BTW, can anyone explain to me why is there a PCV valve on the front of driver side valve cover (hose from there feeds back into intake manifold), but none on the passenger side hose which goes from the back of passenger side valve cover to the rubber air intake boot just before throttle body.?

 

Hunter ......PCV valve only on one side.....good question. Im not sure, but maybe they figgered that venting from one side was sufficient to meet EPA mandates.....I dunno.

Reason I mentioned possible High Oil Pressure is that I am having this issue with my 69 Chevy C10 with a 307 v8. Starts right up everytime, runs great down the highway, but after a 10 minute drive, I turn the engine off, and try to start.....the engine barely will turn over and not start. I have put new parts on everywhere, but still have the same issue. I then noticed that the oil pressure gauge is reading almost all the way on "High" on the gauge after starting up, and will slowly move down to 3/4 reading on the gauge.....which is still higher than she used to read. But when I let her idle after warming up, the pressure goes back to 1/4 on the gauge.....but going down the highway at 55, she is up between 3/4 to High. Not sure why that would cause the engine to not want to turn over when warmed-up, but maybe they are related. Im thinking maybe a clogged oil pick up screen or clogged oil gallery, or something clogged. So, maybe you have a similar issue.....high oil pressure.....and it causes your seal to pop out. Just a wild guess.

 

Well, I think I'm back in business. After pulling the engine a total of 4 times, I finally got the rear main resealed properly. The last seal was Nationan/Felpro. It has a metal body. Guess what... Montero engine did not like that. The seal did not dislodge, but the oil was leaking ever so slightly just between the seal carrier and the metal surface of the seal.
For the final attempt, I decided to do it by the book - I had removed oil pan and removed the seal carrier. Then install the seal into the carrier and after that bolt it onto the engine.
My very patient mechanic friend had helped me to seat the latest seal (seal with thick rubber body just like Mitsubishi and it is also made in Japan) very square into the seal carrier. We kept debating whether to drive it all the way down or just part way down into the groove. At the end we decided to use old metal seal as a "driver" below the press head we were using and pushed the seal solidly and smoothly all the way into the carrier. This way we were sure it was square in the carrier. In addition, after the seal was seated, he put six little dimples into the carrier surface on the outside of the seal. I also added another "safety" layer by putting a bead of Mitsubishi RTV (the stuff that is used on the oil pan) all along the edge of the seal and the seal carrier. Mounted carrier onto the engine, bolted back the oil pan and dropped the engine back in.
The Monty had been driven for several trips now and about 200 miles. So far so good. My wife says - it is too quiet, she is not used to it not making as much noise as it used too

 

Hunter.....great job, and finally done for the last and final time. So, we should avoid the metal type seal. Is the rubber one you used a Mitsu. part?

 

The last seal I used was not a MItsu OEM. I couldn't get OEM part delivered to me without delay, so I opted for an aftermarket. I ended up with the Fel-Pro BS 40660 seal kit. It looked just like the OEM seal - fully coated with rubberized compound on the outside of the seal and made from what looked like the same type of material (light brown compound). It was made in Japan and I swear if I had a new OEM seal out of the package next to it, I would not likely be able to tell them apart. I can't find the exact photo, but it looked sort of like this: https://encrypted-tbn0.gstatic.com/i...hXcN2&usqp=CAU
The one with the metal outside surface (the one that leaked along the outer edge) looked like this: https://external-content.duckduckgo....6pid%3DApi&f=1

Before the final attempt, I measured the outside diameter of the seal and the inner diameter of the seal carrier. The outer seal diameter was at least 0.1 mm larger than the opening in the seal carrier. The metal seal diameter was exactly the same as the seal carrier opening. Kind of curious to me. Makes me wonder if the rubber compound on the seal's outer seating surface is the "sacrificial" material. As we were pressing the seal in, you can see the small portions of the outer rubber deforming slightly and fully conforming to the seal carrier shape. One other thing I can't emphasize enough - MAKE SURE OUTER PART OF THE SEAL AND THE SEAL CARRIER IS SUPER SUPER CLEAN, DRY AND DEGREASED!!!!! While trying to do seal installation on the engine, I can see that I could never get the seal carrier completely dry of oil. I think that had contributed to the first seal slipping out.

