New guy with a new to me old truck, headgasket r-n-r questions

[JD300]

Good evening everyone. I recently purchased a 2002 Chevy Silverado 2500HD CC/SB 4x4 with a stock Duramax/Allison combo(CAI and lift pump are only mods I see and know of).136,179 miles on the odometer, clean carfax, and solid body and frame considering the area it’s from. This is my first Duramax, but not my first Diesel. My first Diesel was a 2024 RAM 2500 CC/SB Cummins that I traded off after 41 days. Anyways, I want to learn as much as I can. I bought the truck with what the owner was told bad head gaskets. From what I’ve read, I think that’s the case. Building pressure in upper radiator hose and if cap is taken off of tank, tiny air bubbles becomes big air bubbles that burps out. Point me in the direction of a complete kit to do head gaskets and if there is a step by step write up, that would be awesome. I’ve been quoted anywhere from $3,500 to over $10,000 to do the job. The high end figure was given by a guy that was basically suggesting I put everything new from the heads up.
Sorry for the long post.

 

[2004LB7]

Welcome

Could be head gaskets or the injector cups. Difficult to know which one it is.

$10k seems way too high even with rebuilding the heads.

There are a number of people here who has more current numbers.

 

[Chevy1925]

Eh, depends on demographic. Out here it be a 7-10k job at a good shop depending on labor rate and parts markup.

I’d pull glow plugs and pressurize the cooling system. See if pressure quickly falls or not. If it does, crank the engine and see what cylinders coolant comes out of.

Did he have any recent injector work done?

 

[JD300]

Eh, depends on demographic. Out here it be a 7-10k job at a good shop depending on labor rate and parts markup.

I’d pull glow plugs and pressurize the cooling system. See if pressure quickly falls or not. If it does, crank the engine and see what cylinders coolant comes out of.

Did he have any recent injector work done?

The person I bought it off of was a 61 year old woman. She obtained the truck when it had 46,000 miles. She told me within the last 4 years it had glow plugs, possibly thermostats, and tie rods. She had an antique furniture business and used the truck to haul her furniture. She initially told me it started losing coolant and was never overheated and she stopped driving it. Then she said one of her female friends borrowed the truck and it started losing coolant on the way from North Carolina to Maryland. So I don’t know if it was ever overheated.
I appreciate any tips and suggestions. I’ll try pulling the glow plugs and pressurizing the system. I’m a guy who would rather ask dumb questions than do something dumb, so after pulling glow plugs, pressure coolant system to 15psi? Is that correct? Thank you

 

[JD300]

Welcome

Could be head gaskets or the injector cups. Difficult to know which one it is.

$10k seems way too high even with rebuilding the heads.

There are a number of people here who has more current numbers.

Thank you

 

[Chevy1925]

The person I bought it off of was a 61 year old woman. She obtained the truck when it had 46,000 miles. She told me within the last 4 years it had glow plugs, possibly thermostats, and tie rods. She had an antique furniture business and used the truck to haul her furniture. She initially told me it started losing coolant and was never overheated and she stopped driving it. Then she said one of her female friends borrowed the truck and it started losing coolant on the way from North Carolina to Maryland. So I don’t know if it was ever overheated.
I appreciate any tips and suggestions. I’ll try pulling the glow plugs and pressurizing the system. I’m a guy who would rather ask dumb questions than do something dumb, so after pulling glow plugs, pressure coolant system to 15psi? Is that correct? Thank you

Yes sir, 15-16psi and see what the pressure gauge does. Yours is bad enough you ought to see an issue pretty quick (I’d think)

 

[JD300]

Good morning everyone. Sleepless night, so here I am. Pretty certain that the headgaskets needs replaced. Drove the truck about 8 miles yesterday and got it up to temp. Low coolant light came on, no coolant was pushed out, no white smoke, engine tan and sounded fine. It never went above 200°-210°. Upper hose was hard as a rock…I’ll check it today, but I expect it to be. I’ve let the truck idle with the reservoir cap off and little bubbles turns into big air bubbles in the tank.
Can someone please point me in the direction of a quality, complete kit to do the headgaskets? Also, where can I get detailed instructions on how to do it with all of the torque specs? I do have some automotive experience and use to swap engines, transmissions, front and rear axle housings, etc years ago before I had kids. I’m also OCD and like to do things correctly and will follow directions to the letter. I’ve inquired on quotes from several shops, but am leaning towards doing it myself to save money first and foremost but also just so I can learn about my Duramax engine and maybe be able to help someone else out in the future who is in my shoes.
Thank you for any help and info.

 

[TheBac]

1) Moved this to LB7 section.

2) RockAuto for gasket kits, headgaskets and new head bolts. Use Mahle or Victor Reinz for gasket kit and bolts, only GM for headgaskets, grade C.
You could also ask Brad (@Bdsankey) about a kit. Hes a supporting vendor.

3) Get yourself a subscription to AllDataDIY for the steps to replace them and your torque values. Its a ton of steps, and the parts are substantially larger than a gas engine, but its all pretty logical.
You can even look on youtube for videos about specifics if you have to.

4) When you remove the high pressure lines from the injectors, you'll get crap into the injector inlets. Its unavoidable.
Make damn sure to clean the living hell out of those inlets before you re-install the injectors later. Since the truck is 23 years old, you may want to have new rubber fuel lines for around the filter and also new rubber coolant lines, esp the little piece just above the harmonic balancer. Better safe than sorry.

