[hunter8333]

I am really confused! I thought for sure head gasket failure? I have constant pressure on upper radatior hose. Coolant occasionally dumps out the over flow in resevoir. This started about two months ago. My mechanic took loose the lower radior hose. It lost a little coolant so I had to add some. I did not mix the coolant still using the orange stuff. I never really got the coolant levels back to normal. I would drive it and the coolant light would come on so I would add a little more. I fianally filled the coolant all the way up and put a bottle on the over flow hose to catch the coolant if it puked out. It puked several bottles of coolant out the first two weeks. I would check it every couple days and dump it out. After several weeks it stoped dumping as much just a little hear and there. I would switch tunes after fill ups tring to see which would get the best fuel milage. On my high tunes a little coolant would come out the over flow here and there but as I got to the lowest hp tune it dumped another whole bottle of coolant out the over flow. The upper radior hose is swollen all the time with constant pressure on it, so much that you can hardly squeeze it. It does not matter cold or hot. The coolant level is below the cold fill line by about two inches, but the low coolant light quit comming on. I thought for sure head gasket. Before we started to tear it down I went to the auto part store and bought a
Head Gasket Combustion Leak Test. We did the test and no combustion comming from the coolant resivor. I then tested the test by putting it near my exhaust. It instantly changed colors. Why do I have so much pressure in my cooling system? I have tried to bleed the air out of the system with the bleeder screw, it will bubble until you take the cap of the resivor the it has a steady flow of coolant. It has never run hot and it runs great. My heat works while cold and the engine heats normally while at idle. No other symptoms. If any one has experienced this or has any advice it would be greatly appreciated. Thanks!!

 

[duramaxthis]

bump for ya

 

[jmaz268]

bump for ya

this post was from march........btw

 

[TDFDiesel]

bump for ya

Working on your post count?

 

[DetailsUnlimited]

My 06 is doing the samething right now. Did a pressure test and nothing. Truck runs fine but pukes coolant out also like there is a air bubble somewhere in the system. Done to vac/flushes with the dealership and problem still there. Any ideas or did you fix yours?

 

[duramaxthis]

Working on your post count?

could give a shit less about my post count, will never be cool enoughto have 10,000 posts. was using google search and found thread and didnt look at date, curious as to what he found as i am chasing the same problem

 

[TDFDiesel]

could give a shit less about my post count, will never be cool enoughto have 10,000 posts. was using google search and found thread and didnt look at date, curious as to what he found as i am chasing the same problem

I was just giving you a hard time.

Who's the 10k post stab at? I've only noticed one person with that many posts on here, haha..

 

[duramaxthis]

I was just giving you a hard time.

Who's the 10k post stab at? I've only noticed one person with that many posts on here, haha..

wasn't meant as a personal stab, although now that you mention there is only two or three people in the five digit club

 

[warptonez]

Dealing with the same exact issue! No one has found a solution huh?

 

[New to me GMC]

Probably headgaskets. Testing the coolant for combustion gas isn't always full proof. Especially if you are dumping clean coolant in on a regular basis.

 

[DetailsUnlimited]

Mine was a blown HG.

 

[ScottM10]

Blown HG on mine too.

 

[05LLYCHEVY]

I am new here, first post.
I have a 05 LLY. It has heat issues when towing so I have changed out the turbo mouth piece, put in a cold air intake, Edge evolution with egt probe and 4" magnaflow exhaust. Now recently I keep getting a low coolant alarm. I haven't added much coolant though. The reservoir is always low when the truck is cold and there is always pressure on the reservoir. I take the cap off and the level comes up to right around where it should. Well over the last couple of days a new issues has started. When driving the coolant temp drops right off around 100 F. Then all of a sudden it will spike up to 240 F + then level out at around 190 F. Anybody have any ideas what might be going on?

 

[Hook'em_Horns!]

Once you start seeing the wild fluctuations in ECT (along with the heater not working) with the steady coolant loss (thru tank overflow) and retained pressure in the morning....all points to the final stages of Head Gasket failure.

Sorry.
With a full reservoir tank, at idle, you should be able to see bubbles appearing.

 

[05LLYCHEVY]

Is that with the cap on or off? Any idea what the cost would be to repair head gasket?

 

[Hook'em_Horns!]

On/off, doesn't' matter. You can pinpoint which cylinder(s) has failed via air pressure at each glow plug port, seeing bubbles flow in the tank when found.

22-30 hrs labor, plus parts. Which varies too, as you'll be into it so you might as well replace other things too if they're aged (water pump, t-stats, crossover hose, belt, pulleys, etc.) Lots of search info available on it, best parts sources, info for the DIY-er or not, etc.

 

[05LLYCHEVY]

Thanks for the info. Now just to find a good mechanic. Too big of a job for me.

 

[Robby05]

Thanks for the info. Now just to find a good mechanic. Too big of a job for me.

Where are you located?

 

[05LLYCHEVY]

Whitecourt Alberta

 

[cstephens93]

On/off, doesn't' matter. You can pinpoint which cylinder(s) has failed via air pressure at each glow plug port, seeing bubbles flow in the tank when found.

22-30 hrs labor, plus parts. Which varies too, as you'll be into it so you might as well replace other things too if they're aged (water pump, t-stats, crossover hose, belt, pulleys, etc.) Lots of search info available on it, best parts sources, info for the DIY-er or not, etc.

Hook'em whats the process for the air pressure test?