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the sweet smell of antifreeze spewing from the motor

OK, long story short, my 3 month old head gasket is blown. I've no choice but to put another one on, but I would like to brainstorm what could possibly be the problem in advance of pulling the head and seeing the evidence for myself.

The gasket had about 1200 miles on it. No problems with it until it just went all of the sudden.

How it went: I was driving to work on the first extremely cold morning we had. Went out to get food first. I was doing about 35. The motor gradually began to run erratically. I dropped into neutral and gave it some gas. Noticed a billow of smoke out the tail. Wonderful, I'm thinking - lost a ring. A little bit later I smelled antifreeze and there were wisps of smoke from under the hood. Then I knew it was the gasket. Drove to work and parked it. Looked under the hood and saw antifreeze and oil leaking out from the gasket onto the block and tranny case. After after work I drove it the few miles home (damn the torpedoes!). When I got home, I checked the oil. It was a mess as could be expected.

The last time I got gas, I had checked my oil including under the cap, and it was clean. I now have 47 miles on the odometer. So this was quite a sudden breakdown. It may have been gradually weakening and then finally gave out altogether today.

I ordered a new Felpro gasket which I will have on Friday. Hoping to get the gasket done in 1 day this time now that I know what I'm doing. But I would really like this to be the last time.

Here is what I did last time:

- Used an exchange rebuilt aluminum cylinder head

- Cleaned the old gasket off the cast iron block with a metal scraper (some have said a rotary wire brush is a better idea)

- Checked both the head and block for straightness as best as I could

- Cleaned up the head bolt threads until I could finger screw the bolts in

- Cleaned all oil/antifreeze/machine lube off the block and head with MEK

- Placed the dry Felpro gasket, fresh out of the sealed plastic bag, onto the block aligned with the two dowels, correct side up

- Placed the head straight down onto the block with the aid of a helper

- Tightened the new head bolts to exactly the correct torque, using a quivering wand Craftsman wrench, in 3 stages using the proper torquing sequence.

What I screwed up:

- Initially I did not oil the head bolts and tightened them down dry. I realized my mistake while reassmbling the motor and 1/2 hour later, loosened them in the correct sequence, removed them one by one, oiled them, and then retightened them to the correct torque as before. I am not certain if this affected the gasket in any way.

- My 3 stage torque values were arbitrary - 1/3 final torque, then 2/3 final torque, then final torque. I do not know if this is correct. The factory manual only lists a single torque value.

What I did not do:

- I did not attempt to resurface the deck in any way besides removing the old gasket

- I did not check closely for burrs around water or oil passages and file them down

- I did not use any kind of sealer on the gasket - it was completely dry and the surfaces clean

- I did not retorque the bolts after 500 miles since no manual suggested that I do so

Complicating factors:

- Several weeks after replacing the gasket, I had a coolant leak. This turned out to be a broken radiator hose clamp. I replaced all the clamps at this point.

- Several weeks after that, a rock knocked a hole in my radiator. I did not notice it for several weeks; I only noticed a coolant loss when I checked. Then I realized I could squeeze a hose and a stream of water would squirt from the radiator. I had the radiator repaired. This was several weeks before I lost the gasket.

Even with the above coolant issues, I have never noticed the temp gauge above the middle where it has always been. So I do not believe I have overheated the head, but the rebuilder said they put an overheat tab on it that melts if it gets too hot, so I'll be looking for that when I get a chance. If it did not overheat, I am inclined to believe that the problem is not with the head.

I am wondering if I need to do a better job of preparing the deck. What is the best way that can be done at home with hand tools? At some point, it was suggested to me to use 80 grit sandpaper on the deck to give it texture, but the head rebuilder said NOT to sand the deck at all and especially not with a coarse grit, so I declined to do so.

The motor is Isuzu 4XE1 4-cyl SOHC. Not a motor known for gasket problems. I'm tempted to say that the cold had something to do with the failure, but that would be implying causation from correlation. And none of us are willing to do that. Right?

Does anyone have any other suggestions to improve my chances of the repair lasting? They say the definition of insanity is doing the same thing over and over again and expecting different results, so I'd like to at least TRY to improve my procedure somehow this time. (Or I could just bask in my status as a looney-bin destinee.)

This event came one day after the hard drive in my main workstation crashed (a total loss), so bear with me if I haven't quite thought things through thoroughly. Life has not been pleasant lately, to make an understatement. There are many advantages to the life of a self-sufficient university student, but having the luxury to throw old things away and buy new ones is not one of them. Believe me, right now there is nothing I would like to do more than set my car ablaze and roll the smoking carcass off a towering cliff, preferably to come to rest upon a bed of sharp spikes of some sort. But I've got to get 2 more years from it somehow (a reasonable goal given the amount of new and rebuilt parts that are on it), and sadly enough my time right now is less valuable than nearly any amount of money. So in the end a time sink like a gasketing issue is not a problem for me... I've just got to keep my sanity somehow while I fight it.

Maybe I should try "Elmer's Glue" as a head gasket, after all just about anything could last 3 months right? And a bottle of glue is cheaper than a $40 gasket...

