blown head gasket on a Duramax???

[infinitymike]

Anyone have any experience with a blown head gasket on a '04 Duramax Diesel?

My truck has been saying "low coolant level" on the dash display since the summer.
I added about a gallon in the mid summer and the display never went out.
I thought I had to do something with pressing the pedals in a certain sequence to clear the code but couldn't find anything in the manual.
So I kept driving like that.
Even though its been real cold for a while now, I just had some problems with the heat on Tuesday and today.

The truck had been running close to an hour and it was still blowing freezing air.
But then what happens is all of a sudden the temp gauge jumps from being bottomed out to 210* and whamo hot air comes blasting out.
What did happen ONLY on Tuesday was I shut it down to go into a lumber yard and a huge amount of liquid came pouring out in front of the passenger front tire.

I first thought it might be a thermostat but my mechanic says its probably the beginning of a head gasket issue.
We opened the overflow container and a lot of air came out and it was low on coolant. We added a gallon and I drove away. About ten minutes later the heat came on.
When I got to my destination I left it running and checked the radiator hose. It was rock hard.

I went back to him today and the hose was rock hard again. He opened the overflow container again and it was very pressurized.
He tested it with a kit that you pour a liquid into two separate tubes that gets connected by a rubber fitting and then stick it in the overflow container. If there is exhaust fumes in the system it will turn yellow for gasoline and green for diesel.

But nothing happened.
He still feels that there might be a small pin hole in the head gasket and what is happening is that the coolant system is getting pressurized. Unlike a gasoline engine that will start to burn it and blow white smoke a diesel has such high compression that it pressurizes the system and it will blow out the overflow container.

We will just keep an eye on it for now,because a head gasket job could cost $4-5 thousand.

 

[semipro]

Sounds like you have air trapped in the cooling system. Some vehicles have specific procedures for purging trapped air from cooling systems. There may be a small air release (bleed) valve located at a high point somewhere in the cooling system that you need to open when adding coolant.
If it were me I'd try replacing the thermostat and making sure that all air is purged from the cooling system.

Edit: check this http://www.duramaxforum.com/forum/general-discussion/156440-coolant-bleeding.html

 

[infinitymike]

I suggested to my mechanic changing the thermostat and flushing the whole system and he said no, he doesn't think that is the problem and doesn't want to spend my money.

 

[semipro]

Doesn't sound like a head gasket to me, especially if the the radiator exhaust gas dye test was negative.
A leaking head gasket will generally build enough pressure that steam and coolant will overflow out of the coolant reservoir.
I'm sticking with the trapped air diagnosis. You can easily forgo replacing the thermostat and just add coolant as described in the link I posted above.

 

[ironpony]

sounds like its time for a Cummins swap.

change thermostat, flush system and as was stated above fill and bleed correctly. also common for low coolant sensor to go bad.

 

[infinitymike]

Doesn't sound like a head gasket to me, especially if the the radiator exhaust gas dye test was negative.
A leaking head gasket will generally build enough pressure that steam and coolant will overflow out of the coolant reservoir.
I'm sticking with the trapped air diagnosis. You can easily forgo replacing the thermostat and just add coolant as described in the link I posted above.

thanks for the edit.
that sounds to easy to bleed the air. lol

 

[infinitymike]

sounds like its time for a Cummins swap.

change thermostat, flush system and as was stated above fill and bleed correctly. also common for low coolant sensor to go bad.

probably will go that route on my own.
I hear ya on the sensor but it definitely was low and it was low agin today.
Added about 1/2 gallon of water

 

[semipro]

thanks for the edit.
that sounds to easy to bleed the air. lol

I hope it works for you.
It would be nice to have heat again too.

 

[infinitymike]

I hope it works for you.
It would be nice to have heat again too.

so do I. luckily I do get heat.
It was only tuesday and today and only 1st thing in the morning. otherwise the heat was working just fine the rest of the day.

 

[ironpony]

check everything over really good, a small leak will be hard to find. also what I have done in the past is, leave the radiator cap on the first click so the sysem wont build pressure and see if you still loose fluid. if you do not I would lean towards a leak as opposed to head gasket. maybe pick up a pressure tester and pressurize the system over night and you might spot the drip, might not evaporate from the engine heat. good luck.

 

[NE WOOD BURNER]

infinitymike,
I would check out your radiator they are notorious for weeping. and allowing air into system. until then I would try a low pressure radiator cap and bleed the air out.
The serpentine belts can slip and not spin the water pump. idlers are really only good for 60,000 miles or so.

 

[infinitymike]

There is no real radiator cap per say.
The cap is on the overflow container.

I came out this morning and before I started it I checked the upper hose... Rock hard.

I slowly opened the overflow cap and it bubbled and exploded like a shaken bottle of champagne. Pissed fluid all over driveway.

The hose was soft but after 10 mins of running it the hose was hard again. Been running for 15 mins and no noticeable heat.

 

[NE WOOD BURNER]

Are your heater hoses hot?

 

[NE WOOD BURNER]

http://www.thedieselpageforums.com/tdpforum/showthread.php?t=26996

Some info for you looks to be a nice forum. looks like a very interesting cooling system.

 

[burnham]

Rock hard radiator hose sounds like a head gasket.

