Damned head gasket troubles

[jtl]

Looking for some opinions before I get drastic. Here is the situation:

- Bought a 91 na w/156k miles with the telltale smoke on startup
- rather than just replace the seals I decided to remove the head a cleanup the valves, head, etc.
- had the head machined as well as it was apparently 0.005" out of spec which is on the high end
- put it all back together again with new gaskets of course and found that coolant was spilling into the oil
- said "Shit" a few times to myself and ripped the damned thing apart again thinking I didn't clean the block good enough or something like that
- cleaned the block up very nice and reassembled again only to still have the same problem
- Said Shit and other unspeakables a bunch more times
- I've done this before on other cars and never had a problem but decided to get a Toyota mechanic to come out and do the whole job again
- now he did do a few extra things on cleaning and prep as well as installation that made me feel somewhat positive
- started it up and said all those nasty words again

This is starting to get expensive with new gaskets and head bolts everytime (dmaned stretch bolts). I'm beginning to think it has something to do with the machining that was done to bring it back to spec. maybe that somehow screwed up the mating to the block. The Toyota guy measured both the head and block prior to installing and did gap checks with a 0.002" feeler guage and found it tight everywhere. So it beats the hellout of me what's going on.

I'm now pondering the next phase but was looking to see if someone had any other ideas to what I'm contemplating before I go ahead. ANy thoughts would be appreciated.

My next phase will be either one of two things;

1 - find some kind of cement that will permanently bond (and seal). I know a lot of you will groan and look at me sideways and say I'm nuts but if that is not a viable option, then I go on to option 2

2 - find me a used 5SFE and drop it in and take the old pain in the ass out.

Any thoughts.

[cantalibre]

Silly question, but I guess you're torquing up to the correct specs?

[jtl]

Yeah I did twice myself to the right spec and sequencing (everything by the book). And so did the Toyota mechanic as well. Didn't seem to make any difference.

[cantalibre]

Can't see why the mating shouldn't be fine, assuming head is skimmed properly and gasket is okay. Are there any splits in the block itself, which might weaken the joint?

[toyotaspeed90]

what sort of gasket are you using? some of the cheaper brands might have the holes off just a bit to match many other years & whatnot....

it's possible that if the car in the past was overheated (and possibly why the head was so far off) that the block would be warped just enough to cause the problem....

also there's a chance that the oil cooler itself is causing the problem, not the HG.... are there any tracers on the HG when you pull the old one off? check to make sure that everying on the HG seems to be mating up right.

always try to check obvious things..... friends and I have found ourselves toiling over why something is doing what it is only to find a blown fuse or bad ground wire and just assumed it was already checked.....

[jtl]

Thanks for all the ideas guys. I have used a head gasket from Toyota everytime ($80 a shot for that alone and then $30 or so for new head bolts everytime as well - stretch bolts).

I had the Toyota mechanic check the block over for cracks and he couldn't find anything. I am interested though to know about why it might be an oil cooler problem.

When I had the head machined, the guy thought that it could have been out of whack because of an overheat in the past. So maybe it kind of warped everything (head & block) locally a little bit so that when the head was fixed and put back on it just didn't mate right. I did mention this to the mechanic and he measured out the block to see if it was warped and couldn't find anything wrong (but maybe it wasn't big enough of a warp to pick up with just a ruler).

Anyway, I'm running out of ideas and looking at others.

Has anyone everheard of a high temp sealant/cement I could use where I don't care too much about getting the head off again?

[cantalibre]

There is a blue compound that you can use (can't remember what it's called!) which will show how well the joint is mating. I think you spread this on both surfaces, replace the head (w/o gasket) and tighten loosely. Then remove and check the blue compound is indented equally all over. As I say, vague, but I recall using this on m/cycle joints to check mating surfaces are flat.

[tHa kNiGHt FaLL]

how can a mechanic check a block or head for leaks? with his eyes?

you usually take it to a machine shop and they clean it thoroughly and do all kinds of pressure tests. you said you had it machined... you shoulda had it pressure tested aswell.

8 outta 10 cracks you won't even be able to see it because the head isn't under compression so the cast/aluminum doesn't expand enough to see it.

with that many miles and it only burns on startup... i wouldn't have even fucked with it. cause that many miles that head and that block a formed to each other...

[dwebb99]

Alittle blue smoke on start-up on a 156k engine.... Whats the big deal here? Quit worrying. It's not like you have no compression and burning tons of oil. I say just drive and enjoy the car and get on with your life.

[jtl]

Trying to get on with my life is the whole point and it won't get very far with an engine burning coolant (which is the issue as I can easily live with a little blue smoke)