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06 LBZ getting smokey and laggy

Thanks for the quick responses.

I replaced the water pump at 150k its been 130k since so that's very possible.

I changed the fan clutch, coolant cap, tstats, and probe all at 240k. I know they can all fail but when my truck hit 230k my temps do try to drop until it unlocks at 200. Any way to test the fan clutch? Its pretty easy to spin.
 
#1 glow plug and occasional egr fault.

I am back on stock tuning, the local guys egr delete tune had some funky fue/timing maps that were causing the smoke. I ordered a dsp5 from Idaho Rob with insite/expandable egt/back up cam. Not installed yet, I want to figure out the temp first.
 
Excellent.
Good idea to get the temps figured out first. I would check to be sure that the water pump is putting out what it should be.

Do you notice a big difference going back to the stock tune?
 
Wow. More mpg's with the stock OEM tune. Go figure.

Not sure how to do it exactly, but there must be a pressure gauge to check watet pump pressure.
 
I always have a coolant leak when my pumps quit. It could very well be the pump, it cools off if I manually down shift for more rpms
 
When the OEM pump quit, what kind did you replace it with? AC Delco? Or another brand? Just curious.
 
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Have you checked the basic yet to see if the upper hose is pressurizing shortly after startup? Is there any oily sheen to your coolant? SOME LBZ trucks had turbo failures in the castings at higher milage that caused boost pressure to go back into the cooling system. But if your puking out coolant it is either getting REALLY hot(at 15PSI it takes in excess of 255 degrees to boil), or you are pushing pressure into the system from a bad head gasket or in some extreme cases the turbo has done this.
 
I've seen 260, that was the day I lost coolant. Hasn't been low since. No bubbles in puke tank, hose is soft, coolant looked brand new. Just running mostly water now.
 
I do 10 minutes or so. Do it cold and hot.

On testing the water pump: impeller pumps do not create pressure. Only flow, so you disconnect the hose and monitor flow volume. I have no clue on what your gmp is. All the pressure is created by restrictions I. The system, (slight) and mostly the heat wanting to boil the coolant/water and the cap resistance to boiling allowing it to build pressure instead of boiling.

When a water pump leaks out the weep hole, that is from the seal being worn out or damage from debris. I have lost the seal in water pumps, and had to plug them to get home from deathvalley. (Couple eggs in the radiator once, silicone another time). A leaking seal is not the only sign of a non working pump. The impellers can simply wear out from cavitation or erosion causing a loss in flow, and the seal in perfect condition.

The last part is RARE, but diesel guys get it where gas guys don't. You can have a coolant system suck air, allowing a pressure differential and start boiling off coolant at a lower temp than your cap is good for. When it boils it slowly dumps the pressure out the cap like it's supposed to, and you'll notice almost no coolant loss. You will overheat temporarily, then it recovers and all is fine until conditions are just right to do it again.
 
With plastic impellers, they impellers have been much of an issue with the LBZ's. I have only heard of a couple of plastic impellers spinning, and most of them were on trucks seeing well north of 4500 RPM's on a regular basis. I have yet to hear of erosion problems with the housings unlike earlier trucks with a cast metal impeller. And DO NOT plug the weep hole in a DURAMAX if the seal goes out. If you do, it will pump the coolant back into the engine.
 
Is the upper hose a good candidate to watch water pump?

I'm not sold that my cheapie pump isnt just spinning. It only seems to cool at 2500-3k. I don't see 4500 often but I tow at 3k alot and down shift from there.
 
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