My LOW COOLANT light came on in my dash so i continued on home in the truck i noticed that the temp gauge was very erotic moving from 210 back down to 170-180 range something that the truck never does. So i put coolant in it 1/4 gallon was need to bring it up to the cold mark this mourning so i went for another drive the samethisng this time no low coolant light but the guage still would go up to 210 (never higher) on a hill or something that the pyro would stay at 900 or so for 20-30 seconds upon topping the hill or letting out of the throtle for a second or 2 the guage would jump down agian to the 170 range .. Any ideas?





the only thing i have hooke up is the quad 215 dont know if its related but i sent my edge box back for the monitor update so this is the only time ive ran the truck without both of them in about 15000 miles . like i said this may have nothing to do with it .


Edited by: SmokinMax

Kyle, Give me a call got some info for you.

Have you had the cooling system serviced or emptied recently?

no never had any thing done to it hoot

Do the simple stuff first.

Does your tank get pressurized constantly?
Can you smell combustion fumes in the coolant tank?
Is the coolant clean?

Any restrictions in the front of the truck causing air blockage?

The first mechanical thing to do is change the thermostats. Very easy to do and only costs $25. I posted on this recently.

I gotta wonder.... is it pushing any coolant out the overflow? Hoot, did you ever get yours figgered out? Just an air pocket?

no coolant out the over flow ....today i hooked up attitude and the engine temp on that doesnt fluctuate much at all ....so the thermostat would be the best cheaspest way to start?

no coolant out the over flow ....today i hooked up attitude and the engine temp on that doesnt fluctuate much at all ....so the thermostat would be the best cheaspest way to start?





Cheap and easy ....

Hate to rain on anyones parade but if your countinuing to see low coolant and or "burping" you have a leak in the combustion to coolant arena ....
http://cache.eastwoodco.com/images/P7528.jpg

Tester (http://www.eastwoodco.com/itemdy00.asp?T1=46134&I1.x=48&I1.y=69)

Mac http://www.dieselplace.com/forum/smileys/Unhappy.gif Edited by: Mackin

I gotta wonder.... is it pushing any coolant out the overflow? Hoot, did you ever get yours figgered out? Just an air pocket?

Now that you brought it up.... yes! It was an air pocket that came out by parking the truck up hill after a 40 mile drive. When it cooled down the coolant level dropped and no pressure in the tank. Added 1/2 gal and has been rock solid all week.

For those that wonder.... tree fell on truck. Radiator smashed. After the truck was fixed coolant system was refilled. It can be a bear getting the air out. It may be because I park facing downhill every morning.


My symtoms were...
Unstable coolant tank level
Coolant exiting resevoir overflow
Intermittant eng temp drops
Pressurized resevoir
Intermittant LOW COOLANT light

When the truck was cooled down, the tank was low. When I opened the fill cap the tank would fill up so fast it came out the overflow. So I couldn't ever add coolant. It wasn't using any.

GMC-2000-Dmax (TONY) suggested that I park the truck on an incline. That did the trick.

That was two weeks of "Uhh Ohh"

Does anybody know... Is there more than one bleed screw? I never got air out the thermostat housing screw and if you look at it.. it's above the closed thermostats so how can it let air out of the block water jacket? The T-stat housing is connected to the top of the radiator. Edited by: hoot

... the temp gauge was very erotic moving ...





Darn, I wish my truck was that dirty.....http://www.dieselplace.com/forum/smileys/Big Smile.gif


Later....

I used to drill a small hole (1/2 or smaller) in the thermostat. This let the air bleed through and allow it to br bled out or work itself out.

I used to drill a small hole (1/2 or smaller) in the thermostat. This let the air bleed through and allow it to br bled out or work itself out.

Interesting. I guess it depends on where the air exits. The thermostats do open during heat up so the air should find its way to the T-stat housing but it doesn't.

Also... I'll look again but I believe the rear T-stat has two vent holes in it already. Manual says to install that one with the vent holes positioned to the rear. I think the real problem is the air gets trapped inside somewhere.Edited by: hoot

We used it when we had problems with an air lock under the t-stat which kept it from opening. Sounds like that is taken care of with the D-max. Maybe the turbo cooling line gets airlocked, as it has a t-stat as well.

We used it when we had problems with an air lock under the t-stat which kept it from opening. Sounds like that is taken care of with the D-max. Maybe the turbo cooling line gets airlocked, as it has a t-stat as well.

Is that what that valve is? I saw in the troubleshooting sequence to test that valve after checking the main thermostats.

Funny you guys mention temp. fluxuation. My trucks temp was doing fairly rapid changes from 170 to 210 in 39 degree air temp. I've never seen this before and I was just driving unloaded.

Is your coolant level OK. Sounds like one t-stat is opening and closing. I have never seen mine do that - usually stays on 200. I do run the grill part of the winter cover at those temps, which might make a difference. Don't know off the top of my head what the opening temps are, but I will look in the fully illustrated shop manual.

Today mine went off again... coolant tank under pressure... coolant out the overflow... engine temp fluctuating.

Ordered the kit MAC referenced.

'Hate to say it, but that seems like a good idea. Sounds like cumbustion gases in the coolant. If so, bad news!

Now taking appointments for headgasket service. 2 day turnaround time for both sides. One day for one side.http://www.dieselplace.com/forum/smileys/Ermm.gif

Boys I know all about the headgaskets, my truck went down and it was the headgasket. And it ended up warping the head cause I got a new one. But it was down 8 weeks, that sucks very badly. Take Care And Have a VERY MERRY CHRISTMAS TO EVERYONE!