SkinnyBTN

I could really use some help. I've got a 96 that has had the head gasket replaced twice and is still leaking oil. It runs great! I mean really well, but it has a good bit of oil leaking from the head to block mating area. The first shop I had do the work said they decked the head and installed all new head bolts. After looking into it two different times and it wouldn't quit leaking oil I started getting the runaround and became a big argument about the $ situation. I finally gave up and took it to another shop whom I heard was much more knowledgeable and reputable and so far have been every bit of what I heard they were. The second shop so far has removed the head and checked it in the shop. It was not within spec and appeared to have not been decked as we suspected. They (2nd shop) had the head decked and installed a new gasket. The bolts seemed good so we reused them. The truck runs great aside from the oil seeping out between the head and the block. The mechanic at the 2nd shop thinks it could be that the head bolts have stretched. What do yall think? I hope all that makes enough sense. If you have questions please ask. I could really use the help I've got quite a bit of $ in this thing at this point. Thanks!

13ALPHA

If I was paying to have that work done on the head, a second time especially, I'd just go for new studs.

SkinnyBTN

Im going to put in studs if I feel the prob is the bolts. Im just tired of putting money into it and it not fixing it.

SkinnyBTN

So if the bolts are stretched is it common for the cylinder pressure to hold fine but allow oil and water to seep out between the mating surface?

13ALPHA

Good question, I would guess there is margin for a small leak before the cyl. pressure drops but I am just guessing, sure someone here knows....

Tate

Where is it leaking from? Have they checked to make sure its the right gasket? Have they checked the block for flatness?

SkinnyBTN

This is kinda long. I apologize. Since the previous attempt to replace the head gasket failed and we were not sure whether the previous shop did things correctly. Like even deck the head. It didn't appear that it had been decked and was quite "warped". The 1st shop said that they decked the head and installed all new head bolts, but it doesn't appear that they actually did either of the two. The first shop actually called me one day saying that they couldn't get the gasket to line up then called back and said they figured it out. I have no idea what was giving them trouble. I got the truck back and drove it for 1 day and was thinking something was wrong cause I felt it looked as though coolant was getting into the oil. The truck ran great and has throughout this ordeal. The second day I hooked my business trailer to the truck and headed out to work. Within an hour there was coolant and oil pouring out the sides of the head to block mating area. I took it to the shop and they tried to tell me everything was fine that it was a small coolant leak in a hose. Not sure how they thought they could get away with that. Thats when the arguing started and I found out from other folks that I was not the first person to get screwed royally by this business. So, I'm still working on the $ situation with the first shop. The second shop whom I was told about from a fellow diesel enthusiast builds pulling trucks and has a shop in a little town not far from me. I took the truck to them they tore the head off and meticulously inspected everything. The head appeared to have never been decked and was "warped" we had the head decked at a local shop that he always uses. The block was fine and the head bolts were checked for stretch and drop tested and were good. I should probably installed studs or at least new bolts, but have too much invested in this already and cheaped out. The mechanic felt they would be fine though. He put it all together and idled the truck for 3hrs. then ran the dog shnot out of it and it held fine. I picked up the truck and drove it home. next morning I hooked my business trailer up to it and headed out. Bout an hr into the day and I found a puddle of oil under the truck. Popped the hood and found the oil to be coming from the head to block mating area on both sides of the engine. The shop sent a tow truck and hauled it back to the shop. We havent had a chance to tear into it, but he said he's never seen one do this. The truck runs great and has full compression. It just leaks oil like crazy! That is everything I know about it. Any ideas? Thanks for the input.

Polaraco

Did anyone magnaflux the head? Maybe there is a crack. If it's in an oil gallery, it can be sealed.

It's unlikely the block is not true, unless it really overheated. Remember, they're never 100% anyway.

Are you SURE it's the gasket and not something else? Seen that before too

SkinnyBTN

No I'm not. Thats why I'm asking for ideas cause I'm stumped. I don't think it was magnafluxed. I do remember the guy at the first shop saying they had it magnafluxed, but I highly doubt it. I think we will probably have that done this time, but if it was a crack in an oil galley would it cause it to leak on both sides? I was kinda thinking maybe it was somehow getting into the exhaust then leaking out the exhaust manifold to head mating, but that wouldn't explain the leak on the intake side. Plus I'm not getting excessive smoke or smelling alot of burnt oil. What other situations have you seen. What should I look for?

Polaraco

Actually I was thinking valve cover or the oiling line to the turbo. But I can't see it either.

Wash the engine down with some engine cleaner. Get it good and clean. You know how fast it leaks. Keep checking it. When you start to see oil, trace it to the source.

Here's a thought. . . If the whole bay is soaked, look at the fan and the front of the motor. It could be a front seal or a front gasket. Fans tend to scatter stuff around quite a bit

Look for the black spots on the exhasut manifold. You'll see streaks there if there is enough. . . trace them back in the logical direction. Think of rain hitting the windshield while driving.

How much oil are you losing?
How fast does the leak show up?

Pictures help

SkinnyBTN

Yea pics would help but the trucks at the shop right now. The engine bay isn't soaked to the point I cant see where its coming from. Its coming from the head to block mating surfaces. Its just seeping out. After running for a while, before I noticed the leak, it got the sides of the engine pretty wet and the tranny. Everything else in the engine bay is very clean. We just can't figure out why the thing wont seal the oil and water but will seal the cylinders.

SkinnyBTN

Figured I'd check back once more and see if anyone has any ideas. We cleaned the engine up extremely well. Wish it always looked this good. Started the truck up and let it idle. It doesn't leak at idle, but once you start to drive it and get a load on, it starts to seep out. Its definitely coming from the head gasket. The majority is coming from the back of the engine/head. It still runs great though. Starts as it should, sounds normal, idles normal. I don't get it. I'm guessing it has to be the block, but if the block is out enough that the head gasket won't seal why cant we see where its out when we check the head? I tried to take pics, but where its leaking I can't get to with the camera so you can make out whats going on. Any ideas are greatly appreciated. Thanks!

j-fox

Are they using a Cummins head gasket or other???
Isn't the HX 40 spec'ed to about 35-40 psi?
Are you letting it warm up before you hammer it?

SkinnyBTN

Well to my surprise he went ahead and redid the head again. I stopped by yesterday evening and he was letting it idle. Said he couldn't stand for the engine to be kickin' his , lol! For whatever reason it doesn't seem to be leaking yet. We'll see how it goes. Thanks for any and all ideas and comments. If it starts to leak I'll update.

BC847

As an FYI:


There are six oil passages that run from the block to the head (on their way to the rocker-arms of each valve).

The oil comes up through the block, and at the block/head interface, runs through a passage in the head-gasket, and up through the head-bolt hole in the head.





At the top of the head, where the rocker-arm pedestals meet the head, there is a passage in the base of the pedestal that carries the oil from the head-bolt hole in the head over and into a passage in the pedestal.





From there, the oil goes to the rocker-arms and valve-stems.