head gaskets leaking

[JIMMYV]

truck has 127000 using very little water has any one else had or heard of this problem

[Kennedy]

I've heard of very few issues with coolant loss. Some were head gasket/injector cup seals. Others were water pump. Also, the aluminum tuube that runs fron the heater core to the radiator can be a potential leaker right where the stay bracket is welded to it. Mine weeps ever so slightly at this point.

[flarsen]

Coolant loss issues can be tough to solve. I just traded my 2001 for reasons unrelated to this issue, but the last six months have not been pleasant. My coolant loss was occuring through pressure build-up in the cooling system resulting in coolant being blown out the surge tank through the overflow. Others on this site have had the same problem. GM first replaced the two thermostasts thinking they were sticking. Problem not solved. They then replaced all injector cups and O rings since some of them showed signs of coolant blow by. Problem not solved. They then removed and pressure tested both heads with no leakage found. Reinstalled heads with new head gaskets. Problem not solved. Finally had a regional service guy take a look and he found that the head had been etched around one of the previously faulty injector seals. The etching was microscopic and could be seen only with high magnification. He also said the pressure test was probably pointless since they ran pressure only to about 150 psi. He indicated head pressures run closer to 400 psi. They then replaced the etched head, redid all the cups and O rings. Problem solved. From May 1 though Oct 31, I was without a truck for about 16 weeks at various times. Spent a lot of time writing letters and dealing with various customer service types trying to make me go away with those loyalty discounts on "your next GM vehicle" that they try to peddle. Basically their philosophy is they won't do anything until it looks like it will cost them too much to continue doing nothing. I eventually got from GM what I thought I needed to make me whole for all the time they had the truck and continued to make unsuccessful attempts at repair. I put 75K on it over three years on the road full time with our fifth wheel. I loved the truck, and it could pull, and I have no problem with things breaking now and then, but it became a full time job just fighting the bureacracy and corporate inertia to get the process done. Good Luck. Be TENACIOUS.

[dmaxalliTech]

I have done 4-5 trucks for head gaskets. There has been alot of talk of injector sleeve's leaking as well. I had one truck that was leaking bad enough the head bolt nearest the leak was rusting. Not to the point of eroding away, just surface rust. Normally they come out with an oily feel.

The injector cups when leaking will erode the head where the cup seals to it. Simple RED locktight is all that is used to seal the sleeve to the head at the bottom and two orings seal it at the top. The injector clamp actually hold the injector and cup in place. When that surface becomes pitted, the head must be replaced as its non repairable.

One thing to note on symptoms is that usually head gasket failures are associated with coolant coming out of the overflow tube, temp gauge swings, loss of heat intermittantly from the vents (noticed more so in colder weather).