run? Squirt some marvel mystery oil or something into the cylinders and then run it briefly. Even if you're getting no oil pressure, the engine will be ok for a little while of running. Hell, one of our race guys ran almost 3 hours at race speeds with NO oil in the engine (had a cracked pan, didn't know, ignored the light), and once refilled, that engine is still running fine years later ;)

Irish - I always have heard that our cars are sensitive to the no oil issue. I know even the low oil pressure I had on start up ate up my bearings. Did you guys pull apart the engine after the race and how were the internals?

[MDryVur]

alright guys... so update... i went and checked out the car... pictures were sooo fucking deceiving.. the car had stab wounds... no joke .. fucking stab wounds.. the ower took out the front chain cover which looked demolished.. dings and dents everywhere.. so i decided to keep the cash in my pocket instead..

again... thank you to everyone that helped

Matt