oilpan, gasget, leaking

[Thomass]

two weeks ago, I did some work on my rig, because my oil-pressure went down and the engine temp went up

http://www.xjtalk.com/showthread.php?t=4806

I had the pan removed 3 or 4 times at that time, because the gasket on the tranny-side, didn't close good enough.
Finally it has been for nearly two weeks leak-proof. and I was happy.

Today I drove up to the airport, to do some work, and I noticed that there was again a leakage.
when I drove back home I even created a smoke-curtain on the highway caused by the dripping oil on the exhaust.

My oil-pressure was within OEM specs, as was for the coolant temp.

the last time I fitted the pan, it was in combination of an rtf special for the oil-pan and the original gasket.
I also did check if the pan was warped, damaged or in other bad condition.

all was fine.

So what can make the gasket to be pushed away, when the oil-pressure is normal and had the right amount. There where no lose bolts.
it just leaks right at the lowest point at the rear end of the engine...

[default83]

just silicone the crap out of it. we used to throw the gaskets in and then silicone the inside of the gasket, bolt it on and silicone on the outside of it just for safety reasons:D

[4.3LXJ]

Those areas are a problem on many engines. Silicone is a good friend there. In fact, on the intake across the valley on my 4.3L Chevy engine it has no gasket, just 1/8" silicone for a gasket. That was GMs answer to a problem area.

[bluedragon436]

^^ Was going to be my answer as well... same tactic we use on some aircraft systems depending on what they are, if there is a small leak even after replacing all seals and verifying the matting surfaces are smooth and flat... is to fill in the gap with sealant of some sorts...

[bigjim350]

Did you replace the rear main seal when you had the oil pan off?

[XJRunner]

kinda a obvious one...are the bolts all tight? I had a pan leak and 5 of the bolts were loose

[Thomass]

Those areas are a problem on many engines. Silicone is a good friend there. In fact, on the intake across the valley on my 4.3L Chevy engine it has no gasket, just 1/8" silicone for a gasket. That was GMs answer to a problem area.

Again I will take the pan of, remove the old gasket and sealant.
I got my self fresh tubes of RTF, the kind you even can use under water heat resistant and oil-proof.
And just glue and bold it once again. Not today (it is 20:00 hours over here)


Did you replace the rear main seal when you had the oil pan off?

Yes I did so, together with a new oil-pump. If it is open, just for prevention, it is always better to replace this nasty elements.

[Thomass]

About this RTF/silecone, if i do not use the original Gasket, and just only the RTF, what is the best way to use this stuff:
1: put a worm of RTF on the pan and directly bold it to the engine, so it will glued the pan and the engine together.
2: put a worm of RTF on the pan, and wait a couple of hours to set, so there will be a one side bounding, like the original gadget. and when dry (stiffened) bold it to the engine. This way it is not glued to the engine but only pressed.

The pan is off,(there was no visible reason why it was leaking, and brought to an sandblasting firm who will sand it, straiten it again, checking for cracks and powder coat it (on the outside)

[4.3LXJ]

There is also some RTV that is called "The Right Stuff" that is supposed to be superior for use as gaskets.

[ice_cold]

I found that the sealant works great, but I have a habit of using a hammer and tapping the areas where the bolts go on the pan down. That way when your bolting it up, it has to pull the flange flush, giving a slightly tighter seal.

Just a thought.

[default83]

About this RTF/silecone, if i do not use the original Gasket, and just only the RTF, what is the best way to use this stuff:
1: put a worm of RTF on the pan and directly bold it to the engine, so it will glued the pan and the engine together.
2: put a worm of RTF on the pan, and wait a couple of hours to set, so there will be a one side bounding, like the original gadget. and when dry (stiffened) bold it to the engine. This way it is not glued to the engine but only pressed.

The pan is off,(there was no visible reason why it was leaking, and brought to an sandblasting firm who will sand it, straiten it again, checking for cracks and powder coat it (on the outside)

put it on there while its still wet, so it seals the pan and the block, probaly wouldnt hurt putting a little around the bolts as well.

[4.3LXJ]

I have done the same thing many times. You dimple them to the outside with a small ball peen hammer while supporting the outer edge.

[Thomass]

You dimple them to the outside .

??? Dimple, i do not know this word only as a whiskey :-)

Wat I've done so far,
yesterday eve i collected the pan from the sandblaster,
on my request the have welded on the bolt holes an extra ring (the holes where cracked a bit)
today i will "glue" it in to place. i have to repair the threat of the two bolds in front of the engine, (i did destroy it my self, by using an metric bold instead of an UNC :( )
So later today I'll hope the engine is leak proof again, and i can go for the weekend to the snow. :happy:

[ice_cold]

looking down at the pan, looking at its inside. You take a ball peen hammer and tap the bolt hole areas down a little bit. This makes the bolt flange area lower than the rest of the rail. When you tighten it, it will pull the pan real tight as the dimpled part pulls flush with the rest of the rail.

