Hi guys. Been a long time lurker on here. Now I could use some Ideas from the experts so here goes my first post...
Last month I gathered all parts for a full timing belt / wp / plugs and wires job on my 96 SR.
Keep in mind prior to this I have no oil leaks ( at last nothing noticeble )
I gave all the parts to my mechanic and he did the job.
Two days later truck is running but I notice its dripping oil at a fast rate around the front of the oil pan.
So my mechanic figured he had screwed up on the crank seal somewhere. So over a weekend he tore the truck down again and replaced the crank
seal with a new one. He mentioned that he did not see any traces of oil anywhere around the crank seal or the cam seals.
Once all back together we start the truck and second later the oil drip persisted.
So I put it up on the lift and I notice it was dripping off of the oil pressure sender right next to the oil filter.
With a little digging around I noticed one of the oil cooler hoses was leaking pretty around the collar. Since it is right above the oil pressure sender
I replaced it and the sender ( for good measure ).
This was yesterday.
New hose in. Ran the truck at idle for 10-15 minutes. Not a drip. Test drove it for another 15 minutes.
Looked under , and one single drip fell in the course of 60 seconds. Didn't think much of it.
Drove home from work and all seemed fine.
This morning I drove the truck to work and once I got here I could smell the oil burning smell.
So I leave the truck running and look underneath and I've got oil dripping at a fast rate again.
This time its dripping from the front of the oil pain right under the harmonic balancer....
At this point i'm confused and very frusterated by all this.
Is this the crank seal that all of a sudden goes bad a week later ? Is this running off somewhere else and dripping onto the harmonic balancer making it look
like it the crank seal ? Any suggestions are appreciated.
This really sucks not only because of the obvious frusteration but also because I've got a buyer lined up for tomorrow for my 97 LS ( my other truck )
and I'd be stuck trying to figure out this oil leak mess with only one vehicle for my family of 4. <img src="/forums/images/graemlins/confused.gif" alt="" />

Oil pressure regulator? Not familiar with that part. Sending unit or relief valve maybe?

Anyways, on the leak. Not saying this is the problem but others have experienced this on the 3.5 DOHC, so its worth a look. I had a leak like that one time right after a timing belt change. Turned out to be oil dripping out from behind one of the bolts that mount the hydraulic tensioner to the engine. These bolts pass through the oil pump and into the block. My theory is the gasket back there between the oil pump and block goes bad. Anyways I fixed it by putting a small amount of RTV on the back of the tensioner bolt hole and a copper sealing washer behind the bolt head. Also put teflon tape on the bolt threads (not sure that step did anything as threads are in the block) May or may not be your problem but worth a look.

Meant to write sender not regulater. Thanks for catching that.
Thanks for the tip I will definitely look into it!

Looking deeper into that, the threads of the tensioner mounting bolts enter an oil gallery in the block, so sealant on the threads is a good idea there.

I just finished my timing belt job on my 94 SR. The two bolts for the tensioner are different than any of the other bolts, The body after the threaded portion is smaller than the major diameter of the threads. Maybe if your mechanic mixed up the bolts, it might have some affect on the oil passages.

Thanks guys!. Ill pay some extra attention to these bolts.
I went ahead and ordered an OEM crank seal from Mitsubishi.
The seal we swapped on there the last time is a Taiwan seal from my local Autozone that I bought in the interest of time.
Never had so much trouble with sealing an engine that wasn't leaking to begin with.... <img src="/forums/images/graemlins/angry.gif" alt="" />

I had a similar thing happen to me when i changed my crank seal. Turns out the problem was that a slight sharp edge had built up around the seal bore so that when I pressed in the new seal the sharp edge was tearing and shaving off a small amount of the rubber material of the seal causing the seal to....well not seal. It was a pretty fast rate leak as well. I bought a de-burring tool (handtool)and it worked like a charm. Did the seal that the mechanic put in have any cuts and damage to it's outside sealing surface? Have you run it with the timing cover off to get a look at what's leaking exactly? I posted about this on here where you can see some pictures of my seal and the de-burring tool.

If it's not a cam seal then it's either the crank seal or the oil pump to main seal mentioned above. Good luck!

As one who has my hands in lots of Mitsu motors .. The crank seal bore should be de-bured ..And crank end .. And be careful on the sael install ..Or the will leak...

Ditto on deburring the outer corner of the seal bore, just knock off the sharp edge. Also, pack the rear (inner side) recess on the seal, where the little coil spring lives, with grease. I like to use silicone grease, and grease the seal rubber lip and the seal bore, too, for easier driving. I've had two types of failures with driving front seals. One, you cut the outer rim rubber with the sharp corner on the pump bore, or two, you rattle the little spring out when you are driving the seal. The grease holds the spring in while driving, and eases the seal's passage into the bore. I've also used a smear of rtv on the outer rim with success, both lubing the intstall (drive it while rtv us still wet) and providing extra sealing of the rim in case you have a scratch in the bore. oem seals are very good.

One way to find the leak source. Tear it down to bare the front and use an ear syringe, the little rubber bulb and spout, and some baby powder and dust the front of the engine and sides around the oil filter appliance. Gently blow the loose powder away and the rest, stuck on the oil path, will show you where it ran from (and was blown/flung to, but you can see the solid track most of the time.

The really best trick is UV dye in the oil and a black light, but it's not real cheap.

Green food coloring in the oil can be the white trash UV tool ... <img src="/forums/images/graemlins/notooth.gif" alt="" />...

It seems that most seals have the OD just a few thou to big...They work but just a pain to get installed 'right'... Now add a beat up crank end from a loose crank pully...I cut two seals doing my V6 ...Cut one and chickened out on one more 'thinking' I cut it...Got the third one and no leak..