I bought my 2001 Duramax about 11 months ago from original owner with only 45,000 original miles. It now has 90k on it and about 2 weeks ago started blowing white smoke on warm idle. No loss of power, and balance check was dead center. No codes. No mods. There has been a consistent (not huge) coolant loss. The truck has original injectors.

Is it the head gasket?

 

is cooling sys getting over pressurized? alot of times you can see bubbles coming up inside coolant resevoir. you can pull glow plugs and check for coolant blowing out. make sure to disable injectors first though

 

Did you check the balance rates in drive or park? I would check them in drive. 90k is the average for injector life on an lb7 I would not be surprised if you have one or two getting worn. I've also heard of injectors going bad and balance rates not being affected. Are you getting any fuel in the oil? Mpg been going down? You smell raw diesel near the tailpipe? Is it a haze or more of a smoke? Might be worth it to get it to the dealer to check return rates.

 

Sounds like a hg bro. I got the same problem right now and no money to fix it

 

it may also be the water pump i had a truck loseing water at a very slow rate but not over heating i replaced the water pump witha rebuild and wish i would have replaced it with a new water pump the rebuild pump failed in a big way and caused head gasket leaks and lots of very expensive repairs i am doing right now along with number 7 injector cup leaking exhaust up through the coolant system boy big bummer i would check the water pump as it is running look at it from under naeth the truck and may be even have someone run the rpms up to about 2,000 and hold it there as you check the weep hole hope this helps

 

Thanks for all of the input...Seems either way, injectors or hg, it's money or time or both. I will check the water pump and have some more diagnostics run. This is a stupid question I'm sure, but, are any of the hg leak stop products worth anything?

 

In my experience that bars leaks stuff just buys you some time, I wouldn't risk gumming up the water jackets with all the problems dex cool is known for

 

Didn't help mine at all

 

If you want to do it on the cheap, and if you have time and know a buddy who is mechanically inclined you could do it for the cost of the kit and maybe a few beers afterwards

merchant automotive sells kits for about $600 with bolts, gaskets, basically every thing you need to do the job, aside from the tools

and if you can get ahold of someone who owns ALLDATA that will help too, it only costs $25/vehicle, and can tell you step by step how to do the job

 

I don't have the mechanical abuility