Former VWDieselParts.com Forum

Hi All,

I just went through a full engine rebuild with my 81 Rabbit pickup and after 10,000 miles I have a leaking head gasket (water seeping out of it). Is there a thread that has everything to do to virtually guarantee that the head gasket will last a LONG time? I'm guessing that they should last a while as VW probably wasn't swamped with head gasket warranty issues.

Here are my engine details:

1: Rebuilt 1.6D (with 12 mm head bolts)
2: I used ARP head studs (torqued as recommended to 90 ft lbs, I believe)
3: Rebuilt injection pump (works great but had to tweak the "smoke screw" to make the car move - NO power at all on delivered setting)
4: Rebuild head. This was an 11mm head that I had the head bolt holes enlarged. Mistake? Should I have just found a 12mm head and had it rebuilt?
5: Timing set to I believe about .95 (for power, rather than economy, I read in different places, I think even on this site)

The engine runs great. The temperature gauge was rock solid in the middle until a few weeks ago (about 10K miles). Then it went up one tick mark just as the head gasket started leaking (I'm guessing hot gasses from the cylinder into the water, heating it up). I drive it fairly hard on the interstate (70 mph) but don't flog it getting up to speed or around town.

I'm assuming that the engine/head rebuild shop checked for a warped head and block as they specialize in VW diesels. I didn't do it.

I'm planning on replacing the head gasket but want this one to last (as, of course, I wanted the current one but with no luck).

Any tips will be greatly appreciated.

Steve

I'd use hylomar gasket sealant on the next.

What rpm at 70mph? (or tranny code and tire size)

I've never used sealant when I've done the head gaskets. Not saying that it shouldnt' be used though.

There's a test kit that you can do to see if you are getting combustion gasses into the coolant. I'd test this first before replacing the head gasket if the water leak isn't excessive. Ole 82 has the typical corner weaping coolant issue and no issues with getting combustion gasses or oil into the coolant. This is a common problem on these engines, although one would expect that after 10k miles it wouldn't leak, but that has happened to me before, but for me the coolant leak isn't enough to worry much yet about it yet, as long as oil isn't getting into the coolant either.

Did you retorque the head studs? I did studs on mine (11mm) when I last did the head gasket and when I checked a year later (That's when my head gasket started to leak), the stud nuts weren't as torqued as I would have expected them to be. I'm going to redo the belt this spring, so it will be interesting to see how tight they are after another 2 years of use on it since it was last checked.

TylerDurden wrote:I'd use hylomar gasket sealant on the next.

What rpm at 70mph? (or tranny code and tire size)

I don't have a tach on the care but it has the 5 speed, 020, FN transmission so I think the engine is not over-reved at 70mph.

I'll look into the gasket sealer. Thanks.

Steve

82vdub wrote:I've never used sealant when I've done the head gaskets. Not saying that it shouldnt' be used though.

There's a test kit that you can do to see if you are getting combustion gasses into the coolant. I'd test this first before replacing the head gasket if the water leak isn't excessive. Ole 82 has the typical corner weaping coolant issue and no issues with getting combustion gasses or oil into the coolant. This is a common problem on these engines, although one would expect that after 10k miles it wouldn't leak, but that has happened to me before, but for me the coolant leak isn't enough to worry much yet about it yet, as long as oil isn't getting into the coolant either.

Did you retorque the head studs? I did studs on mine (11mm) when I last did the head gasket and when I checked a year later (That's when my head gasket started to leak), the stud nuts weren't as torqued as I would have expected them to be. I'm going to redo the belt this spring, so it will be interesting to see how tight they are after another 2 years of use on it since it was last checked.

Great input. Thanks.

I haven't done a real coolant/exhaust gas test. I probably should. I did the "glove test" where I put a very thin rubber glove over the overflow tank opening after letting the car sit overnight. After a few minutes of running the glove didn't inflate that I could tell so I guess there isn't much exhaust going into the cooling system. Maybe a tiny amount. Maybe I should try this after the engine warms up (parts expanded, possibly breaking a good head gasket seal).

