head gasket replacement

[greg lousy]

Today I started up my 81 pick up after replacing the head gasket. It seems the gasket didn't seal as I had pressurized coolant (very pressurized) - the same thing as when the head gasket blew initially.

I replaced the head with a remanufactured one. The engine has the 11mm headbolts, which is bothering me more and more the more time I spend on this forum.
Anyhow, I cleaned the top of the block thoroughly when I was in there and noticed no cracks, but now I'm wondering if this could be the case.

Does the block typically crack into a coolant line? or is it more likely I just botched the gasket replacement?

I cleaned and reused the original bolts (I know, probably shouldn't have). I'm positive I got the correctly notched gasket and didn't do anything obviously messed up like put it on upside down. Per Bently, i did not use any gasket sealant. I torqued the bolts in the proper sequence, except for the final torqueing with the engine hot - (because of the geyser situation)


Any tips for inspecting the block once I get back in there? (other than the warpage check)
should I compression test while its still together?

Basically, I'm trying to figure out if this is worth another head gasket, bolts (or studs), labor and what not.

Also, it was humid when I replaced the gasket, could this have messed me up?

sorry, this is a lot, appreciate the help

[CarlosA]

You should check the top of the block for flatness, using a machinists straight edge - something ground to .001" or better (.0001").

However I doubt even if the block were badly warped you would instantly have a leak into the cooling system, must be a crack or those bolts just didnt snug down at all or maybe bottomed out since they are stretched.

The bolts are _designed_ to stretch that is why they are not reusable. If you plan on keeping your car for a while or owning other diesels a set of head studs is a sound investment and all of us like them. It's something you could use for a lifetime of diesels...

[EcoTX]

The 11mm head bolts (Hex head) are NON stretch type bolts and can be re-used.

The 12mm XZN (triple square) head bolts used on the later motors are stretch type and can't be re-used.

Head studs are definitely a good option for the 11mm ones however...

[82vdub]

I would run a compression check before pulling it apart. It will tell a couple things.

- it will indicate overall condition of the engine, since this seems to be a new engine to you and you don't have much history with it.
- it will give an indication of what cylinders are losing compression, so if nothing's blatently obvious as to where the leak is, you can look and look closer at the cylinders that have the low compression.

The 11mm motors that have head bolt/block crack problems are typically on the outer corners of the block, those 4 bolt areas are weak. It easily can crack into a coolant jacket, and probably likely does a majority of the time. I would run a compression check, and at least pull the head back off to see what you can find. If the block is good and you identify where the problem is, maybe it's reusable? Only taking it apart will give you answers.

Why would humidity on redoing a head gasket be an issue other then for the discomfort of physical labor on a humid day?

[greg lousy]

I was worried about moisture on the mating surfaces - could be just me.

i just ordered a compression tester. I figure I'll suck it up and try to get to the bottom of this. Also a compression tester may come in handy if I get to the point of buying a used engine.


here's the funny part

- this is my only vehicle

[Diesel Dean]

I would use head studs when you put the new headgasket back on. I just put studs on my 11mm block, you can run the studs to the bottom of the bolt hole and get a much better clamping force with out cracking the block. I am running a k14 turbo so this will be a good test to see how the studs hold up. I use copper spray gasket sealer every time I install a new head gasket. Spray it on the block,head and both side of the head gasket. Just a light dusting of spray just to get it tackey. I have put about ten engines together with no blown head gaskets. Works for me....

[82vdub]

I also vouch for the use of studs in the 11mm motors. Too many horror stories here. I redid the head gasket in ole 82 and discovered that's it's on of the dreaded 11mm 1.6L motors. It was going to get studs as a 12mm motor, and for sure got them since it's the 11mm motor. The retorque was missing that nasty "the bolt is about to break" cracking noise when I did the retorque. I'd highly recommend them, in either 11 or 12mm block configuration.

[greg lousy]

I've read the stuff here about studs and even checked them out online. makes sense.
If I take a look at things and become confident that the block is good, I may make that move.

[greg lousy]

Well this is kind of interesting. I ran my engine to get it warmed up for the compression test, but this ended up being unnecessary as the problem area was obvious. I noticed a small amount of exhaust blowing out of side of the engine, right at the head gasket, underneath the side water flange.
I took the head off to check things out. I have yet to clean off and carefully check the block, but I think I may have found the problem - in my newly remanufactured head. There is a thin ridge of metal at the edge of the mating surface. The location of this ridge corresponds exactly to the exhaust leak, and the related damage to the new head gasket. There are some ridges elsewhere on the outer edge of the mating surface, but this was the most pronounced - its not much but its there - enough to catch your fingernail if you run it off the mating surface. Could this be the problem?

I could be wrong, but it here's what it looks like. When the mating surface was ground some excess metal flayed off the edges. This excess was then ground away perpendicular to the mating surface, forcing some of it back onto the mating surface, creating this ridge.

Also, now that I'm really looking at things, I see that the head gasket has round holes that line up with triangular coolant passages. Also, there's three holes in the head that do not have corresponding holes. Is this right? (its a Victor Reinz gasket)

as always - thanks

[Fatmobile]

Yeah, it's common for some of the coolant holes to be blocked by the gasket,
it's supposed to direct coolant flow.

The 1.9 also has coolant holes where the corners of the cylinders meet.
Sometimes I add these holes to the 1.6 head, block and gasket so air bubbles and steam can't build up in the corners under the surface of the block.