oil pump "shaft" got hungry and nibbled away at my block, so ihave a few Q's

[dsm_dan]

ok here goes.
1st of all i checked all over and checked vfaq and got a "can not find server"

mods and such
1990 6 bolt block
2g pistons
new timing belt water pump and tensioner
ported head
all new bearings
Thats about all for the longblock

(balance shaft belt was left off since when i took the timing belt off the balance shaft belt had already been torn up in 3 pieces... again, this is not "removed" just no balance shaft belt.

not sure but the oil pump timing mark MAY have been off a tooth

ok anywas:
The oil pump has a shaft that goes through the block on the back side. Just like the balance shaft only the balance shaft is in the front. in the middle of this shaft there is a circular cut out in thw web casting of the block and a rod bearing type bearing secures the shaft in the webbing" of the block... a "sleeve" if you will.

Now, after i put the belt and all that on... the car started making a metalic buzzing noise... sort of like if you hold a screwdriver on fan blades or if you ride over a can with a bycle and it gets wedged between the forks of the bike. ( best way i can describe it) I figured the belt or a pully might be rubbing on the timing cover... so i take the timing cover off and run the car... still did it but by this time it got considerably louder AND the oil pressure was piss poor... not so little that the rod bearings and such were being neglected but considerably low... would not go past the 1st "notch". Anyway, i pin pointed the noise... coming from the pan.... very loud. So i drop the pan and there is the sleeve for the oil pump shaft all chewed up by the crank and other rotating assembly peices. so i look up nad give the oil pump shaft a good look and i notice that the shaft is flapping all round with a GREAT deal of play. (definately the noise ). then i see wher ethe sleev goes and i notice that from spinning fast and out of whack, the shaft is worn and chewed up... as is the block. In other words, there is no way even with a new "sleeve" that the shaft will not have tremendos play in it. The oil pump sprocket is tight and fine... its the whole shaft in the block that is wobbling. Later on i notice the balance shaft is basically the same deal. and there are balance shaft eliminator kits. now, i just didnt put teh belt on the balancer shaft... just left it be without a belt.

could this have cause the wearing of teh sleeve and surrounding block area? or maybe the oil pump sprocket was off a tooth or 2?

also, can you eliminate the oil pump shaft (aka second balance shaft i heard it's called also) this way i dont have to worry about the chewed up area in teh block where the shaft went?

ill try to get pictures, what do you guys suggest i do?
How should i tackle this? Has anypne here ever expeirieced this "oil shaft wearing out" deal before??? im lost and dont know where to start and who to ask. And its kinda vague and not easy to see what im talkin about but its the best i can do, thanks guys!
it would be great if i didnt need a new block and i could just take the whole shaft out and not worry about the damned thing, this whole rebuild has killed me !!

 

[moidsm1]

i have that same exact problem except my oil pressure is still good. That rear oil pump shaft is also a balance shaft. I just ordered parts from mitsubishi to do the balance shaft removal mod.

 

[dsm_dan]

yeah but do both shafts come out or just the one front one? if they both come out that would be good because its a fresh motor, rebuilt it myself. I bought a shortblock last night and it may turn out i dont even need it... Ill try and take some pics tonight of everything. Maybe It can hlp some people, me inparticular! . Any input is greatly appreciated

 

[dsm_dan]

Ok well vfaq worked this time around and yes both shafts come out and it should totally eliminate the problem... but im throwin an oil pump in it anyway. The job doesnt look too bad, even with the motor in the car... id say its a "wake up early (9:00- 10:00 ) on sunday morning , bust ur ass till lunch and have it running 100% by 1:00 all bugs and leaks checked out" kind of job. at least i hope so

we'll see how it goes

Man, one of the best things about owning a dsm is definately www.vfaq.com

 

[steve]

If your lower balance shaft dropped the rear bearing and flopped around like you described I would guess it also eat up the inside of the oil pump/front case.
It's expensive to replace but you'll also get new front seals (except for the cam seals, replace them too) when you buy a new front case. Get the later pump gears and a Mirage stub shaft. The old style gears were straight cut and noisy. Mitsu had a TSB out for replacing them with the later gears.

Steve

 

[moidsm1]

When i took off my front case to inspect it, the rear balance bearing was in the oil pan. the balance shaft was indeed flopping around in there and making a knocking sound as if the motor was bad. I guess today will be junk yard shopping day. steve your probably right about the oil pump being worn out. hope this info helps out dsm dan

 

[20over4g63]

Originally posted by moidsm1
When i took off my front case to inspect it, the rear balance bearing was in the oil pan. the balance shaft was indeed flopping around in there and making a knocking sound as if the motor was bad. I guess today will be junk yard shopping day. steve your probably right about the oil pump being worn out. hope this info helps out dsm dan

I had the exact same problem on my last motor. It sounded exactly like a buzzing sound. It made the knock sensor retard the timing so far back it would barely run...I did'nt have it so lucky, the bearing was in the bottom of the pan, some of the metal got in the oil and was circulated in the motor. chewed up the crank, and the cam journels. I threw those stupid things in the trash, and payed 20 bucks for the balance shaft elimination kit. Had to buy a core motor and rebuild it. Good idea to replace the oil pump. I drove crap out of the car when it made that noise. It sounded awful.