 

Hunter.....Good info. I would have "thought" that those seals with the metal on the outside would be stronger and likely to last longer than the others. I guess the metal wrap helps the installer to lightly tap them in w/o damage, but not leak-proof like the others.

I would have thought using grease on the carrier hole would be the way to go, then push/tap in the metal wrapped seal......but I suppose not in that type of application. For front bearings, I have used grease w/o any problems.....but they are not holding back alot of hot oil under pressure.

 

I was suspicious of the seal with metal body from the start. I've never encountered them before. I suppose if you have a proper press tool which allows firmly and uniformly press the seal in, the metal casing should work. My suspicion is that as soon as you get somewhat out of square, you introduce a chance of leak. For some reason National seal had black rubber material on the working surface. I don't know if that is better or worse than the brown seals. I seem to recall that material type depends on application and the brown stuff tolerates heat better, while black stuff is stronger structurally. It is possible that some other applications would require a different style of installation. I'm just so glad to have this ordeal behind. That car owes me another 250k after this many attempts

 

Hunter.....you are so right, that ole Monty better give you another good stomping of at least 250k miles. Since you have the knack for solving all Mitsu issues, now tell me how to snap my fingers and make a rusty frame on one of my Montero's become solid and strong again.
Here she is, a rare 5 speed:




She looks great on the outside, but lift up here skirt and it gets scarey:






Bet these pics make you appreciate your oil-soaked frame on your Monty.
Im thinking of taking Wyle Coyote's suggestion and ordering some of that stuff from Acme........I think its called "Instant Frame", which is pretty much the opposite of the famous Acme "Instant Hole". Ha ha.

 

Dang, that's some serious rust. I think your PO used Acme "Frame-be-gone" on it few times or something like that.
If the rest of the frame is like that, I think that specific frame much be beyond saving. Two approaches come to mind:
1. The easiest and likely the best option is to find old (internally destroyed) Montero amd quite literally - swap frames. The problem is - knowing you, you'll fall in love with it and keep it too... How about putting a call out to several junk yards that part cars? Tell them you're looking for a frame. They might be able to locate one somewhere not too far away. Heck, even if it's out west here (your best bet for non-rustu one), road trip it to bring it home. Then just set the body on it. The only thing you have to confirm ahead of time is if multiple years used the same frame design/shape.
Option 2 - pull the body and make a new frame from scratch. There are places that can do this, but that's $$$. Likely that will cost more than trying to find a donor frame.
Option 3 - (along the way of option 1), do you suppose old Mitsubishi pickups used the same or similar frame with Montero?

Of all these, I think a direct frame swap is best option. Even if you have to make/modify some ctossmember, it is still going to be the closest thing to the original.

 

Hunter......Yep, those are the options, none of which is a "simple job". I watched a video of a mechanic doing a frame swap on a Toyota 4x4, and I think his total hours were over 100, and he does this all the time, and has huge floor lifts. In the case of this rusty Montero, the worse rust is right around the rear axle and behind......so, I had been thinking about attempting to weld new "L" pieces of metal around the old frame. Another idea is just replacing the back half of the frame with a doner......that would be alot easier (I think) than replacing the entire frame. I will have to decide at that point in time when I have the time for that project.

Funny about what you said......I will find a "doner" Monty to steal the good frame, and not want to tear into it, but save it also. Its hard to sacrifice a decent set of wheels.....yep, my pop grew up in the Great Depression and passed down alot of his "saving" mentality. (He is almost 100 yrs old, and is like that Timex watch......takes a lickin, but keeps on tickin.)

Regarding buying a used frame from a salvage yard, I think I can find an old Monty with a good frame for about the same price as just getting a frame.....plus, I will have a ton of parts to boot. I think the same frame was used on these Monteros from 1991 - 1999, but I would have to confirm that. I think all the Mitsu. trucks used smaller frames, and not as hefty....but I could be wrong.