possible head gasket leak or?

[9365turbo]

I have a 2002 duramax. I have been having trouble with coolant burping out. I thought I had it cured. The coolant was low so it had some air in the system. I purged the system and keep a eye on the coolant tank. My drove the truck and he only went abot 10 miles. He said it wasnt warmed up yet. When he shut it off in the driveway it burped coolant out. So I would like to know how do I find out if I have a bad head gasket or a injector seal going bad?
I had to replace th water pump a year ago. I shouldnt have to baby the truck at least I hope not. The truck puts out no smoke and runs just fine. I real tired of have this problem.

[dr.olds]

Jeff, sorry to her about your problem. been there done that! heres a senerio, have you ever had injectors replaced at any time? what can happen is when the dealer replaces inj. they might get a little rough doing so, in which case it can loosen the seal around the inj. cup, if the cup comes out with the inj. they will reseal it, if it doesnt they dont mess with it. (talking from experience) the cup (or sleave) which ever term you prefer, is sealed with the equvelant to red loctite! do you run any type of performance upgrades on your LB7? this could be another factor. its one of those things roll the dice and take your chances! mine turned out to be a blown head gasket after I resealed the cups! its not an easy task no matter what. the process is not realy that difficult, just time consuming! would not trust a dealer! if this is some thing you are going to do your self, feel free to contact me any time. I even have part #s for every thing you will need, keep in mind there is nothing cheap about a Durmax! Just spent $900 on mine for the same problem, I took a few extra steps to ensure it never happens again!!!!!!!!!!!!!!!!! It can be done a little cheaper!:cool: EDDIE

[TomJ01]

I have a 2001 Duramax. I had coolant system problems, coolant burping out of surge tank intermittantly. I did coolant analysis thru a big truck shop and the report was clean, no exhaust gasses or foreign materials in my coolant system. I fought this issue for 2 to 3 years, as it would happen only once in a while and I had no performance issues, as I tow an 11000 lb. trailer. GM mechanics ruled out head gaskets.
GM shops seem to have trouble diagnosing this problem. Long story short, I did everything they recommended, including replacing thermostats, injector sleeves, etc., but the last thing was to replace head gaskets. Get a GOOD mechanic on this job. My truck was in the GM shop for the better part of 3 months and I have had to have a substantial amount of the work redone as many of the new seals, hoses, cross over pipe, etc., were still leaking coolant. My work over the entire period cost me about $7,000, as I was slightly out of warranty time, but well under warranty miles. GM finally agreed to pick up 50% of parts and labor on the head gasket change. Make sure, if its head gaskets, that you get the new gaskets. Good luck, if its head gaskets, you should be able to detect bubbles coming into the surge tank, especially on cold starts, that is when my surge tank puked the worst.

[More Power]

I haven't heard of a good way to determine whether the cooling system overpressure problem might be related to either the LB7 injector cup sealing or head gaskets.

Here's what I would do....

If the injectors had been replaced sometime in the 12 months prior to your first recognition of a cooling system overpressure problem, I'd lean toward an injector cup seal leak as the cause - unless you've been hot-rodding the truck.

If a connection can't be made between injector replacement and a cooling system overpressure issue, I'd suspect a head gasket.

If you're doing a head gasket replacement, I'd have the injector cups re-sealed at the same time.

There seems to be a connection between water pump leaks and cooling system overpressure. If the water pump hasn't been replaced, at the time the head gaskets/cup seals are being replaced, it might be a good idea to replace the WP at the same time. Ordinarily, these water pumps should last for nearly the life of the engine. Someone reporting a leaking WP seal causes me to think cooling system overpressure... And... I'd replace the coolant surge tank pressure cap when doing any of this. The cap is supposed to vent at 15-psi, which might not be happening.

Jim

[Kennedy]

Good advice from MP. Odds are it's a head gasket issue. If in doubt pull up the cups and reseal as well.

The water pump issue I believe to be just an all around issue. They just don't seem to live that long in some cases. Mine was done on my 2002 a while back and it did not pressurize.

[dr.olds]

hey Jeff, been a while since we spoke on the phone, have you got started on this project yet? let me know how it goes! thers a lot of good advice on this page! these people seem to know their s#@t!:cool:

[9365turbo]

Sold my camper today. So I need to egt it done before I buy a bigger one. What do I need to complete the kob? Parts,tools, sealants. Thanks.