Leaking below oil pan flange. 6bolt, wrong bolt size into pan?

[PewPew90Laser]

I've had the pan off a couple times and never got it to stop leaking until I finally sourced the leak.
Directly under the OFH there's a small oozing of oil that follows down the pan. Above the pan flange completely dry! Nothing's leaking from the block!
My oil pan is leaking out the bolt hole?!
It sure looks like it is. I'm using 8mm bolts all around, hardware store granted me new ones. Old bolts looked gross and some didn't match so I replaced them all with the "small bolts"
I just read that can cause oil leaks? What size are the normal bolts or what size can I run on that bolt? It shouldn't hit anything, timing belts aren't close.

 

[19Eclipse90]

The oil pan bolts are M6x1.0, (2) 10mm long under the timing belt, and (17) 12mm long for the others.

 

[PewPew90Laser]

is it common for oil to leak out the pan bolts if they don't have any locker or sealant on them?
I don't think I even used washers.
OOPS

 

[thomcasey]

My pan doesn't leak. Just using the stock 10MM bolts and gasket. Just a little RTV on the gasket to hold in place when installing. I don't remember any washers on the bolts.

 

[PewPew90Laser]

I'll pick up another pan, this one may have cracked. Will reseal with different hardware and here's the kicker!

I'm going to use an oil pan gasket with grey RTV on both sides of it. I'm not taking any chances on this one.

 

[steve]

There were two types of bolts used on 1G pans, the 90's and real early 91's used bolts with captive washers and the later cars used flanged bolts.

Remember than bolts aren't described by the size of the head but by the diameter and length of the shank. For the oil pan they are all 6mm and the ones with washers are either 10mm or 12mm long. The flanged bolts are 8mm and 10mm long.

When you seal the oil pan flange, both the pan and block have to be clean, dry and flat. You run a continuous 4mm bead of RTV around the pan flange in the center of the flange going around the inside of each bolt hole and install the pan within 15 mins so that the RTV doesn't skin over and not bond to the block.

Since the bead runs to the inside of the bolt holes the pan and block should seal before any oil can get to the bolt.

The pan bolts only get 4-6 ft lbs of torque and over tightening them can cause the RTV to be squeezed out and not seal.

Using a gasket with RTV almost insures it will leak. RTV used correctly alone will seal just fine.

 

[PewPew90Laser]

the gasket to block isn't leaking

it's coming out the bolt hole or the pan side flage is cracked or has a hole or something. The pan block mating surface is completely dry and so is everything above it.

 

[steve]

If you think it's a bolt leaking clean it and put some thread sealer on it to see if it goes away.

 

[PewPew90Laser]

I took the bolt out, wire brushed the flange and cleaned all surfaces with solvent.
I pushed some RTV into the bolt hole, spread rtv on the washer and threads and installed.
Waiting on rtv to cure, I'm in the northwest and the temperatures right now aren't the best for this.
I used grey rtv by the way it should hold up. Will post results thank you guys.

In all of my wrenching, nothing has told me to put sealant on an oil pan bolt....dsm are weird cars. So much fun though!

 

[steve]

In all of my wrenching, nothing has told me to put sealant on an oil pan bolt....dsm are weird cars. So much fun though!

You shouldn't have to but if it's leaking it's one way to solve the problem or find out if there is some other problem.

 

[PewPew90Laser]

The initial oil pan gasket install much have been botched. I used grey rtv and a gasket it must not have sealed 100% all the way.
I used grey rtv on the bolt and it didn't bind to the oil pan and leaked again but slower. I then used ultra black permatex and it sealed up tight. I shot some into the bolt hole and then on the washer and bolt threads. It's sealed up fine now.

 

[steve]

The initial oil pan gasket install much have been botched. I used grey rtv and a gasket it must not have sealed 100% all the way.

If you used a gasket and RTV instead of just RTV that would explain it.

 

[PewPew90Laser]

why would that make any difference?

Oil pan is leaking out the other side now. You may be onto something! Why would it do that though?

 

[donniekak]

why would that make any difference?

Mitsubishi didn't build 4g63's with an oil pan gasket. The manual calls for rtv ONLY. Any gasket is not a mitsu part, and as a general rule of thumb, it's rtv, or gasket, not both.

 

[PewPew90Laser]

Mitsubishi didn't build 4g63's with an oil pan gasket. The manual calls for rtv ONLY. Any gasket is not a mitsu part, and as a general rule of thumb, it's rtv, or gasket, not both.

yeah I got that but why not? An rtv'ed gasket is going to take up loads of imperfection and I want that.

 

[TSIfreek]

I really like the ultra black RTV. It seals up great

 

[PewPew90Laser]

I really like the ultra black RTV. It seals up great

Me too. I'm getting the fatty tube tomorrow and not messing around with the weird grey stuff.

Black or red I've never needed to use anything else!

 

[TSIfreek]

yeah I got that but why not? An rtv'ed gasket is going to take up loads of imperfection and I want that.

Yep you got it. Its just a pain to clean all the old RTV off but its the best way. personally what I do it put the rtv on the pan and then smear it around with my finger to get all parts of the oil pan. I have found doing it this way keeps the RTV on the pan rail evenly when installing.
Make sure the oil pan surface is not bent from taking the pan off also.
Another thing to do is make sure there is no dried RTV in the bolt holse as this will cause the bolts to bind and not thread all the way in.
The preperationn to the block and pan is the main things to get the best seal possible.

 

[PewPew90Laser]

I'm sick probably some nasty cold or flue strain but I'm going to get a fatty tube of ultra black and a wire wheel for happy fun cleaning time.
Will update when things settle.

 

[donniekak]

yeah I got that but why not? An rtv'ed gasket is going to take up loads of imperfection and I want that.

A gasket with rtv on both sides will not seal as good as a dry gasket, or just rtv. Remember, gasket, or rtv, not both. If your pan will not seal with rtv, it is damaged, or the surfaces were not prepped properly.

 

[PewPew90Laser]

My pan is belt a little I got it straighted out mostly but it's about 1/6" off across the whole length.

I took a wire brush and took the pan surface down to the metal. The block surface was scraped with a razor and both surfaces were cleaned with gasoline.

I used a can of permatex ultra black and the humidity has stopped me from dropping oil in it yet. It's 60's here and raining super hard right now. I'll let it cure the full 24 hours and post how many other leaks I have to fix.

I now see what you mean by either rtv or gasket. The grey rtv I used did NOT bind to the gasket at all. The gasket was easily removed and did not adhere to any surface. It merely sat between to surfaces of goo.

 

[steve]

I now see what you mean by either rtv or gasket. The grey rtv I used did NOT bind to the gasket at all. The gasket was easily removed and did not adhere to any surface. It merely sat between to surfaces of goo.

Did the RTV stick to the metal? There may be a wax in the gasket that inhibits the RTV.

 

[PewPew90Laser]

Did the RTV stick to the metal? There may be a wax in the gasket that inhibits the RTV.

It mildly stuck to the gasket and bonded well to the metal. I'm not sure what type of material was used in the gasket I don't really care they're terrible.

I took my pan off again because it was POURING oil. There was a gash in the RTV where I installed the pan wrong and hit the stupid main bearing loop thing.
I ordered a new pan because mine was destroyed from being off and on so much.

Also I got a fat can of ultra black RTV and went to town on this install. It worked! For the first time in six months the DSM no longer cries oil! There's been a handful of other issues but the oil pan was the main culprit.

Thanks for all your help guys.