Sounds like a blown head gasket, which seems unusual for a 2014 but not impossible.

 

Not sure what’s going on but I have to add about 8oz of coolant every 60 days or so. This morning the low coolant warning light was on so I went to add more. Once I opened the cap to fill its like there was a bunch of built up pressure and the coolant in the reservoir started spraying everywhere so I closed the cap and now the level of coolant is completely full without adding any. What’s up with that??





Because this has been going on for about a year now I took the truck to the shop a couple months ago and they pressure tested the coolant system and said they could not find any leaks. Any thoughts on what is going on?



2014 Chevy duramax with zero mods.

If the truck just ran you’re going to have built up pressure in the system no matter what...but ya could be a headgasket failure but usually those drink more coolant more often. If it worsens then i would assume headgasket


-head studs and gaskets
-66mm (stupid loud)
-5” straight pipe axle dumped
-shimmed
-full s&b intake and mouthpiece
-dans diesel 800 HP built trans with biller stator
-dans built trans tunes
-glowshift EGT, boost(not working because i broke it), fuel pressure(have not found a sender to work for it help please), edge cts2
-PPE sleeves
-fuel lab 100 gph lift pump

 

Thanks for the replies. The truck ran maybe 5 miles and I let it cool for 20 mins before I unscrewed the cap. Once the air pressure was released the fluid level went back to the top and I didn’t have to add anything else. Today anyways.

Not sure if it makes a difference trying to figure out the culprit for the loss of coolant but I did get an oil analysis done about 6 months ago and there was no coolant in the oil.

Without tearing the engine apart how would I know if the head gasket is the issue? Zero loss of power and absolutely nothing else wrong with the truck. No CEL either

 

Thanks for the replies. The truck ran maybe 5 miles and I let it cool for 20 mins before I unscrewed the cap. Once the air pressure was released the fluid level went back to the top and I didn’t have to add anything else. Today anyways.



Not sure if it makes a difference trying to figure out the culprit for the loss of coolant but I did get an oil analysis done about 6 months ago and there was no coolant in the oil.



Without tearing the engine apart how would I know if the head gasket is the issue? Zero loss of power and absolutely nothing else wrong with the truck. No CEL either

Thought maybe you could loosen the oil cap while the truck is running to check for blow by. If it stays in place apparently it indicates the gaskets are fine but if it pops off and hovers around it indicates they could be toast


-head studs and gaskets
-66mm (stupid loud)
-5” straight pipe axle dumped
-shimmed
-full s&b intake and mouthpiece
-dans diesel 800 HP built trans with biller stator
-dans built trans tunes
-glowshift EGT, boost(not working because i broke it), fuel pressure(have not found a sender to work for it help please), edge cts2
-PPE sleeves
-fuel lab 100 gph lift pump

 

Replace your surge tank cap 1st (it's cheap).
And wrap a paper towel around your surge tank overflow tube end.
Looking for residue on it to verify that's where the coolant is exiting the system, and not leaking elsewhere.

8oz in two months....kind of normal on most with some miles on 'em.

 

Just had both thermostats replaced about 4-5 months ago. Have about 135k miles on the truck right now.

I try and YouTube the bleeder screw thing and see it that helps. In the last 24 hours the coolant levels have been good

 

Ok where is the bleeder? I cannot find anything for a 2014. Every video I can find are for old trucks and I don’t see the screw in the same location??

 

I don't know if the 2014 thermostat housing is different than an LB7, but here it is on an older Duramax:

 

It's different. I don't think it has one.
I question opening that up anyway, as it's at a lower point in the system than the full coolant line level.

 

Do you guys think there is any problem filling up one of those disposable water bottles with extra coolant? Not sure if the chemicals would eat the cheap water bottles

 

I don't think so, but put some in the bottle, set it inside a 5 gallon bucket and see what happens if you are worried about it.

 

That’s what I was wondering. Guess I will just haul around a gallon jug of premix in my tool box

 

I know I'm late to the party, but have you thought about putting UV dye in your coolant? I had a similar issue on mine that I couldnt locate. Finally found that my weep holes were leaking on the pump.

Just a thought...

 

Well took the truck to the shop today because I cannot figure it out. Went through almost a gallon of coolant in the last 2 weeks and I don’t see any leaks...?????

 

Well took the truck to the shop today because I cannot figure it out. Went through almost a gallon of coolant in the last 2 weeks and I don’t see any leaks...?????

oldone

.....wrap a paper towel around your surge tank overflow tube end.
Looking for residue on it to verify that's where the coolant is exiting the system, and not leaking elsewhere.

'dunno;

 

Well they didn’t find anything but they put some sort of “pellets” in the coolant system that are supposed to pull any hair line type holes.... we shall see