[John Wood]

I did all the seals on my Mitsu 3.0 (96 model but same thing) at about 150,000 miles. If you are going to tear the front down, take care of everything (unless you enjoy taking these apart ). I went as far as putting repair sleeves on the two camshafts and the crankshaft. I opted to do this after read John Blair's oil leak horror story which can be found here on Allpar. In addition to that, I replaced the rear camshaft plugs and the valve cover gaskets, as well as the oil pan gasket. When I had the tranny out, for replacement, I put a sleeve of the rear crank along with a new seal. I'm happy to say it is 100% tight at 214,000 miles and I have no drips on my concrete driveway. By everything, I mean timing belt and water pump (flush your cooling system thoroughly first).

 

[Brewster_440]

yea, did the water pump (and new timing belt) at about 120,000. engine has 148,000 on it now. not pulling the trans. may do the oil pan, but for now i want the "bleeding" to stop! LOL

 

[John Wood]

yea, did the water pump (and new timing belt) at about 120,000. engine has 148,000 on it now. not pulling the trans. may do the oil pan, but for now i want the "bleeding" to stop! LOL

The timing belt will need to come off to do any of the front seals. If you find that the timing belt has been contaminated with oil due to leakage, it would be wise to replace the belt prematurely anyhow. The belts can be found on E-Bay, Amazon, or Rock Auto fairly cheaply.

Everything you need to know is at this link (fully illustrated):

http://www.emprepcourse.com/mitsubishi/index.html

I wouldn't worry about the rear main, but if some time in the future you need to R&R the tranny, get a repair sleeve and seal for the rear crank.

 

[chuzz]

I had a 93 Diamante wagon with the 3.0. That sucker started leaking oil pretty bad and it turned out to be my oil sending unit. I got a new one and installed it and that cured mine.

 

[ImperialCrown]

It is wise to degrease the engine first and then assess the oil leak(s). The lower ends on these motors usually held together pretty well. It was the cam seals and valve cover gaskets that started leaking oil in many cases, especially the rear bank that ran warmer. This can drip off the bell-housing and make it look like a rear main seal.
If the exhaust doesn't smoke, then your valve seals are probably OK.
Oil will leak down (gravity) and back (road draft), but with the wind turbulence at the rear of the engine, it can go everywhere.
A leak at the oil filter adapter/oil pressure sender at the front of the motor can blow back and look like an oil pan gasket leak.