 

[higginscl]

Its definitely not a head gasket. If its still holding pressure by morning on a cold engine there is more than likely not a leak either. The radiator cap or surge tank cap in your case is set to vent at a set pressure. Get a radiator cap "surge tank cap" and fill the coolant up starting with a cold engine. Once its full leave the cap off and start the truck. Let it warm up with the cap off, you will overflow a little and thats normal. Once the thermostat opens you will have to add more coolant. Do this till the thermostat opens two or three times (youll know when your good cause the coolant level will quit going down when the thermostat opens). To help speed up the process and help purge the air out you can rev the engine to 1200 rpm or so. This will also help fill up the heater core.

 

[higginscl]

I forgot to mention that while you are initially cold filling it squeeze the upper and lower hoses to help burp some of the air out. It sounds like you have a bad air lock mixed with a bad cap. Once you get it filled properly then and only then can you check for a leak.

 

[NE WOOD BURNER]

I was told that the duramax has two thermostats also the forum above describes the two of them and their functions. Also if at anytime the coolant was filled with green antifreeze if it had red/pink in it it can cause blockages and corrision in heater cores and aluminum pipes. in the past you could run one or the other but mixing the two was a no no.

 

[Highbeam]

This is not a small block chevy. It is a VERY expensive and sophisticated engine. Get to a real diesel mechanic or a good dealer and spend the relatively small amount of money to dignose your problem. When things break on a diesel you are looking at several thousand dollars for each component. Stop guessing, you are further risking damage.

 

[greg13]

Ok Lets approach this logically.

Are you actually loosing antifreeze? If not than the gasket is not blown. Once you shut the truck down the cooling system still has pressure, that would push into the cylinder through the gasket.

Has a pressure test been done on the cooling system? If it holds pressure than the gasket is OK. I would sooner think that it is air bound or you still have a thermostat problem from the conditions you describe. You could try pressurizing the system 5-10 psi and loosen the HIGHEST hose clamp on the motor and slide a pick between the hose & fitting (usually a heater hose) and see if you have any air there, that is not the best way to bleed the air, but usually works.

As Highbeam said, these are not small block motors, find someone that knows them. Mistakes get expensive FAST

 

[infinitymike]

Are your heater hoses hot?

Yes. I do get heat. It was just twice last week that I had a problem getting heat.

 

[infinitymike]

http://www.thedieselpageforums.com/tdpforum/showthread.php?t=26996

Some info for you looks to be a nice forum. looks like a very interesting cooling system.

Thanks. I will read through that thread.
I actually joined the dieselplace.com a year or two ago for an electrical issue.

I copied and posted over there and the Funny thing is, everyone there immediately said its a blown head gasket.
No one thinks its air or a thermostat.

 

[infinitymike]

I was told that the duramax has two thermostats also the forum above describes the two of them and their functions. Also if at anytime the coolant was filled with green antifreeze if it had red/pink in it it can cause blockages and corrision in heater cores and aluminum pipes. in the past you could run one or the other but mixing the two was a no no.

Yikes. Over the summer when the low coolant warning appeared I had some green coolant laying around. About a half gallon and I added it.

I think I'm going to flush the whole system and see what happens.

I also read to bleed the system if any air you need to losses a thermostat bolt and allow any air out.

 

[NE WOOD BURNER]

I would back flush the whole system. Look into the second thermostat. As I remember from what I quickly read that it can cause similar situations. Ill check with my Bro when he returns from vacation he is a duramax guy. I got more experience with the 5.7,6.2, and 6.5l gm 6.9,7.3 ford and my favorite the cummins.
My 250,000 mile 5.3l gas runs perfect with a blown head gasket I can see it leak but it keeps on running. problem started with a bad plastic tank to core seal on the radiator kids overheated it. they filled with wrong antifreeze and whala I get silicone sludge throughout the whole engine blocked heater core.
How many miles you got on it?
Have you put any aftermarket hot rod goodies on it?

I have bought many a vehicle diagnosed incorrectly for a song. Not saying its not a head gasket, but many times its not.

picked up a Cherokee a few years back for 400 put an electric fan in and flushed system and I was in business.

 

[infinitymike]

Ok Lets approach this logically.

Are you actually loosing antifreeze? If not than the gasket is not blown. Once you shut the truck down the cooling system still has pressure, that would push into the cylinder through the gasket.

Has a pressure test been done on the cooling system? If it holds pressure than the gasket is OK. I would sooner think that it is air bound or you still have a thermostat problem from the conditions you describe. You could try pressurizing the system 5-10 psi and loosen the HIGHEST hose clamp on the motor and slide a pick between the hose & fitting (usually a heater hose) and see if you have any air there, that is not the best way to bleed the air, but usually works.

As Highbeam said, these are not small block motors, find someone that knows them. Mistakes get expensive FAST

I have to be losing coolant, because the overflow container is full when I fill it and then low the next day. There are no signs of any leaks in the driveway or when ever I park it.
I always back into spots when I park it so I always approach it from the front end and have never seen anything on the ground.
So the fluid is going somewhere. But I dont see any white smoke from the tail pipe either.

My mechanic has only done an exhaust gas coolant leak test and it came back negative to any exhaust gases in the coolant. But he said that doesn't always prove it one way or the the other. Isn't that just great.
We haven't done any other testing.