04.5 with fresh lmm/lbz(checked n decked) heads, gaskets n studs. Somehow I'm burning coolant. I have a hard time believing that I have a gasket issue as I have no pressure in the cooling system. I've pressure checked it hot and cold and I lose 2 lbs in about 20 min. This has been going on for 2 weeks and I didn't notice any white smoke until today. The truck was hot and sat for 45 min and upon start up a nice white cloud from the tailpipe. Has anyone had a turbo leak coolant internally?
Coolant loss, Turbo?
- Thread starter jwilliams198
- Start date
Stock heads, or ported? I've had really bad luck with ported heads leaking coolant into the intake and exhaust.
What I've done to find the leak is pressurize the cooling system for long enough you lose half a gallon. Pull all the glow plugs, and slowly rotate the motor over by hand. See if any comes out the glow plug holes. If so, you have a cracked intake runner. If not, pull your EGT probe and fire the motor. If coolant/smoke comes out, that's the side with the problem.
Since you have a water cooled turbo, that complicates things. I'd bypass the turbo for the pressure test. If it stops leaking, the turbo was your problem. If it keeps leaking, the problem is elsewhere.
Finally, a test that finds intake runner leaks quickly is to do a boost leak rest while the coolant tester is hooked up. Put 10-20 PSI of air in the intake, and if coolant pressure goes up off 0 PSI, you have a cracked intake runner.
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What I've done to find the leak is pressurize the cooling system for long enough you lose half a gallon. Pull all the glow plugs, and slowly rotate the motor over by hand. See if any comes out the glow plug holes. If so, you have a cracked intake runner. If not, pull your EGT probe and fire the motor. If coolant/smoke comes out, that's the side with the problem.
Since you have a water cooled turbo, that complicates things. I'd bypass the turbo for the pressure test. If it stops leaking, the turbo was your problem. If it keeps leaking, the problem is elsewhere.
Finally, a test that finds intake runner leaks quickly is to do a boost leak rest while the coolant tester is hooked up. Put 10-20 PSI of air in the intake, and if coolant pressure goes up off 0 PSI, you have a cracked intake runner.
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Coolant enters the turbo and fills the cavity around the cartridge and there are no wear items for the coolant to leak passed. Now that doesn't mean the cartridge casting can't fail and allow water into the rotating assembly but if that were the cast you'd have milky oil; if you're going through water quickly.
Yellowchevy
Yellowchevy
So it's leaking out of the # 4 exhaust port. Seems to be coming from the roof of the port. These are stock heads so I guess it's just a bad one. I threw some gm stop leak tablets in the coolant and it's helped a lot. I'll pull the head when I get laid off this fall. I'm just disappointed that the local "good" head guy didn't find it in his pressure test..
Oh don't even get me started on people not finding cracked heads... I've put 3 sets of heads on my truck in 14,000 miles thanks to coolant leaks, so I feel your pain.
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IIRC correctly GM had a TSB out years ago about using stop-leak in a diesel engine, not a good idea.
X2, Stop leak is nasty stuff, it will plug the small passages in you're radiator, egr cooler and other small orifices. I wouldn't recommend continuing to run it like that, you will develop hot spots in your cooling system that will be hard to remove and possible cost you more in repairs in the long run.
No egr cooler left on this truck. I was talking to a gm tech about this problem and he was telling me about a tsb that gm had about using this stuff in Cadillac norstar engines to fix coolant loss. I'm sure those radiators have the same size or smaller passages in the system.
The EGR is not the problem, this TSB dates back to shortly after the Dmax was designed, the problem is it's a diesel engine not a gasser that has different cooling characteristics than a Northstar engine..
The stock castings are usually good, but I'm currently running the Wagler (Brodix) castings with no porting. Only been on a little while, I'll see how they hold up.
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