Excessive valve cover gasket leak.

[SUMMIT CRUISERS]

Here's a thought if you can get to it from the side:
http://www.locknstitch.com/Repair pdf files/Aluminum crack inspection and repair examples.pdf

Look at page 37 and down. Not familiar with the procedure but it looks like it would work. May be easier than doing a new head. If it doesn't leak too bad, I would leave it alone.

 

[4G63 POWER]

That's a good idea. Or you could put a few bags of ice on your valvetrain and get everything really cold. Then have an expert aluminum welder give the crack a once over.

 

[bmw635]

I don't think the LocknStitch will work as it's along the thin wall of the head. I'll ask my friend if he can weld the head since he has the alum tig welder and certified. Thanks.

 

[clownmidget]

If you read through the thread I posted there is some good advice

It is not likely from over tightening anything, or a bad machine shop or whatever. And it is a fairly common problem that most folks just wouldn't notice when most of the seals are leaking on a 20 year old truck with 200K miles...

From my experience, you won't find anyone willing to touch the head while it's in the truck with a welder. It would make sense to do this if it was out on a bench but that's not the case. From talking to Robbie (powderpig) and what I read in that thread, I eventually took the valve cover off, cleaned up the area very very well with brake parts cleaner, and then used a small burring bit on a dremel and roughed up the crack both on the outside and inside, and used a 1/8" drill at the very end of the crack to try and prevent it from running any further. Once I did that, I cleaned it up again, and then used Toyota FIPG to cover the entire crack and the two small indentations I made at each end of the crack (inside & outside). I let that sit overnight, put the valve cover on with a new gasket, used blue thread sealant on each of the valve cover bolts.

Since that time I've also run a turbo with ~10 psi boost and have not had any leaks.

 

[bmw635]

Got a line on a used head so should I get that and rebuild the head again or try welding current recently rebuilt head ? I'd rather try to weld rather than FIPG or JBweld. Just rebuilt engine at 275k miles and now it's 283k and I want a good fix with no leak. Thanks.

 

[bmw635]

This low heat Alumiweld rod welding from Harbor Freight with propane or map gas might work. I'll try diy tomorrow and report back.

 

[skhochay]

Dam, you're right! I see a faint line from the crack on top all the way down to the white tip manifold stud.Is this a common crack from overtighten stud?

No welding or JBweld possible? Engine runs fine. Time to look for another head- anybody got a lead on head for 95? Thanks.

I have the same, same spot. There is nothing that I was able to do I have tried some options, because the crack is very small take a sponge and place between pipe and the head, the sponge will soak in the oil, so it is not going on the block each time when I change oil I just change the sponge to new one that about 5K miles, crappy solution, but works the engine stays clean. If you find any other ways to solve it let me know. One time I was thinking drill it and put small plug - same that on the front on the engine, but then I said to myself - who gives a rat about it

 

[mkmarz]

Dam, you're right! I see a faint line from the crack on top all the way down to the white tip manifold stud.Is this a common crack from overtighten stud?

No welding or JBweld possible? Engine runs fine. Time to look for another head- anybody got a lead on head for 95? Thanks.

Where are you located? I was trying to sell one to another mud member, but he's been MIA.

 

[bmw635]

My sig say OC, S CA. Got a lead for a free head so I am good. Thanks.

 

[bmw635]

Well, consulted my certified welder friend and he said the 700F working heat to braze the Aluminum rod might damage the head gasket so I tried JB Weld today, will see how it will hold up whe n i start the car tomorrow until I get another head from a local mudder to rebuild that then swap. This is my long trip, expedition vehicle so dont want field failure. Thanks.

 

[clownmidget]

I have found JB Weld to get too brittle & not tolerate the higher temps well at. Good luck with it though. Whatever is in the Toyota FIPG though is very good at adhering to metal & staying really pliable with heat for a long time.

That area has essentially no pressure so other than the oil leaking out or the crack extending enough for structural problems it shouldn't be an issue. I've got almost 70K miles on mine since the rebuild when that crack was noticed spanning UT to ME to FL so I think you'd be fine until you have time & resources to replace the head.

 

[scottryana]

They make a high heat jb weld....... But if you have access to a free good used head, I would get it ready.

 

[bmw635]

Update: JBWeld is holding off the leak on the side but it's leaking past the crack on the gasket mating surface. It leaks about 2-3drops after idling for 1/2 hr so it's significantly less than before.

I'll get a spare head to rebuild then swap when ready. Thanks to all the tips.

 

[skhochay]

Update: JBWeld is holding off the leak on the side but it's leaking past the crack on the gasket mating surface. It leaks about 2-3drops after idling for 1/2 hr so it's significantly less than before.

I'll get a spare head to rebuild then swap when ready. Thanks to all the tips.

I told you want to do my solution is very real Land Cruise 80 using wool felts on front knuckles to absolve extending oil , so I am not off when I use a sponge between pipe and the block - works like a charm, same consent.