I have a 04 LB7, the day after I got it back from my Fuel Filter/Oil Change at the dealer it started saying low coolant. So I added more, a month or so went by and its started saying it again.. What should I do??

No visable leaks I gather? Then you'll have to bring it in and have them look for leaks and test for CO in the Antifreeze to rule out a headgasket.





Mac

The weird thing is the truck NEVER smokes white at all.

may have injector sleeve leaking or I have seen many leak at the heater hose o-ring seal at the t-stat housing.

No puddles under the truck

Maby just a faulty sending unit!? Is it low on coolant again?

Yes. If you are actually loosing coolant, make it a dealer problem. Keep it documented incase of future problems down the road.
Keep us informed, too.

I have a simular problem except mine is low this month, then full for a few months. Like right on the mark then low again, then several months of right on the mark.


60k and I've been having this problem all a long since new. Dealer could not find anything so instead of making payments on a truck that is sitting at the dealer, I drive.


Oh and prey.http://www.dieselplace.com/forum/smileys/Dead.gif

Powell.. if you continue to just lose coolant it's less likely there is a head gasket leak. Head gasket leaks seem to cause a multitude of strange coolant level and pressure changes.

Are you able to remove the fill cap when cold and not have any pressure differential?

How about inside your truck... any smells? Windows fogged abnormally inside? That would indicate a leaking heater core.

Next guess is water pump.Edited by: hoot

Check your radiator cap to make sure it seals and can build pressure. If it can not pressurize the coolant can steam off. You will not even see it. If that is good fill it up and check the upper radiator hose. GM is good foe pin holes in the upper hose. You wont see a puddle with either of those prob.

I have had a "slight" coolant loss where I have to add about 2" of collant every 3-4 months. Just discovered that the right side head gasket is the culprit. Having it done under warranty next week. Mine was a drip about the size of a quarter on the floor every once in a while.

the heater hose o-ring on the t-stat will leak into the engine valey.coud be head gsk. I would get it looked at....my guess it injector sleve...

Mine was the right side head gasket. It was very minor but would leak after the truck sat when hot. Would leave a mark on the garage floor about 1" dia. There were virtually no other symptoms other than I had to replace 2" of coolant every few months. Been doing that since the truck was new.

OH sh*t! This doesn't sound promising. Starting to notice a drip on the right side and it doesn't look like it's coming from the hoses or coolant resevoir. I hope it's not the head gasket. Leaves a 1" to 2" dia. droplet under the truck.

Like all said SHOP TIME an the sooner the better

I'd get it in. When they did the job they said the gasket was faulty. Mine was loosing fluid for quite a while, although not much volume at all. I was always wondering "where is it going?" I didn't realize that it was leaking every day until I coated the garage floor with epoxy and could see the red. On the old concrete it just was a dark spot that I usually associated with the ac dripping.


Mine was done by a commercial truck dealer and they came thru and did it on time. I had to leave it there two days though.


All is well in paradise again . . .


Note - it will show up quickly with a pressure test.


Edited by: Trader Jack

Damn.. 8 new injectors now this crap. It better end here!


Injectors were replaced at 81,797, sent in on July 2nd and got it back on August 23rd. Truck now has 86,130 miles. At least it's still under warranty.Edited by: 1BADDMAX