LBZ: Help with head gasket or coolant problem

[ToyhaulerTom]

I'm new to on-line help, but have really picked up a lot of info from you all. I've worked on gas engines most of my life, but a lot of parts on a diesel are new to me.
So, here's my story: While towing cross country, I started using coolant. System stayed pressurized, but was turning black with soot. I assumed I had blown a head gasket. Got it home to a truck mechanic who said it was my EGR cooler and he replaced it. Things got somewhat better, no more soot, but the system would belch out coolant even after 24 hrs of cooling down. I haven't been able to stablize the coolant level and I've been told by a GM mechanic that if the system stays pressurized overnight, he's a 100% sure its a HG. Another odd deal is once I've released coolant pressure and go for a drive, the temp warms to 175 in 2 miles then down to 160 in another mile, then after 3 or 4 miles go to 205, then stabilize at about 185?? The heater air reflects the same fluctuations.
I also have added a secondary bottle to the overflow tank and bubbles are observed in the fluid. It's a new cap and tank. Gaskets and parts are on order for a head removal adventure.
Any ideas?

 

[onebaddmaxxx]

Stay on track for head gaskets. The coolant is going up and down because its getting air pockets in from the cylinders. Im actually pulling mine apart tomorrow for head gasket issues. I am blowing coolant out of the overflow, and my heat is in and out. If i grandpa the truck it will never get warm enough to make heat.

 

[ToyhaulerTom]

Thanks Onebaddmaxx,
Do you think it's worth another $50 by investing in one of those blue chemical tests that sample for exhaust gases in the coolant? I'm considering it, although my mind is pretty well made up to tear into it.

 

[whitetrash21]

Assuming you have an 04.5 and newer truck, head gaskets are most likely the problem. The lb7 could have similar symptoms but also used removal cups which can lift and pressurize cooling system. The soot you're seeing in the reservoir most likely indicates a head gasket issue.

Make sure you get the heads pressure checked and surfaced before remounting though..... Rule out any issues with a cracked head.

 

[Robby05]

Might as well replace the water pump, t-stats & hoses while your balls deep in there

 

[ToyhaulerTom]

Thanks Gearhead,
I've got a new water pump coming, but not sure what the removal cups the you refer to are. How do they play in this picture? And, while exposing my lack of knowledge, I've seen threads where guys are talking about fuel injection nozzles cups coming loose. Is this what I need to look for? What should I look at?

 

[whitetrash21]

If you truck is an lb7, you'll want to pop the cups out of the head and reseal them. Too many stories of people doing injectors or head gaskets, putting everything back together, only to have a cup lift after its running.

If you have an lly or newer motor code, you don't have to worry about cups ..... They don't have any.

 

[ToyhaulerTom]

Is a 2006 LBZ immune to this?

 

[PACougar]

Is a 2006 LBZ immune to this?

Yes, you don't have injector cups. You do however have a blown head gasket.

 

[whitetrash21]

Yes, you don't have injector cups. You do however have a blown head gasket.

What he said^^^^

 

[NJ_LLY]

Remove your EGR for God sakes! I had about 1/8" of soot buildup on my y bridge, Intake runners, and intake side of my heads last week when it came apart. It truly is amazing how much shit the EGR and the pcv reintroduce into the motor.

 

[ToyhaulerTom]

NJ LLY,
I would love to dump the EGR Cooler, but I'm concerned about throwing codes, reprogramming, and the wonderful peoples republic of California. Did you have any problems in this area?
I may go to the Sinister Upgraded EGR Cooler. I still have options I guess.

 

[andy-stevenson]

Looks like it's time for me to do my headgaskets as well...

 

[ToyhaulerTom]

Hey Andy Stevenson,
What's the issues with your truck?

 

[whitetrash21]

NJ LLY,
I would love to dump the EGR Cooler, but I'm concerned about throwing codes, reprogramming, and the wonderful peoples republic of California. Did you have any problems in this area?
I may go to the Sinister Upgraded EGR Cooler. I still have options I guess.

Hot tank all your intake parts when you tear down the top end. That'll get all the carbon and soot build up out of the motor. Then install a blocker plate on the egr cooler....its subtle enough it most likely won't be seen when you need to smog the truck. Same for a pcv re route....however, done right, pcv is easy to hook up for a smog check visual inspection.

By doing those two things, you'll get rid of all the soot and oil vapor being re introduced into your motor. No more carbon buildup

 

[andy-stevenson]

Hey Andy Stevenson,
What's the issues with your truck?

Losing coolant daily. Hard upper rad hose after the truck sitting for 12+hrs, coolant wants to explode out of degas tank after sitting for 12+hrs. Heater blows warm air then cooler air. Coolant temp goes up, then down, then up

 

[ToyhaulerTom]

Wes,
Thanks for the tips and I will probably put them to use. I hate the stupid EGR cooler idea, and to eliminate it from the equation can't be bad.

 

[ToyhaulerTom]

Andy,
Sounds just like mine, but when it is running, it runs normal. I'm digging into it at the end of next week. Keep us posted on your progress.
Tom

 

[onebaddmaxxx]

Pull the thermostats out, and start the truck with them out and the housing off. Fill the housing up with water and let it sit there and run. look for bubbles coming up. whichever side they come up from is what head gasket is blown

 

[ToyhaulerTom]

You guys were right!

I removed the passenger side cylinder head yesterday (driver's side next) and as all you guys predicted, BLOWN. It looked just like the ones I've seen pictured, but now I'd like some more input.
When I pulled the injectors, the stem was nice and clean on 7, and the other had a brown stain near the tip. The O-ring on that one had been damaged on factory installation and the cylinder it feeds, is also the one where the gasket failed. The head bolt in this location also shows a lot of rust for an issue just presenting itself. Could the bad O-ring have lead to the cylinder gasket problem?

I'm figuring out now how to post pix.
Tom