Figured I'd post thus up just in case anyone else has the same issues. Past or future.

About two weeks ago I started to develop an oil leak. I narrowed it down to the oil pump. I figured that the oil pump seal had just went bad and needed replacing.

I got the new seal in over the weekend and she still leaked. I took her back apart and this is what I saw. Anyone else ever had this happen? Looks like I'll be putting a new front case on now.

 

This has happened on two different occasions to my buddies car, and has taken out his motor both times... I can only speculate that the timing belt is tensioned incorrectly or perhaps the oil pump sprocket had burrs and ate itself up...

 

Thanks for your response. At least I'm not the only one. Guess I can figure out the reason once I pull the case off.

 

Please post up your findings as I would like to see what can be done to curtail this in the future...

 

Will do.

 

Damn that sucks but good find. That's the crappies gasket and part to replace also while the motor is in the car. I just removed my motor to do it since I need to do other things anyways.

 

I'm about to be check mine since my motor is still on the stand lol this gets me worried

 

It shouldn't be too hard for me. I've done the timing belt with help from friends about 4-5 times now.

Just gotta take the pass mount out and drop the dp and lower engine mount brace. Got all sorts of room then lol

 

When I initially took it apart to look at it the seal was sitting halfway out of where the sprocket meets the case. I figured that it was just worn. Then I realized that the shaft itself had play.

What I imagine happened is that when there is tension on the timing belt it is letting oil pass through around the shaft and pushing the seal out.

I've got a new case on the way and will post pics of the carnage on the broken pump/shaft.

My car is sitting at 81k miles and has been sitting at over 500 hp/440 tq for the past 7 months or so.

 

Finally got around to pulling the case off. Biggest pain in the **** was the crankshaft sprocket bolt. the service manual says 120 lb ft but there is no way lol. I sat on it for about 30 secs with a 200 ft lb impact gun and it finally loosened. Discoveries are below.

It looks likea pice of the oil pump case broke off and that is what caused the oil pump gear to become loose and leak oil. Thankfully i caught it now because this probably could have become alot worse.

Reason it broke? I have no idea. the aluminum used in that area is pretty thin. You'd think they (mitsubishi) would use something stronger in this area.



Notice all of the scoring on the shaft.


The piece where it broke off





don't mind the shavings around the area. the damned phillips head bolt in the pump cover stripped and i just drilled it out as i have a new case already. I'm guessing people use an impact driver to get that phillips head off? I don't know why they would even use a phillips head there when there are 4 other 12mm bolts.

 

What kind of oil pan was used in the car? I just ask because oil pump failures are common in cars that launch hard or have a lot of lateral gs. The oil pump is supported from the oil pressure so in certain high g launches or turns you can starve the oil pump easily. This is one of the reasons behind dry sumps and the new bearing supported oil pump/front case setups.

 

Stock pan. Ive probably done less than 10 launches in this car. I guess all it would take is one good time. What front case are you speaking of?

 

you are not diagnosing correctly. your oil pump loosened first. the loose gear is what caused the alloy to brake. not the other way around. the phillips head screw is there because the cover wont fit on the engine if there is a bolt head there. hand held impact works well. but you can also hammer on a screwdriver to break threads loose first before stripping the head out. your main and rod bearings are gonna be in poor shape. and maybe the whole engine as well. a lot of shavings has gone through the engine. every bearing surface will be scored. the whole engine needs to come apart. every oil way needs to be cleaned and every surface polished. just replacing pump will only buy some time.

 

Hmm.. i don't think you understand what i wrote. I have a brand new front case/pump that is going on the car. there were no shavings or anything in the pan when i pulled it. the pics you see here are of the old front case and pump gear.

 

Frontline Fab has a machined front case to accept bearing that doesn't rely on the oil supply for support. I believe he is still in development stages. But yes what 94AWDcoupe is getting at is with an oil pump failure like the one you have, it is very likely you pushed metal shavings through your engine. The chunk you see that broke off is most likely cause by the pump wearing and developing enough play to make contact with the front case. You will see very fine metallic flakes floating in the oil. Ideally you could have collected an oil sample and sent it off for analysis to confirm if excessive bearing material is present in the oil. Very slim chance that there isn't already damage done.

If you pull some rod bearing caps or crank caps you can see if you have any damage from contamination by looking at them. The oil cooler is notorious for having shavings stuck in it and if reused on the new engine will damage it again. I would start there to see if it has any contaminants.