Need Engine Gasket info ?

[Watchman]

On my 93 explorer sport with EGR (CA), I've got an oil leak that I believe is coming from the rear of the engine. I also believe that the oil pan gasket is leaking as well. My question is how many different engine gaskets or seals are there on this engine.

Is there a list posted on a thread or sticky ? I couldn't find one. I was going to pull the engine soon, and was going to go thru the necessary gaskets. I already did the head gasket this last summer and also replaced the UIM, LIM, and valve cover gaskets. Just need to know the other engine gaskets/seals. Thank you.

Oh - it is an A4LD trans.

 

[natenkiki2004]

UIM, LIM, Valve cover and heads aside...

Oil pan, timing cover, water pump, front & rear crankshaft oil seals, oil pump, throttle body, iac...

I think that's about it. Do the timing cover and oil pump gasket before you do the oil pan gasket. The only oil pan gasket I found was a cheap rubber from Felpro. No silicone or anything. What I did, and it looks good so far, I used a little Permatex Black to hold the rubber molded gasket in place on the pan, very thin amount. You want the primary sealing to be what OEM specified (I like to think they knew what they were doing). Then, on the outside of that rubber seal, I ran a bead of Permatex Black as a backup seal.

Also, be sure to use the green (it's been called teflon) OEM timing cover gasket. If that ever has to be done in the future, using this type of gasket means the gasket won't flake and you won't have to scrape it off the sealing surfaces. I used some Permatex Black on one side (engine side) to hold the gasket in place while I got the timing cover ready. I did not use any RTV on the timing cover side because there is a channel that runs on the outside of where the coolant flows through. This channel should be clean as it allows any leaking coolant to exit the engine, rather than leak into the oil pan. RTV may clog this area and in rare circumstances, cause problems.

There's a thread on here that talks about having to heat the harmonic balancer in an oven to get it to expand in order to re-install it, I didn't have to do that. I actually had a much harder time getting the rear main seal sleeve to go on straight than I did with the harmonic balancer.

Also, there's a triangle shaped gasket in the timing cover set offered by Felpro. You might think that's for the timing chain tensioner, it's not. The tensioner has no gasket. That triangle gasket is actually for the oil pump.

 

[FR-425]

Full set:

https://www.rockauto.com/catalog/x,carcode,1119620,parttype,10392

Of course you may want to get the rubber valve cover gaskets instead of the cork, and the lower intake conversion to 2 piece set.

Rock Auto has those too..

It doesn't appear that this kit has the upper intake either.

 

[Watchman]

I appreciate the info - What about the front and rear crankshaft seals ? Is the rear crank shaft also know as the rear main seal ? I think I am going to focus on the oil pan gasket and the seals that deal with oil. 35K miles ago I had a shop change all my gaskets from the UIM down to the head gasket, and the timing cover etc. But unfortunately there was a leak in the back of the engine (is this the rear main seal or rear crankshaft ?) that he could not get to seal properly. He changed the gasket (from Napa) 2X. He even sent the gasket back to the manuf and they him there was nothing wrong. The whole point of my having him replace all the engine gaskets was to maintain the engine and vehicle. But he couldn't stop that one leak. Finally gave up. So, now I want to address this since you guys have done this and understand the issues. I really appreciate your help here.

 

[natenkiki2004]

Rear main seal is the same as crankshaft seal, there's only 1 there. Take a look at this:
https://dl.dropboxusercontent.com/u...Explorer/Pictures/Engine Removal/P1020146.JPG

It's tough to say where it might be leaking from now. You say the mechanic replaced a gasket twice, was it actually a gasket or was it an oil seal?

Mine leaked from the rear of the engine, mostly in the bell housing. I thought it would be the rear main seal since that's exactly where it would leak from. But it turned out to be the oil pan gasket that was leaking out there. Take a look at my picture, the rear main seal is the brown one while the oil pan gasket is behind the grey sealer. I ran a bead of Permatex Black on the outside of the oil pan gasket as a secondary seal in case it fails in the future.

Those are really the only 2 things in the back of the engine that would leak. Unless it was leaking from the valve cover or lower intake manifold and running down the back of the engine. Unlikely, since you had those replaced, but possible. You should be able to get underneath and check with a flashlight, if it's dry up top then it's one of the lower ones.

Just for reference, this is what mine looked like underneath:
https://dl.dropboxusercontent.com/u...rer/Pictures/CameraZOOM-20140929102113950.jpg
After I wiped it clean and started it up:
https://dl.dropboxusercontent.com/u...rer/Pictures/CameraZOOM-20140929103754336.jpg


If I had to guess, I'd say your mechanic had problems with the rear main seal. They can be tricky in some circumstances. The oil pan gasket is pretty much a no-brainer. The rear main seal might need a sleeve installed. I used a SKF 23823 (I believe). The sleeve was tricky to get started and nerve-wracking to get seated down. You only get 1 shot and it would really ruin your day trying to get it back off. I was tapping it in and double-checking seal depth, where the lip would sit and how far in the seal had to go.

