superdylan

Well, I understand hydraulic pressure now. So, I'm in the process of taking my car apart to find the engine leaks and fix them. I am not planning to do an engine overhaul or top end rebuild. I just want to find the simple gaskets and seals and replace them.

I was looking at the bolts on the engine timing chain cover (driver side) and found some oil around them. So, I decided to pull one of the bolts and crazy half-moon washer. To my amazement, oil started pouring out of the hole. I then decided to put the bolt back into the hole and as the title states, there was oil in the bolt hole. As I threaded the bolt back into the timing case, the back side of it blew out. (Sounded like a little firecracker!)

Now, I've got a little more serious issue. As I said before, I don't want to do a top-end rebuild or any major stuff on my engine. I've got a couple of questions.

1. Can I repair the hole by welding or doing something to make it last another 30-80k miles?

2. If #1 isn't possible, could I do a partial engine drop and replace the driver side timing case, gasket, bolt grommets, without too much trouble?

3. Should I just part out the car now and call it a day?

superdylan

Oh, the horror! Instead of sealing holes, I'm making them...

mojorizing

Are you sure it wasn't the sound of the cover cracking because you over torqued the bolt?

I find it highly unlikely that you blew out the backside of a blind hole by hydraulic pressure. Or, if oil was leaking out, then there's no way to build up pressure when you re-install the bolt.

You need to investigate further - have you actually removed the cover and seen this hole? If not you need to .....you won't drop all 11+ quarts of oil if you remove your chain cover.

mojorizing

Now that's a hole. I hate when I'm wrong.........

mojorizing

Aren't those bolts actually studs? If they are ( and I believe they are) this is how I might do it:

Remove cover
degrease hole and internal threads
remove nut from stud
use locktite sealant and reinstall stud
degrease exterior and prep with sandpaper
apply JB weld to exterior of hole
reinstall cover

what you think? I'd avoid welding for fear of warping the flange where the cover sits.

superdylan

I was thinking about JB Weld or something like that. What about oil pressure? Will JBWeld hold up? Would a professional welder be able to actually weld that hole closed?

bobster964

I've repaired aluminium castings with 'Devcon Aluminium putty'. It's so good it is machineable when set. If you do a good job of finishing the back face afterwards you won't even see the repair.

I've had a pack for more years than I can remember and wouldn't be without it.

Found a link below. Check it out I think you'll be impressed what it does.

I wouldn't go anywhere near it with a welder!

http://www.itw-devcon.co.uk/index.ph...inium_putty_f/

Good luck.

RSGulp

JB Weld will fix it - just make sure the hole and area around it is really clean. The repair will easily stand up to oil pressure and the stuff is petrol and oil resistant.

In my student days I repaired a crack between a valve guide and a spark plug hole on a VW Beetle cylinder head with JB Weld. And the repair stood up to the heat and pressure of internal combustion! The car ran fine for another 60k miles before I sold it. ...and probably still running fine now.

superdylan

Thanks for the help guys. I just remember that as soon as I saw the hole blow out the back, dollar signs were multiplying in my head. I'll look into both the devcon and the JB Weld.

Any particular JB Weld? I think they have different types..

RSGulp

This is what I've used before: http://jbweld.net/products/jbweld.php

Indycam

I don't think you have to do anything . There should be no oil getting to the threads if the seal works correctly , therefore the bolt should not leak oil . If it does leak oil a little Aviation form a gasket on the threads should do the trick .
http://www.permatex.com/products/aut..._Sealant_a.htm

NineMeister

The assembly consists of a shouldered stud, rubber seal, dome washer and locknut. In 99% of engines the nut siezes onto the stud and on disassembly the stud unscrews from the timing case - as in the situation above. The refitted the stud/seal/washer/nut assembly will happily seal the front of the timing cover so the only problem you have is oil leaking through the tapped hole in the case down the threads of the stud, hence the stain on the back of the timing case.

I strongly recommend that you do not disturb the assembly by removing the stud again because you are liable to cause the second issue that these parts have, namely stripping the thread in the magnesium chain housing. Thus to effect a suitable repair on your case, with the engine cold (so the engine oil is thicker) clean the back of the hole with brake cleaner or other solvent and just fill it with JB weld. That should do the trick nicely & save you getting oily (again).

superdylan

So NineMeister, were you peeking over my shoulder while I was doing this? You are exactly correct in that the nut was stuck to the stud and it all started to come out!

So, you say to not mess with the bolt again, but I'd like to replace my timing cover gasket and the rubber seals on the studs. Is that still possible?

92silver964

Interesting thread. You can create very high hydraulic pressure at the bottom of a blind tapped hole if the thread class is good, the trapped oil volume is low, and you crank the torque wrench hard and quick (before much leakage occurs). Also, why would you use a steel-based adhesive filler compound for aluminum materials? Someone above recommended an aluminum filler Devcon product that looks suitable. Good luck!

Jon Hansen

If worse keeps getting worse and the internal threads are stripped, you could essentially through bolt this "leak" now. It looks like there is plenty of room for another nut / washer / o-ring / sealant on the "back side".
This wouldn't be a proper fix, but more of a race car fix to be done in a pinch.
If it works though, hey why not?