Hi, I just picked up my H3 yesterday and the engine light has gone on twice. I took it in and the service department stated it was some kind of cold-air pocket in the engine. They flushed it out and the light went away.

Tonight it came back on again.

Has anyone else had any engine-light problems on new H3s? The H3 runs great it's just the stupid engine light went on again and I don't want to end up going to the dealer every day for this.

cold air pocket in the engine? Only thing I can think of, for this explanation, is an air pocket in the coolant.
Does your service order from the dealer list any engine diagnostic codes?
When the check engine light comes on, it sets codes, that last for quite a while in the controller's memory.

My check engine light came on over a month ago and my H3 has been in the shop ever since! They claim that it has low compression on the number three cylinder and that they can't get the parts to fix it. I would not ignore the light.

You probably fall under the Lemon Law. If it's in the shop more than 14 days I think it qualifies.

OnStar diagnosed the problem.
Seems this is a new problem than my first.

Power Train
Malfuction in the Cooling System

They said to bring it in for service within 7 days.
I'll take it in tomorrow morning I guess.
I love this vehicle, but I wish that stupid light would stay off.

Could this be related to whether the H3 was sitting in the back of the lot for an extended period of time (never being started, etc)?

Could this be related to whether the H3 was sitting in the back of the lot for an extended period of time (never being started, etc)?

The salesman told me when they sit the batterys go dead ,cheap batterys.

Some complaining got me some better service, free rental, and free H3 floor-mats. H3 going in on Monday morning.

Put a big expensive battery in the H3, and guess what, if it is not run for a month or two, it will also be dead. Not saying the batteries are the best, and some are bad.
Problem is the parasitic drain from the number of computers, radio, etc., that must retain some sort of memory that drains these batteries when not started and run for a while. Add more accessories that require a constant drain, and the battery will go down faster.
Dealers are supposed to boost each battery, at least once a month; their failure to do so, is due to negligence on their part.

In answer to the original question, no, sitting in the lot will not cause a coolant system fault. Depending on the fault, it might just require a flush and fill to get all the air pockets out of the engine block. Sounds like when the plant filled it, the tank ran dry and pumped some air into the system.

Thanks for the clear explanation of my problem.
Much appreciated.

Just as a followup:
Turns out it was a bad thermostat.
The part came in and they replaced it.
All is well in the world now and I got new floormats for my troubles