 

[Watchman]

Wow - I really appreciate the pics Nate - I will try your method - clean it up then start the engine and look for the leak. Also, it has been 4 years since that engine gasket work was done, and I can't remember if it was the rear seal or the oil pan gasket. I will try to contact him.

I have never pulled an engine. I have watched a couple of You Tube videos, but some of the important details, especially disconnecting the engine from the trans during removal and then re-mating for installation. Any advice or direction will be appreciated. I really want to restore this truck - it's got rusted rocker panels which I would also like to do myself - but first I want to get the engine sealed up. Then the cosmetics. Thanks again Nate.

 

[Watchman]

Another question - on your first picture, is this the back side of the engine as it faces the firewall ? I see on the LH side, what looks like a long bolt - does this attach to the oil pan ? Very strange, with spring clip ? I'm having a problem by looking at this photo visualizing the back side of the engine block here.

 

[natenkiki2004]

Yes, that's the backside of the engine, upside-down. I have no idea why that long bolt is there. Maybe to remove the oil pan with the trans attached? That would be a weird way to remove it.

I have all my documents/pictures and more on my Explorer here:
https://www.dropbox.com/sh/zud28082dubxeze/AADguWM08B-BoL4sjisw9y9Xa?dl=0
You can go into Pictures and then Engine Removal for more.

A lot of people would say you can leave the engine in and just remove the trans to get at the rear main seal. I'm sure it CAN be done but after knowing what I know now, I'm glad I pulled the engine. I had never done anything like it before (hell, before getting the Ex, I had never done any work on vehicles) and didn't know the entire process. Luckily I had some knowledgeable people walking me through it but I did the majority of the work.

All in all, it took me about a week. I took 2 days in the middle of the week off for something, I don't recall now. So, in reality, 5 working days. I did a fair amount of stuff and took my time. I'm sure a few people on here can drop a trans or remove an engine in a matter of hours.

The hardest parts for me were getting at the bell housing bolts. The previous owner had dropped the trans twice and the second time, it was hastily installed, the bolts were ran in real quick with an impact gun. One got stripped in that process. An impact gun will be necessary to remove the bolts, along with an assortment of extensions, wobbles and universal joints. 2 bolts by the exhaust took almost 2 feet of extensions. I didn't bother dropping the exhaust and I had to go around the catalytic converter.

Another stressful time was trying to get the engine back in, getting everything lined up. You have to fight the motor mounts, torque converter studs and the 2 protrusions (ears?) on the transmission bell housing. They all have to line up. It took the 3 of us a couple of tries to get it right. We were so close the first time and something shifted and it all just fell apart, tried it again for another hour and nothing went right so it came back out and sat on the floor overnight. Came back the next day and still couldn't get it right so it came back out again. Adjusted the chain on the hoist, got a new plan of attack and it went in, slowly. I found that you have to lower the engine enough to get the flex plate into the bell housing, then you can orient for the torque converter studs. Once the studs are close, you can align up the engine & trans and slide it into the alignment pins. See here, on the left & right of the flex plate:
https://dl.dropboxusercontent.com/u...Explorer/Pictures/Engine Removal/P1020086.JPG
There's 2 studs/pins/dowels/whatevers that stick out and help seat the engine on the trans. Once the torque converter studs are aligned to the flex plate, align the engine & trans up and hopefully the torque converter studs will poke through enough to get a pinch nut on there. If it does, get one on and rotate the engine and see if you can get another one on. If the engine doesn't want to rotate easily then something is binding and you may have to jostle things. Once the torque converter and flex plate are happy and the pins are holding the engine & trans together, run the 2 bell housing bolts at the top of the engine in to hold it and seat the engine on the motor mounts. I opted to replace my motor mounts and I'm glad I did, the OEM ones were flexible while the new ones were so firm I thought they were solid steel. The alignment pins on the motor mounts weren't perfectly straight and made things difficult to align. This was one of the hang-ups that caused problems earlier when dropping the engine in. I took an angle grinder and made the alignment pins on the motor mounts pointed so the engine would fall into place easier. You'll see what I mean when you look at it in person. Once everything's seated and happy, start piling crap back on the engine in the way it came off.

