Coolant loss?

blackLTZ

Member
May 6, 2016
154
0
16
South Texas!
I was wondering what could be causing to loose coolant on my lml, I don't have any external leaks so it has to be internal, could the Egr cooler be failing even tho truck is deleated? Parts are still in place, is there any kits to delete the coolers ? Or how do I check them? I have to add about 1/2 gal every 3-4 months, or could this be the excuse to get a new one lol..
 

BLACKMAX1

WAY2EVL
Jul 10, 2013
555
6
18
VA beach
Is their any oil present in your reservoir, or coolant in your oil? either way it could be the head gaskets or oil cooler.
 

Hoffie

New member
Mar 10, 2015
212
1
0
Far East LA - aka Phoenix
Sounds like the heads to me. Mine did the same thing until it finally got so bad that I had to replace one of the cylinder heads. You can check the recovery bottle cap to make sure that it is holding pressure or you can go to a shop and have a water pressure test done - very easy and probably do it for free. Better start saving your money up cause the repair is going to cost between $4 - $8k depending on who does it for you.
 

Hoffie

New member
Mar 10, 2015
212
1
0
Far East LA - aka Phoenix
Whatever you do - Do not add any radiator or engine water stop leak to your engine. I can not stress that enough. Diesels do not like that stuff - unlike gasoline engines. Btw, I never saw water in my oil at any time during my issues.
 

blackLTZ

Member
May 6, 2016
154
0
16
South Texas!
Well I got not coolant on in the oil or oil in the coolant, it does holds pressure, if one of the head or head gasket was failing I will have compression in the cooling system, that's why I was thinking of the egr cooler since there's no more exh flow tru them maybe the coolant just seats on the cooler, ima give it another month or so if still doing the same I'll have to think about a new one.
Thanks guys.
 

blackLTZ

Member
May 6, 2016
154
0
16
South Texas!
The weird thing is that it only gets to a certain level and stays that way on the reservoir and the low coolant light doesn't come on either
 
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AZlml

Member
Jun 5, 2016
278
2
18
32
Goodyear, AZ
Mine does the same but during the summer it would take more to top it off. Now it sits at low but the light doesn't come on. Changing oil tomorrow but no oil in coolant thus far, will check coolant in oil. I still have factory emissions, is it possible if it were burning that you would never see it out the exhaust?
 

WVRigrat05

Wound for sound
Jan 1, 2011
3,081
4
38
36
French Creek, West Virginia
My LLY started off that way before it started puking coolant out at an idle. Most likely it's your HG's, but only time or a tear down will verify it. In my experience, you're better off doing the cheap easy diagnosis and then tearing it down after that. Better safe than sorry.
 

blackLTZ

Member
May 6, 2016
154
0
16
South Texas!
I think I will be getting a new one, but if it was a head gasket there would be compression and there's none it still holds pressure.
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,733
305
83
Boise, ID, USA
I'm not sure if there is a GM spec, but what I do is put 15-20 PSI in the cooling system, then walk away for 30 minutes. It shouldn't go down in pressure at all. If it has gone down by more than 1 PSI, you have now pushed a LOT of coolant into/out of somewhere. If you don't see any visible external leaks, rotate the motor over by hand and see if it hydrolocks. If so, pop glow plugs out and see which cylinder is full of coolant.

For what it is worth, oil analysis is really good at finding coolant residue in the oil. They have always seen signs of coolant before I noticed it going down.
 

nick31

New member
Apr 14, 2016
32
0
0
check your block heater, they weep and don't tend to leave a trace on the ground when they do
 

Hoffie

New member
Mar 10, 2015
212
1
0
Far East LA - aka Phoenix
My engine never left puddles of coolant either, until the radiator blew apart. Then after that it blew the top radiator hose off once and it would spew out of the recovery bottle while driving down the road. Never did show signs of water in my oil nor did I lose power. Now with a new radiator, lower hose, recovery tank, head and gaskets I get a sucked upper hose every day.
 

IOWA LLY

Yes, its really me
Feb 23, 2007
2,275
4
0
My engine never left puddles of coolant either, until the radiator blew apart. Then after that it blew the top radiator hose off once and it would spew out of the recovery bottle while driving down the road. Never did show signs of water in my oil nor did I lose power. Now with a new radiator, lower hose, recovery tank, head and gaskets I get a sucked upper hose every day.
Replace your coolant cap. With all the crap you purged out through your cap it's all gunked up. Some people clean them out using hot soapy water as well.

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