Diesel Place banner

Losing coolant

5K views 38 replies 11 participants last post by  Big Rack 
#1 ·
I keep laying coolant, I can smell it, there's never any puddles on the ground. Any suggestions on where to look?
 
#3 ·
Is your upper rad hose firm on a cold engine?
 
#4 ·
I'll check the hose tonight. I will say I had a real good leak yesterday morning but it was from my cap not being tight enough. It barely moved at all when I tightened it up. The auto parts store rents the pressure kits. May have to rent it.
 
#5 ·
Don't get carried away with the pressure. System is only rated for something like 13 pounds. I hate to say it, but you may have a head gasket issue. Check the tank to see if there's any sign of oil in the coolant and the dip stick to see if there's any coolant in the oil.

Good luck, and I hope it turns out to be something simple and easily repairable.
 
#6 ·
If it's a head gasket I'll be mad mo fo I just bought the damn truck! But I was afraid of that being a possibility. I've checked the oil and watched the exhaust for white smoke.
 
#12 ·
I drove mine for months with the signs of a bad headgasket and had ZERO traces of coolant in the oil analysis or white smoke. Once you have replaced the cap on the coolant overflow tank (Degas) if you are still seeing pressure on the system when its cool you have bad headgaskets. I ran several tests for combustion gasses in the tank and all came back negative, it didnt start pushing air into the system until it was hot and under a load.
 
#9 ·
Hard upper radiator hose in the morning.
Coolant being pushed out the surge tank overflow.
Erratic engine temperature and inconsistent cab heat.

Those seam to be the ones I see the most.
$4,000 - 5,000 is about the typical cost at a dealer assuming you just get the head gaskets done and nothing else.
 
#10 · (Edited)
ok,slow down,
first remove the rad coolent cap,[only after the truck has sat over-night] make sure its bleed and filled-up to the full mark,,leave the cap offstart the truck,let it idle with the ''heat/ac on high hot'',after 5-10 mins ck the coolent [is it still full?]top it off,do you have heat?,after it warm and doesn't need any more coolent,replace the cap[you might want to clean/flush cap with hot water/to clean it too]drive it for 10-15 mins and ck for leaks

this a good start,before going to a shop and pressure testing it

other thoughts can/did you wash the eng down lately,its a good way to find leaks too
 
#11 ·
Hard upper radiator hose in the morning.
Coolant being pushed out the surge tank overflow.

Both are good signs. And I do HIGHLY recommend you have a shop test it, since it could be the EGR (cheaper fix), but if you run the truck, heat it up to full temp, then shut it down overnight to completely cool, and check the upper radiator hose, if its hard, 99.5% chance its your headgaskets.

Now, that $7,500 job of mine. It was almost 40 hours of labor, included ARP headstuds (don't do this job without them) plus they pulled and cleaned all the injectors, and replaced the water pump (known to fail as well).
 
#13 ·
Thanks for all your help guys I'm layed up right now with some gombu sickness but as soon as I'm back on my feet I'll try all these tests. I'm a little scared though that's the last thing I need, is another high dollar bills but then again who actually ever "needs" that lol.
 
#14 ·
Well I couldn't take it so I went out and felt the radiator hose it was a little stiff I slowly unscrewed the coolant tank cap and it had a little bit of pressure on it. The truck has sat for about 14 hrs. Not good signs.
 
#20 · (Edited)
I tried to convince myself that it could be the EGR cooler and I have the perfectly good original one (blocked since almost new) that I replaced. It was a waste of time and money. I am packing for a move or I would offer to send it to you for a test, right now I have no idea where that particular box is.

I was seriously pissed at having to spend the money because some bean counter at GM cheaped out on a gasket, but.... its not my first round of GM's lousy engineering and crappy quality.
 
#21 ·
I'm going throug HG nightmare right now. Started off with that smell. Turns out the smell was actually small amounts of coolant that comes out of the degas tank while driving. The wind basically blows it off but you still smell it. Then it got to the point where when towing anything it would puke out about a gallon out the tank.

I just did the job including ARP studs and all. The Fing thing bubbles at idle still. I had the heads planed and pressure tested. So looking for cracks now. Inspect every square millimeter. Good luck.
 
#24 ·
While I agree that GM bean counters have screwed up a number of items, I'm not ready to blame them for the head gaskets. GM purchasing sends out specs to manufacturers who then come back with prices of items (in this case, head gaskets) that are supposed to live up to those specs. It's not unlike what the Army does. In some cases, it's hard to accurately predict the longevity of products, and it's most possible that the samples furnished by the supplier passed those tests anyway. In the case of the head gaskets, I place the blame on the company who manufactured them, not the bean counters at GM. Whether GM went back on the company for compensation is unknown, but you can bet they did for gaskets that failed under warranty. Out of warranty, there's not much GM could do.
 
#25 · (Edited)
Okay then, lets call it a collaborative screw up !


This is after all, the same company that was too cheap to put more than one key lock on a 4 door truck.
 
#26 ·
1STLLY, don't blame the headgasket per say.........

blame the cheap has headstuds that after time of heating up and cooling down have stretched....so, move from that blame to the piss poor cooling system that won't let the truck stay cool, and so it gets way too hot in a hot weather inviroment especially when towing a heavy load......AGH! it all just pisses me off too....
 
#28 ·
Considering the gasket design was changed and as far as I know the bolt design wasnt, my money is on the gasket with an award for the original bolts as a co-conspirator.
The heat issue has to have at least some small part in it.
 
  • Like
Reactions: Tom S.
#27 ·
I would also look closely at water pump. My LLY had a leak there that evaporated while running. Took forever to drip on ground overnight.
 
#29 ·
Ever heard of anyone just changing out the head studs one at a time and getting the gasket to deal back up? I know the gasket is probably shot but would it be worth a try? Even if it doesn't work you'd just be out time because the new studs would be needed when you do the head gasket. I'm actually thinking about buying a new set of heads a head gasket kit and the arp studs and just doing it myself.
 
#31 ·
Honestly, after taking a tour of the shop that did mine, and seeing all the work that went into the project, I would NOT attempt it.
35 hours of shop labor by professional deisel mechanics, not the GM dealership.
And if you are going in, you might as well pull and clean the injectors, replace the water pump too.
I think by just replacing the studs, you are going to find you waisted a bunch your time.....and we know that is valuable.
 
  • Like
Reactions: TiredFarmer
#30 ·
Both my gaskets blew out in exactly the same spot and from what I have seen, mine are like many others. There is no amount of clamping force that could pull them back to not leaking. Now, if I had one that had zero signs of a leak the idea of putting in the studs may have some merit but I think the torque sequence needed for the studs might be an issue.
 
#32 ·
I guess I'll just face the fact I'm screwed bought my first Duramax and thought I was doing the right thing avoiding the LB7 injector problems. Instead I get the head gasket problem. Not sure what's worse.
 
#33 ·
Easy answer, you don't have to keep replacing head gaskets/studs like you do injectors on the LB7, and you got more HP/torque.
 
  • Like
Reactions: Tom S.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top