I opted to do the cam chain assembly (sprockets, chain, tensioners) but looking at the OEM one with 225,000 miles, I don't think it was fully necessary. It depends on your vehicle's history too but I know mine had been neglected in the past. I took pictures of the chain, tensioners and sprockets, you can see them in the link above. I also opted to do the core/frost plugs. I don't think they needed to be done either but they did have corrosion and I wanted to install a block heater anyway. Anyone that installs a block heater in a first gen Explorer without removing a LOT of stuff would be a miracle worker.

Hope this helps It is a scary idea but if you have the tools, place to do it, and someone knowledgeable to help, it is very doable.

 

[Watchman]

Nate - amazing pictures. I appreciate your taking the time to go thru this. I don't have access or funds right now for air tools, compressor, etc. But I really want to look at doing this later this spring when the weather is better. By the way - did you stop all the oil leaks ? ie, from the rear crank, and oil pan ?

 

[natenkiki2004]

An impact gun is an absolute must. I used a wrench in areas where I thought I could get away with it and ended up rounding some bolt heads. Got the impact and out they came. Once you get one, it's an amazing tool that you'll wonder how you lived without it. For my project, I borrowed a friends. However, I recently bought my own, an Ingersoll Rand 231C. Yea, it's made in China but for the $110 cost, it'll beat the pants off of anything Craftsman.

I can't say for certain that my oil leaks stopped because a few things happened. When I was reassembling everything, I put a T pipe into the factory oil pressure sender so I could split it and run a gauge along with the dummy one in the dash. Only after I put everything back together did I realize that I didn't even hand tighten the fittings for the sending units, I had only mocked them up. With the radiator, power steering and all the other stuff in the way now, it's almost impossible to get hand tools in there to tighten it. I know oil is leaking there, it's wet (but not wet on the pan) and is dripping down that area. That's problem 1. Problem 2 is that I didn't buy gaskets for my valve covers, because I know I'm taking the top end apart to do the LIM gasket and pushroads & rockers. I used RTV on the valve covers and it's not a perfect seal. That plus the fact that my LIM gasket seeps somewhat, that's a questionable area in terms of leaks. Finally, there's been drips at the bell housing. At first this made my heart drop but looking at it closer, the drips are almost black while the oil in my engine is new and amber. The transmission fluid is pretty new too so it's not that either. I really need to get underneath and look around, it might just be assembly residue because lots of PB blaster was used, especially when I ran a tap into the engine block for the bell housing bolts. There was also a mess from priming the oil pump and flipping the engine around so many times. I don't have a garage or dry and warm place to look at things carefully.

2 other things I'm wondering too are, I know I slightly overfilled the oil so maybe it's unhappy with that. Also, my LIM gasket is seeping coolant, maybe it's seeping oil into the intake too.

Bottom line is, the front of the pan is bone dry and while there's a drip or two at the bell housing, it's not absolutely covered in oil like it used to be. I've put 350 miles or so on it since the work and have dropped maybe 1/8" on the dipstick. Where before, at 400 miles, I lost over 1.5 quarts and saw the "check oil" light 2 or 3 times.

Take a look at this:
https://dl.dropboxusercontent.com/u/464376/vehicles/1991 Explorer/Pictures/P1020192.JPG
Bone dry pan. But see at the top right, the brass T, it's wet up there. I may just leave it until I get the LIM done, when I'll have the radiator removed (fan clutch needs doing too) and take care of all that stuff in one go.
Here's the bottom of the pan:
https://dl.dropboxusercontent.com/u/464376/vehicles/1991 Explorer/Pictures/P1020194.JPG

I'd call it fixed but a few things need checking out, the work never ends

(sorry for the rambling)

 

[Watchman]

Wow - that was a big job. I do have access to battery tools. So I might use them.

BTW - I just checked my TPS on a voltmeter. I got 1.03 V at idle, then when I throttled it up, I got 2.64V max - most blogs say 4-5V. I'm still chasing MPG issue on the side. Still only getting 15-17 on the hwy - before parking this after I bought my Corolla, I used to get 20-22 all the time. When I first start it up it shoots up to 1600-1800 RPM before settling out at 750. After engine warms up, pulled harness of IAC (cleaned and checked 2 months ago) - no change in RPM, so I'm thinking TPS.

 

[natenkiki2004]

That TPS should be more, definitely. You won't get 5v but pretty close, at least 4.5 if I remember right. It should be perfectly smooth from 1v to 4.5v. Rotate the throttle at the throttle body directly, no cables.

 

[Watchman]

The highest it would go was 2.64V. It went up smoothly, but stopped there. I will try again this weekend when I have time ... Thanks for your help Nate.

 

[natenkiki2004]

Just to be clear, you are manually rotating the throttle plate by hand, not with the throttle cable or pedal? When it stops at 2.64v, are you able to rotate the throttle plate further? If so, it might just be a dead spot. If not and that's wide open throttle, there might be issues with your reference voltage or wiring.