2005 Duramax, Head Gasket? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Nima** · 04-28-2022, 10:03 AM

Hi:

I am the original owner of this truck with just 115,000 miles on it. Yesterday, on my to work, it gave me low coolant level sign. Truck ran fine with temp never exceeded 180 degree (that is my normal temp since I have V2 mod on it). I had the heather for a short time and it was blowing warm air as well.
I parked the truck at work and after about 10 hours or so, when I wanted to head home, I thought to check the coolant level. Since the reservoir looked dirty and I couldn't see inside very well, I tried to open the cap up. Boy! it was tight! When I manage to open it, some coolant puked out of it. I bought a gallon of Dex-cool, top it off (got about 1/2 gallon) and drove home with no issue. Parked it over night, checked the upper radiator hose, it is soft and there is no coolant leak. I also don't really see any white smoke on start up.
So, I have been reading a lot and it seems most people pointing at head gasket. I have an edge tuner on this truck which has always been set at level one, nothing crazy.
I plan to change the reservoir cap to see if that is the issue. Any other ideas?
The EGR has been blocked on this truck from 1st year.
Thanks

**biketopia** · 05-04-2022, 07:13 PM

Definitely try a new GM cap, been known to cause issues on the LLY. They are also known to pop head gaskets but you might be lucky and just need a cap! The soft upper hose after sitting all night is a good sign. Get it full of coolant and a fresh cap and keep an eye on it. Also look into the mouthpiece mod, something about the turbo mouthpiece was restrictive on those and lead to issues which resulted in overheating. Putting an aftermarket one on or doing some mods to a stock LBZ mouthpiece would do the trick.

**Nima** · 05-05-2022, 06:47 PM

Thanks.
I have the Banks cold air intake system. Since I did the auxiliary cooling system (the V2 system) when the truck was just couple years old, my gauge (the dash and my Edge) rarely gets close to 200.
I got a GM cap but I had not had the chance to drive the truck yet. Crossing my fingers!

**Nima** · 05-09-2022, 10:00 AM

Update:

I changed the cap, drove the truck for about 50 miles, let it sit over night and the next morning the upper radiator hose was still soft, the coolant level was were I filled it before and when I took the cap off, there was minimal pressure in the system with no puking coolant

I hope that is all needed at this point, crossing my fingers!

**biketopia** · 05-09-2022, 02:52 PM

Woo!! Hopefully you're good to go

04-28-2022, 10:03 AM	#1
Nima Blue 67 Join Date: Apr 2004 Location: Western WA Posts: 1,169	2005 Duramax, Head Gasket? Hi: I am the original owner of this truck with just 115,000 miles on it. Yesterday, on my to work, it gave me low coolant level sign. Truck ran fine with temp never exceeded 180 degree (that is my normal temp since I have V2 mod on it). I had the heather for a short time and it was blowing warm air as well. I parked the truck at work and after about 10 hours or so, when I wanted to head home, I thought to check the coolant level. Since the reservoir looked dirty and I couldn't see inside very well, I tried to open the cap up. Boy! it was tight! When I manage to open it, some coolant puked out of it. I bought a gallon of Dex-cool, top it off (got about 1/2 gallon) and drove home with no issue. Parked it over night, checked the upper radiator hose, it is soft and there is no coolant leak. I also don't really see any white smoke on start up. So, I have been reading a lot and it seems most people pointing at head gasket. I have an edge tuner on this truck which has always been set at level one, nothing crazy. I plan to change the reservoir cap to see if that is the issue. Any other ideas? The EGR has been blocked on this truck from 1st year. Thanks __________________ 1953 GMC 3/4 ton: current project 1967 C20: 5.3 voretc with T5 conversion, 4 wheel 8 lug disc brake 1972 Nova: my 4 door sport sedan! 5.3 voretc + T5 conversion. drivable project, FUN!! 1979 Camaro Z28: 5.3 vortec conversion with build TH350: drivable project, Fun to drive 1992 Camaro RS convertible (Z28 clone): 5.3 conversion with build T5: on going project 2005 Silverado 2500, 4x4 Duramax, original owner

05-04-2022, 07:13 PM	#2
biketopia Senior Member Join Date: Jul 2015 Location: Warrenton VA Posts: 1,008	Re: 2005 Duramax, Head Gasket? Definitely try a new GM cap, been known to cause issues on the LLY. They are also known to pop head gaskets but you might be lucky and just need a cap! The soft upper hose after sitting all night is a good sign. Get it full of coolant and a fresh cap and keep an eye on it. Also look into the mouthpiece mod, something about the turbo mouthpiece was restrictive on those and lead to issues which resulted in overheating. Putting an aftermarket one on or doing some mods to a stock LBZ mouthpiece would do the trick. __________________ 71 c-10 Long Bed, under the knife for a No Limit Engineering Wide Ride Chassis Pack and coil over static drop. 07 Silverado Classic 2wd 95 Camaro 427SBC/TH350

05-05-2022, 06:47 PM	#3
Nima Blue 67 Join Date: Apr 2004 Location: Western WA Posts: 1,169	Re: 2005 Duramax, Head Gasket? Thanks. I have the Banks cold air intake system. Since I did the auxiliary cooling system (the V2 system) when the truck was just couple years old, my gauge (the dash and my Edge) rarely gets close to 200. I got a GM cap but I had not had the chance to drive the truck yet. Crossing my fingers! __________________ 1953 GMC 3/4 ton: current project 1967 C20: 5.3 voretc with T5 conversion, 4 wheel 8 lug disc brake 1972 Nova: my 4 door sport sedan! 5.3 voretc + T5 conversion. drivable project, FUN!! 1979 Camaro Z28: 5.3 vortec conversion with build TH350: drivable project, Fun to drive 1992 Camaro RS convertible (Z28 clone): 5.3 conversion with build T5: on going project 2005 Silverado 2500, 4x4 Duramax, original owner

05-09-2022, 10:00 AM	#4
Nima Blue 67 Join Date: Apr 2004 Location: Western WA Posts: 1,169	Re: 2005 Duramax, Head Gasket? Update: I changed the cap, drove the truck for about 50 miles, let it sit over night and the next morning the upper radiator hose was still soft, the coolant level was were I filled it before and when I took the cap off, there was minimal pressure in the system with no puking coolant I hope that is all needed at this point, crossing my fingers! __________________ 1953 GMC 3/4 ton: current project 1967 C20: 5.3 voretc with T5 conversion, 4 wheel 8 lug disc brake 1972 Nova: my 4 door sport sedan! 5.3 voretc + T5 conversion. drivable project, FUN!! 1979 Camaro Z28: 5.3 vortec conversion with build TH350: drivable project, Fun to drive 1992 Camaro RS convertible (Z28 clone): 5.3 conversion with build T5: on going project 2005 Silverado 2500, 4x4 Duramax, original owner

05-09-2022, 02:52 PM	#5
biketopia Senior Member Join Date: Jul 2015 Location: Warrenton VA Posts: 1,008	Re: 2005 Duramax, Head Gasket? Woo!! Hopefully you're good to go __________________ 71 c-10 Long Bed, under the knife for a No Limit Engineering Wide Ride Chassis Pack and coil over static drop. 07 Silverado Classic 2wd 95 Camaro 427SBC/TH350



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.