NEED HELP FAST!! NO HEAT NEED TO PLOW

[Duramaxdiesel]

Ok guys I'm heading out to plow snow and I have no heat!! What could be the problem? A stuck thermostat or what? Any help wpold be appreciated. Thanks :mad: :mad: :mad:

[SteveO]

How cold and are you running the Winter Front Bra?

[Duramaxdiesel]

I'm just under 100 and I am running the front bra. I don't understand? Thanks.

[SteveO]

Have you actually touched the Upper, Lower and Heater Hoses to see how warm they are? Do they feel like 100?

If they all feel about the same temp, I would check the Thermostats..

[Duramaxdiesel]

I'd check it out but my dad just took the truck. He was mad as all heck and said "heat or no heat, that truck is gonna work." I'll look at it when I meet him at our yard. Thanks for the help SteveO and the fast reply. I'll let you know what happens. Nick.

[DmaxCC6spd]

I had a similar problem recently on a GMC Jimmy. First, what is the engine temperature on the gauge? It should be 180+. If it reads 180 or higher I would suspect something in the dash or HVAC controls, i.e. an electrical problem. If the temperature is under 180, I would check the thermostats (I think it has 2). I had an experience with my Duramax when I let it idle, after being fully warmed from a 100 mile tow with the grill cover on, the engine temp went down. Be sure to work the truck hard to generate heat.

Good luck.

[Duramaxdiesel]

Wow!!! Found the problem. Actually my dad did. He stopped the truck on the highway, popped the hood and said that there was a little switch near the air box. He pressed it then opened the rad tank and it practically blew up. A lot of pressure in there. Think it was an air lock. Well, there's heat now. Thanks everyone for the help. Only place I know of that you can get a reply in less than 2 mins.

[FirstDiesel]

Doesn't sound right. The "little switch" by the airbox is probably the filter monitor gauge and has nothing to do with the coolant.

As for opening the cap and having it explode??? I'd keep an eye on the engine and the coolant level. Almost sounds like a problem with pressure in the cooling system. That equals something like a head gasket.

[Maverick]

I had both head gaskets go out on my 3500. It was pressurizing the cooling system and blowing coolant out the overflow. My engine always heated up fast and the fan ran alot because the combustion gases were heating the coolant up along with engine heat. I plow also and never run the grill cover and can get my engine fan to come on while highway running with the plow on (lack of air plow). I would watch that coolant tank though. Sounds like a problem.

[Duramaxdiesel]

Hey guys, sorry for the delay in getting back.
So, now you've got me worried with all this talk about head gaskets going out. This was the first time that there was no heat and the first time the rad cap just about blew off. I let the truck sit over night then started her this morning with no problems. Will this problem come and go before the gaskets go south? Or should there be no heat all the time I start her in the morn? :confused: :confused:

[mackin]

Duramaxdiesel

Don't panic !!!!!You just may have a faulty pressure cap......

If your not losing or blowing coolant out of res. tank or any where else for that matter, chances are your truck doesn't have a major issue...I would get the cap tested or just get one, and keep an eye on coolant level, and as long as it doesn't (or hope it doesn't) reoccur, cause chances are the dealer can't repeat problem, comes to mind....

MAC

[Duramaxdiesel]

Mackin'

I checked out the coolant level and all seems fine. I'll order a cap though just in case. Thanks for the info. Also how would the dealer pressure the system to find problems? Can I do it myself? Thanks.

[mackin]

Duramaxdiesel

Pressurizing the system in your case I don't see how that would help...Seems your system may be building to MUCH pressure, so says what your explaining....Might have been normal....How long did you drive and idle before you say NO heat condition??

Is your upper,lower radiator hose collapsed in the mourning,cold???? On Edit; Or HOT running for that matter???

MAC

[ 01-06-2003: Message edited by: mackin ]</p>

[Duramaxdiesel]

Mackin
I'd say The truck was being driven for about 15 mins before I noticed no heat. I never thought to check weather or not the hoses were collapsed in the morning. I'll check next time.
What did you mean by hot running.
UPDATE: It happened again on Wednesday. Same scenario. The truck worked all night fine. I stop to eat after the run. Finish eating, I'm heading home on the highway and blam, no heat. The truck is at the dealer today. Hopefully they'll find out what it is. I have a feeling you guys are right about the head gaskets.

[Duramaxdiesel]

Dealer changed the two thermostats today. Doubt it'll help. You guys still leaning toward the head gaskets??

[IndigoDually]

T-stats stuck open is along the line that I was thinking.

Good Luck, John

[mackin]

Duramaxdiesel


I highly doubt it's the head gaskets if your not losing coolant that seems to be the first symptom of that problem.....Hope the T-stats did the job.....

MAC


The clarification on HOT is: Is the hoses collapsed HOT also.....

[Duramaxdiesel]

Well it happened again last night. No heat.
Brought it to the dealer and they just called me. They found a restriction in the cooling system. Somehow a little white seal like the ones found under an anti-freeze jug cap wound up in the system. :confused: I never added anything to the system so they think it happened at the factory :rolleyes:

They checked the head gaskets like you guys mentioned and said they were fine. I hope that this little problem is now cured.