the case of the missing coolant

R-D · July 3, 2015

After I parked the truck last week the fan stayed on quite a bit longer than normal after the truck was off, I didn't think a whole lot of it at the time, but a couple days ago I got a "over temperature idle engine" warning on the DIC and watched the temperature go back and forth from dead center to max a couple times.

Looked at the reservoir and there was no coolant visible at all. Ran to the store in our other vehicle and bought 2 gallons of coolant. It took the full first jug and a bit from the second to bring it up to the full cold mark.

I couldn't see anywhere it would be leaking from - and I've had no pool on the driveway - but there was a definite coolant smell in the engine bay. The only thing I noticed was the visible corner of the rad that you can see (driver side) there was white residue along the top edge, not 100% sure if this is coolant or not but I suspect it may be.

Have an appointment for the Onstar module replacement (2G to 4G) next week so will ask them to look into it then, until then I'll keep checking and topping it off.

hurricanoday · July 3, 2015

Isn't this one of those things that can void your warranty if you know there is something going on and don't take it in immediately? (kind of like driving with no oil) I would take it in immediately or stop driving it till you can

DeePa · July 3, 2015

I had my rad replaced under warranty. Leaking from the pass side of rad. No puddles. Just a strong coolant smell if you're in front of truck

SkiDooNick700 · July 3, 2015

The fans keep running on these trucks even with the key off??

gone_fishing · July 3, 2015

Have you checked your oil level? If coolant were somehow getting into the engine the oil will appear milky.

HondaHawkGT · July 3, 2015

Yes check your oil now.

TJay74 · July 3, 2015

yes the fans can run with key off, the ECM/BCM controls the fan function even with no key on.

I would check the oil, if it is clean then there has to be a leak in the system somewhere. Dealer will find it and correct it.

foo.c · July 3, 2015

Watch for white "smoke" out the exhaust too.

R-D · July 3, 2015

Isn't this one of those things that can void your warranty if you know there is something going on and don't take it in immediately? (kind of like driving with no oil) I would take it in immediately or stop driving it till you can

Its a slow leak and I've topped off the reservoir regularly since I've noticed. The dealer actually noticed it was low and topped it off during my last oil change as well I recalled last night. Short of intentionally running with no coolant in the system or continuing to drive if overheating I couldn't see how they could possibly deny any warranty on this type of issue for waiting a few days until an already scheduled appointment.

The fans keep running on these trucks even with the key off??

Yes the fan can continue running with the key out/ignition off until the cooling system is at a sufficient temperature to turn off.

Have you checked your oil level? If coolant were somehow getting into the engine the oil will appear milky.

Yes check your oil now.

Thats one of the first things I checked, the oil was full and clear still (recent oil change).

I spotted a couple other posts on the forums here about rads needing replacement, will see if mine is the same issue.

Thanks.

Kent2500 · July 4, 2015

Its a slow leak and I've topped off the reservoir regularly since I've noticed. The dealer actually noticed it was low and topped it off during my last oil change as well I recalled last night.

Pretty darn simple to pressure test the system. When I had missing coolant with my 2000 Tahoe, I would only notice the visible leak when I put it under pressure (then the drips started at the water pump) and of course it wouldn't hold pressure.

DeePa · July 4, 2015

Dealership pressure tested mine, no leak found. Fast forward three weeks...they comment...you had a pretty big coolant leak...

No shit i told you that last time...

If you get a good service advisor...just use him or her. I slam them in the ratings too.

R-D · July 8, 2015

Radiator was replaced today, will pick it up tomorrow. Was told they've had a number of problems with the rad leaking on the '14s and the new one is a different part number so sounds like something has changed on it.