We really could use some input from experienced Duramax people on this ongoing problem. Here's the situation, I'll try to summarize:
Jan 04, bought "certified" 2001 Chevy 2500HD 4x4, crew cab, LT, with 57k miles, all stock. Ran great until 69k miles, starting smoking white smoke, and engine was, believe it or not, getting louder. Truck died while pulling empty horse trailer up a hill, message of Service Engine Soon, Diesel Specialities (not dealership) replaced fuel filter, still smoked like a son of a gun. Took truck to local dealership, told that nothing was wrong, that we just needed to run a couple tanks of fuel through it to clean it out. Two weeks later, back at shop still smoking, now we are told that it needs injector sleeves and injectors, all eight. Truck did not pass their test drive, terrible knocking, replaced fuel rail. After three weeks truck is finally ready, drove about 30 miles, got a low coolant light, sure enough when visually checking the coolant tank it's about 1/2 inch low, back to shop, they quickly burp it and send me on my way.

Now 100 miles since picked up from shop, hard to start, thought uh oh, checked under the hood, coolant was down about two inches from where it was when we picked it up from the shop, low coolant light, back to the shop, and this is where we are today:

We are being told that the thermostat is bad, that it was sensing a overheated engine and therefore sending too much coolant. Truck has never shown overheat on the guage. Does this make sense to those of you that have seen these kind of problems?

FYI: Only charge so far is for the initial no problem found, but now they are asking that we pay for parts (thermostat), they will pick up the labor.

Jeez, we really love this truck, pulls a horse trailer like nothing I've ever seen, my family of five take it to go skiing, decent gas mileage, but we've never had a diesel before, so we are a little ignorant and don't want to get taken advantage of. Thanks for whatever help you can provide.

By the way, your website has been a godsend for us. Thanks

2001 Chevy 2500HD, Duramax Diesel, 4x4, Black, crew cab, LT, all stock

I don't think theres anything wrong with the t-stat. Does it still smoke white? The coolant is going somewhere, nothing to do with the t-stats is my guess. They need to re-check their work. I haven't seen a dmax with a bad t-stat yet. Any techs fixed a truck with a bad tstat?

My dad had both of his changed on his '02 Duramax. I still don't see how being low on coolant would cause a hard start problem. How experienced is this dealer with the Dmax?

Both his t-stats were bad?

I think only one of 'em was bad but they replaced both anyway.

I would recommend having a cooling system pressure test performed. This test uses pressure / loss calculations to determine a leak / migration, in the cooling system, and will definitely show you if there is a head gasket issue. White smoke emitting from the exhaust is a pretty definite sign, the only flip side to this is a coolant leak into the intake tract.

I can count on all our hands how many times t-stats have been blamed for this concern, and I can use all the same fingers up again on how many times that has been wrong.

Head gaskets.

Ditto on the head gaskets! I had all 8 injectors changed on my 01 and then the same problem you have. After a huge battle, dealer replaced both heads and there were signs of a blown head gasket. I don't know why it happens around the injector replacement, but I have heard this before.

Head gaskets.

Its dem dang ol 'luminum heads I tells ya):h Just kidding. Head Gaskets...

Max how high does the compression ratio climb when the injectors start dumping fuel into the cylinders?

Just a thought.

Tell them to test the cooling system for combustion gases.... I had similar symtoms.. this test confirmed it.... Head Gasket


http://www.getdieselpower.com//my01dmax_files/combustion_leak/color_compare.jpg

Thanks everyone for you help. We picked up the beast on Saturday 1/15, the dealership replaced both tstats and swear it's "good to go". We took it for a 60 mile drive, smoke was minimal, seemed fine, today drove it 20 miles, smoking most of the way, checked coolant level, it's down about an inch from full, with cool engine. It goes back to the shop again, I will suggest that they check the heads and gaskets. Pretty darn tired of this!! Do Powerstrokes have these problems?

Do Powerstrokes have these problems? Oh, boy, do they! Lets just say that 6.0 liter's puke coolant anytime over 30 psi boost. Nuff said.

Max how high does the compression ratio climb when the injectors start dumping fuel into the cylinders?

Just a thought.Should have no effect unless it gets real bad then it will actually lower compression due to the oil so thin it cant seal the rings in the cylinder.


I am still saying headgaskets on this one...

:( Truck still in shop as of 2/5! Truck has been in shop for at least 45 days since first of December. Not usable since November 8th.

Dealership test drove truck for 80 miles until they "broke it" their quote. That was on 1/19, said that the head was cracked, they never ordered the parts because GM said to go back and check the injectors and sleeves again. They found injector #1 was bad, #2 was leaking because of a groove in the head.
They ordered the head this week, they state that it will take at least a week to get the truck back.

We have been lied to so many times by their "Service Advisors" that we just figure if their lips are moving, their lying.

Is this a case of an inept tech? Or faulty parts? What caused this latest problem. What are my legal rights? Has anyone had these kinds of problems for so long? We are not getting anywhere with GM customer service, or the dealerships corporate customer service agent, who can help us on this.

We are asking for a comparable loaner vehicle from GM, so far they are not cooperating. :help2:

Should have no effect unless it gets real bad then it will actually lower compression due to the oil so thin it cant seal the rings in the cylinder.

Eric, I just have to ask you to clarify this statement? Later! Frank