[Thomass]

Two days the rig was leak-proof, and now it is leaking again.
I've straitened the oil-pan and reinforced the spots where the bold-holes are.
I've sealed the oil-pan with an RTF to the engine,
replaced (just because) the 3 rubber seals in the oil-filter housing
Replaced the front oil-seal of the engine (the back one was replaced a few days ago)

Still it is leaking at the back of the engine, and it is engine oil.
The strange part is, the oil on the dip-stick is clean, but the oil leaking out of the engine is black, not as black as used oil, but far from clean.
I have been searching to the place where it would possible leak. But I'm unable to find this.
Tuesday i will lift the engine out of the rig, and put it on the bench, and use an UV colorizing oil tho find this spot.
Or, if any of you have other suggestions, to look for, I'll be very graetfull

[bluedragon436]

I would hope by doing that you would be able to find the leak... that is alot of work just to still not be able to find the leak. Did you try changing the oil pan at all, or just kept installing the same one??

[4.3LXJ]

Thomas, is your valve cover leaking and running down the back of the engine? That would give it time to pick up some dirt and stuff to turn black.

[Thomass]

Thomas, is your valve cover leaking and running down the back of the engine? That would give it time to pick up some dirt and stuff to turn black.

That was my first thought, but around the valve cover (as around the head gasket) it is completely dry (looked with an mirror ad the backside)
it is a little wet around the filter housing but that is not wet enough to say it is leaking, more sweating.

[Thomass]

I would hope by doing that you would be able to find the leak... that is alot of work just to still not be able to find the leak. Did you try changing the oil pan at all, or just kept installing the same one??

I used the same oil pan, but the last time I did brought it to an shop, who did straitened the pan, reinforced the area's around the bold-holes, it was also sandblasted and powder coated.
Also the engine side was inspected on uneven sections.

Tomorrow (Tuesday) I will lift the engine out, my most best shot to see where this ### faulty area is.

Taken out the engine will gif me also the chance to inspect the rest of the engine an do some small modifications

[Thomass]

I did demount the engine, and put it on a stand. cleaned the engine overall, so there was no oil (or dirt) on the outside.
I borrowed from a friendly neighbour garage an extension to fit to the engine so it wouldn't have to run without a load.
changed the oil and filter added a dye, and started the engine up.
it ran for over 40 minutes idling, there was no sign of leaking.
than i revved it up to 1500rpm, and still no leaking. than, I reved it up some more, and more, but still no leaking.
The engine back in the rig after cleaning the engine compartment, and made a test-drive around the city. Back in the garage it was leaking again... there was a lot of bad words coming out of my mouth....
It was pure engine oil, ad fresh (with some dirt in it) because under UV i could see the dye, also on the engine at the rear end, it was smudged all over.
Then i remembered I did build in an new oil pump, with more oil flow with the same pressure build-up.
Looking at the the way the engine was built in the rig, i noticed that the engine front was situated some higher than the back.
I fitted a sponge between the valve cover and the fire-board, and drove a bit around.
The sponge was drained with oil. so the leaking spot was found. replaced the valve cover, with an new (RTF) gasket,and after driving, it was still leaking.
after inspection the valve cover and keep it against a strong light i noticed a minor crack (very little).
After welding (TIG) and shaping this cover, the leaking was gone.
because of the new oil-pump, I got an higher oil-flow true the engine, and because the engine is in a kind of angel in the rig taking this all together including the velocity of the rig, the oil, came up higher in the valve cover, than normal.
So this problem is solved, (I hope) and tonight i will go skiing in the austrian mountains. i do deserve that.

Thank you to all for the suggestions, even if it did not solve the problem, it made me think different

Thomass

[default83]

I did demount the engine, and put it on a stand. cleaned the engine overall, so there was no oil (or dirt) on the outside.
I borrowed from a friendly neighbour garage an extension to fit to the engine so it wouldn't have to run without a load.
changed the oil and filter added a dye, and started the engine up.
it ran for over 40 minutes idling, there was no sign of leaking.
than i revved it up to 1500rpm, and still no leaking. than, I reved it up some more, and more, but still no leaking.
The engine back in the rig after cleaning the engine compartment, and made a test-drive around the city. Back in the garage it was leaking again... there was a lot of bad words coming out of my mouth....
It was pure engine oil, ad fresh (with some dirt in it) because under UV i could see the dye, also on the engine at the rear end, it was smudged all over.
Then i remembered I did build in an new oil pump, with more oil flow with the same pressure build-up.
Looking at the the way the engine was built in the rig, i noticed that the engine front was situated some higher than the back.
I fitted a sponge between the valve cover and the fire-board, and drove a bit around.
The sponge was drained with oil. so the leaking spot was found. replaced the valve cover, with an new (RTF) gasket,and after driving, it was still leaking.
after inspection the valve cover and keep it against a strong light i noticed a minor crack (very little).
After welding (TIG) and shaping this cover, the leaking was gone.
because of the new oil-pump, I got an higher oil-flow true the engine, and because the engine is in a kind of angel in the rig taking this all together including the velocity of the rig, the oil, came up higher in the valve cover, than normal.
So this problem is solved, (I hope) and tonight i will go skiing in the austrian mountains. i do deserve that.

Thank you to all for the suggestions, even if it did not solve the problem, it made me think different

Thomass

holy crap dude, lol, you have a lot more patience/time then i do. i would have left it leaking.

good job.
:thumbsup:

[ice_cold]

I would have replaced the dang thing by now! Congrats on your kick *** trouble shooting skills.
Now go skiing...now I am jealous....