I re-torqued the head studs a week or so after getting the engine running about 9 months ago. One or two were pretty far off, it seemed (turned almost 1/2 turn before the wrench clicked). I just checked/re-torqued the head by setting the torque to 94 - maybe a bad thing (over-torquing?) - but within 5% of recommended. All stud nuts went a very small amount, maybe 5 degrees, before the torque wrench click. All were fairly consistent, which I guess is a good sign since they were not when I re-torqued just after getting it running..

I never heard of the corners seeping. That seems to be what I have as this seems to be the two front corners. Although it is interesting that my temperature gauge went up by 1 tick mark at about the time when the seeping started. Maybe a it's coincidence. Maybe the change in weather from warm to bitterly cold?

Fortunately (so far!) there is no oil in the coolant. I've been through that nightmare once. Apparently I bought the car with a rebuilt engine - that had a cracked block (that the VW mechanic who sold the car to me "forgot" to tell me about). Oil was going into the coolant pretty badly. I had to trash that block (an 11mm block, BTW).

So, and I'd really HATE to do this to a completely new/rebuilt system (engine, head, radiator and hoses) if there is no exhaust in the coolant maybe I can "fix" this with radiator sealant? That will be my very last resort if at all. Things simply shouldn't leak where they need an additional additive sealant.

Steve

I've noticed over the years that on Ole 82 when it gets cold and you turn up the temp gauge and start sending coolant through the heater core, that the temp gauge rises a bit. There must be enough of a difference in circulation where this changes the gauge, but I never looked further into it than that.

Quantum-man wrote:Get an original asbestos gasket.
In general: [My personal findings]
Periodically revisiting the head bolts is good policy, retorque those that undo with a torque of 60lbft or less. If bolt doesn't shift at say 70lbft, then leave alone. Retorque to 95lbft those that are 'loose'.

I didn't know that there was such a thing as an asbestos gasket. You mean head gasket, correct, not the other gaskets?

Maybe 25 to 30 years ago? Just about any paper gasket had asbestos in it. Along with brake pads and pipe insulation to name just few of the asbestos products. These gaskets were superior to other gaskets because of the long strands that asbestos has. The limey reuses heat shields so I would doubt that he has asbestos head gaskets. But how dryed out are they.
As far as head gaskets go I think I would look into the 1.9TD AZZ metal gasket or TDI Z1/AHU gasket. These engines have a very similar block to the 1.6 just a longer stroke. The AZZ gasket is reuseable. These engine just about never blow head gaskets, not unless they are over heated or crack the block. I don't know how thick they are or if they will work.

I think the problem with fiber gasket is that they compress quite a bit. Metal gaskets don't need re-torquing. The fiber gasket Achilles heel is over torquing in my opinion. If you crush down too much around the studs it will end up getting pried up in the very center between the two studs. If you're careful with these gaskets there's no problem. The metal gaskets probably need closer specs. Here's one thread on it below.

http://www.vwdiesel.net/forum/index.php?topic=30521.0

Speaking from knowledge of old GM engines (specifically Chevy), they used to use steel shim head gaskets as the block and head were all new and within tolerance to spec where just a thin piece of metal would seal things. The composite gaskets came about because over time blocks and heads warp a little, where something that will absorb a little variation in flatness probably came about after many issues with the shim type gaskets. I've even heard that some new engines (not specifically head gaskets) have such tight machine tolerances that some parts or pieces are assembled without any gasket in them.

I owned a 500 single 1952 Ariel Red Hunter. No gaskets. What a leakier. These machines were put together by Fitters. There's millions of them that live in the UK. They still building the Rolls Royce cars by hand.(maybe vw bought it can remember). Their's an company that builds handmade ball bears over there.

Whats the consensus on copper spray? I like it, but I've only done two of these jobs and my preference could very well be in my head.

I like the copper spray.
Because the oil pressure passageway is so close to the front of the block and sometimes it seeps,.. and extra help might stop it.
I haven't had a problem with any engine I've used it on.