I'll post again once I've pulled the head off. Probably be Friday.

Thanks.

Reply to
Ryan Underwood
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Having read your post, I did not pick up on anything you did that was really wrong.

-The head and block needs to be straight, and you checked that.

-The head bolts need not be oiled before torqueing, but should be clean. If you oil them, you might get them a little tighter than you would have done with them dry, since the friction component in the threads is much lower BUT that is usually in the range of 15%-20%.

N.B.! Some headbolts cannot be reused. They were tightened not just to a torque, but to a mechanical yield, and must be replaced. Don't know about yours.

- Head gasket sealer is not generally needed, nor recommended.

- Increasing the torque on the headbolts in increments is fine. No problem there. Did you follow the tightening sequence specified for this engine?

You probably should have come back after a couple hundred miles or so and retorqued. Be sure to use the tightening sequence here too.

Let us know what you find when you open her up.

Reply to
<HLS

First guess is the reman head wasn't flat. Next guess is the gasket was damaged when the head was tightened, loosened and retightened.

Reply to
John S.

My guess is that you compressed the head gasket enough on the first go-round that, as Wallace would say to Gromit, "the bounce was gone from its bungee" the second time around.

It doesn't sound like this engine uses "torque to yield" head bolts either, since you mention a final torque value instead of a final torque value PLUS a half turn (or full turn, or whatever the manual states). But if you missed that and it does use TTY bolts, get new ones and follow the TTY procedure as this is what provides the correct clamping force in those designs. Re-read the manual (hopefully it is a FACTORY manual and not a Haynes or Chilton or other) and make sure it doesn't specify a torque plus turns.

Reply to
Steve

If you torque to the same spec, there shouldn't be any difference except for the lubrication of the threads and that would just increase the torque to the correct spec.

Reply to
Bruce Chang

We've been down this road before, Bruce. There actually will be a difference in clamping force, even if you torque to exactly the same torque figures, for dry versus lubricated bolts. I found documentation that to get the same clamping forces (bolt elongation) you would normally need to decrease the torque to a lubricated bolt by 15-20%. If you don't the tensile forces on the bolt will be greater with the lubed threads. Does it make any difference? Maybe. And maybe not.

Extra clamping force may help it seal, but if you get into the range where the elasticity limit is exceeded the headbolt could stretch and either break or remain deformed. Once deformed, it will not regain its strength.

Usually you can get away with it, but not always.

Reply to
<HLS

Extra clamping force is moot if the first go-round compressed the head gasket, though. Its "used" at that point and not good for anything.

Reply to
Steve

Fully agree, Steve. I felt that Bruce was probably oversimplifying the effect of lubricating the threads, and wanted to say that the effect is real, and can get you into trouble on rare occasions.

Reply to
<HLS

I'm agreeing with you. If that is what is called for (I know the SBC requires dry threads) then the first time he torqued it, the torque spec was

*below* the specification, using your data, 15-20% lower than what was needed. With the lubed bolt, he would have 15-20% more torque applied and further compress the head gasket. This is all under the assumption that this headbold elasticity limit was not exceeded because the first time he torqued it was under spec because the installation was not to spec (dry threads as opposed to lubed threads).

On the other hand, if the spec is with dry threads then he's exceeded the torque spec and possibly the torque limit of the head bolt and, like you've already said, who's to say whether it'll hold or not.

-Bruce

Reply to
Bruce Chang

You can only use a head gasket once. You used that one twice.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Ryan Underwood wrote:

Reply to
Mike Romain

How exactly did you do that?

In reading through the posts most people say the gasket was toasted when you torqued, loosened, then retorqued. I don't believe this was the problem, however. You said you loosened the bolts one-by-one, that would make it impossible for the gasket to have slipped or moved during the loosening. This is, in fact, the exact way you used to retorque the old asbestos head gaskets - you let the engine cool down to stone cold then loosened and retorqued the bolts. The fact is that with oil on the threads and the gasket already compressed a bit once, you would have got even further compression when you retorqued.

The only exception is if these were torque-to-yield bolts, but you indicated they wern't.

I think either your block or your head is warped. You need to go to a machine shop supply store and get a straightedge designed to be used to test for warping. I understand that precision tools are fricking expensive but this is not an area that you skimp on. Also, you made a mistake doing the exchange rebuild, unless your head was totally shot, you should have had a machine shop redo yours. Exchanges are fine for things like axles or starters or alternators, but your taking a risk with heads. Rebuild houses have to toss probably around 50% of what comes back in exchange, and they make it up by purchasing cores from "core companies" who are basically people who spend all day calling and running around to wrecking yards looking for parts, and what they get has been sitting around often for months, and corrosion can start pitting precision surfaces pretty quickly. The head you have might have been milled a bit to clean it up and they didn't do a good job of it.

I myself have done head gaskets a number of times and they haven't leaked, and I didn't check them for straightness. That was when I was a lot younger and poorer. And I think the majority of DIYers also get away with not checking for straightness either. Most of the time if you catch the overheat early the block or head does not warp, so your OK. But this is mostly luck.

Ted

Reply to
Ted Mittelstaedt

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