 

[JD300]

1) Moved this to LB7 section.

2) RockAuto for gasket kits, headgaskets and new head bolts. Use Mahle or Victor Reinz for gasket kit and bolts, only GM for headgaskets, grade C.
You could also ask Brad (@Bdsankey) about a kit. Hes a supporting vendor.

3) Get yourself a subscription to AllDataDIY for the steps to replace them and your torque values. Its a ton of steps, and the parts are substantially larger than a gas engine, but its all pretty logical.
You can even look on youtube for videos about specifics if you have to.

4) When you remove the high pressure lines from the injectors, you'll get crap into the injector inlets. Its unavoidable.
Make damn sure to clean the living hell out of those inlets before you re-install the injectors later. Since the truck is 23 years old, you may want to have new rubber fuel lines for around the filter and also new rubber coolant lines, esp the little piece just above the harmonic balancer. Better safe than sorry.

Thank you so much for the info

 

[JD300]

Good morning everyone. Sleepless night, so here I am. Pretty certain that the headgaskets needs replaced. Drove the truck about 8 miles yesterday and got it up to temp. Low coolant light came on, no coolant was pushed out, no white smoke, engine tan and sounded fine. It never went above 200°-210°. Upper hose was hard as a rock…I’ll check it today, but I expect it to be. I’ve let the truck idle with the reservoir cap off and little bubbles turns into big air bubbles in the tank.
Can someone please point me in the direction of a quality, complete kit to do the headgaskets? Also, where can I get detailed instructions on how to do it with all of the torque specs? I do have some automotive experience and use to swap engines, transmissions, front and rear axle housings, etc years ago before I had kids. I’m also OCD and like to do things correctly and will follow directions to the letter. I’ve inquired on quotes from several shops, but am leaning towards doing it myself to save money first and foremost but also just so I can learn about my Duramax engine and maybe be able to help someone else out in the future who is in my shoes.
Thank you for any help and info.

Checked upper hose this morning 12 hours later…it’s like a tennis ball.

 

[TheBac]

Thank you so much for the info

Yeah, been there, done that. Rebuilt my LB7 in my garage by myself back in 2010. It was very satisfying work.

 

[JD300]

Yeah, been there, done that. Rebuilt my LB7 in the garage by myself back in 2010. It was very satisfying work.

What do you recommend I use to clean injector inlets with?

 

[darkness]

What do you recommend I use to clean injector inlets with?

Tap them upside down to clean them out. Don’t use any pressure sprays or air or you can push debris further in.

 

[JD300]

Tap them upside down to clean them out. Don’t use any pressure sprays or air or you can push debris further in.

Thank you for the advice.

 

[Bdsankey]

Mahle HGs are the only thing we use and sell here at my shop. GM golds are proven to be too unreliable for me to use them. As for the remaining gaskets (IE everything else except the actual HGs) I use Mahle/Victor Reinz as my "go to" but I've also had great luck with FelPro when they were the only option in stock.


As others have said, make sure you DO NOT use any pressurized method for cleaning the inlets.

 

[JD300]

Mahle HGs are the only thing we use and sell here at my shop. GM golds are proven to be too unreliable for me to use them. As for the remaining gaskets (IE everything else except the actual HGs) I use Mahle/Victor Reinz as my "go to" but I've also had great luck with FelPro when they were the only option in stock.


As others have said, make sure you DO NOT use any pressurized method for cleaning the inlets.

Thank you for the info. Is there a complete kit I can obtain for simplicity sake? Any other advice is greatly appreciated.

 

[Bdsankey]

Thank you for the info. Is there a complete kit I can obtain for simplicity sake? Any other advice is greatly appreciated.

Yes, I offer an "all in one" kit that has everything you need. I'd be happy to get one headed your way.

 

[mojito5000]

Good choice on truck. I'll never part-ways with my 01'. It might not be the fastest truck, but I haven't encountered a mountain I couldn't pull my travel trailer while maintaining the speed limit.

Head studs would be a worth while investment as well. I did my engine in '20 as my covid project. I ended up pulling the engine from the truck as I couldn't get the drivers side head to clear the firewall. It wasn't too bad to pull the engine after removing the radiator, condenser, IC, and supports. Rebuilding on a stand was a piece of cake.

Also, make sure to use some loctite retaining compound in your injector cups. The cups seem to be a common failure in these engines, and the retaining compound removes the questions. Some guys say you can use regular loctite red, but I figured if I was this deep, I might as well do it the suggested route.

 

[JD300]

Good choice on truck. I'll never part-ways with my 01'. It might not be the fastest truck, but I haven't encountered a mountain I couldn't pull my travel trailer while maintaining the speed limit.

Head studs would be a worth while investment as well. I did my engine in '20 as my covid project. I ended up pulling the engine from the truck as I couldn't get the drivers side head to clear the firewall. It wasn't too bad to pull the engine after removing the radiator, condenser, IC, and supports. Rebuilding on a stand was a piece of cake.

Also, make sure to use some loctite retaining compound in your injector cups. The cups seem to be a common failure in these engines, and the retaining compound removes the questions. Some guys say you can use regular loctite red, but I figured if I was this deep, I might as well do it the suggested route.

Thank you for the reply and the info. I appreciate it.

 

[JD300]

Yes, I offer an "all in one" kit that has everything you need. I'd be happy to get one headed your way.

Is there a link or site to see it? Thank you