Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Camaro warning lights

I keep good maintenance for my car. Just had the 45,000 mile major tune up also. However, the engine overheating light came on the other day - said I should idle until it cooled down. I was just about to park, so I did that and left to do some shopping. When I came back and started the drive home the light came on again and indicated I should stop and turn the engine off. I drove two more blocks and put the car in the garage. I noticed what I thought was some leakage on the garage floor also. Next AM, I had it towed to the dealership since I’d checked the coolant dipstick and it looked EMPTY!. Dealership tested it out and could find nothing wrong - no leaks, no computer faults either. They sent me on my way and neither warning light has come on since. I’ve kept an eye on the engine temperature gauge and it hovers around 200F - mid range on the gauge. No further problems. Funny thing is, now my A/C seems to operate better! WTF?

You did the correct things (except perhaps driving it that extra two blocks), and I tip my hat to you for that.

The only possibilities I can surmise are :

  1. you have a possible leak that allowed the coolant level to drop. It could be only leaking when operating and hot (water pump seals can act this way. When the shaft is spinning and the coolant is pressurized they can leak, and then not do so once cooled and with the engine off [shaft not spinning]). When this happens there are usually signs (tracks) but I know not what the shop checked.

  2. your thermostat is hanging up. This is cheap and easy to change. I recommend doing this preemptively even if you never find the problem’s cause. If you’d like to test the old one after you change it, post back and I’ll give you instructions. It’s easy and informative.

I suggest you keep a good eye on the coolant level AND carry a bottle of premixed coolant (the proper stuff, from the dealership) along with some leather gloves (you do not want to scald yourself). If you find the coolant slowly disappearing, refill it and add some UV sensitive dye (sold at any parts store). It’ll leave a trace from the leak that’ll glow like fireflies under a “blacklight” (UV light, should come with the dye if you buy the kit).

Monitor your coolant, stay prepared, and keep up the good work.

coolant dipstick ? Also what year Camaro are we talking about here? 45k is awfully early for a major tune up.

It’s a 2011, and the 45k was the recommended mileage from the manual. I used the term dipstick for lack of a comparable term. There is a long plastic strip with sequenced holes attached to the cap that I assumed played the same role for the radiator. The coolant system is supposedly sealed and good for 5 years. It’s now been 2 weeks and no further problems. ~Mark

I’m looking at the manual now

and there’s nothing mentioned about a major service at 45k miles. At 50k miles there’s a transmission fluid change and an air filter replacement. But the first tune up isn’t scheduled until 100k miles, which is typical. Did your dealer “recommend” a service at 45k miles? Dealers will often recommend services that are not mentioned in the manual and are usually superfluous.

Normally to check your coolant level you simply visually look at the level in the overflow tank, they are almost always translucent with “min” and “max”. On this car apparently there is a dipstick for the coolant. I’ve never seen a car with one of those before. However the idea for checking the coolant level is pretty simple, you just remove the pressure cap and simply look to see how much coolant is in there. Anyway if your engine is overheating you want to turn the engine off, idling the engine doesn’t help because you’re not getting any coming through the radiator, you have a fan or two of course, but the engine will just heat soak in that scenario.

Good ideas above. Also make sure the radiator fan(s) are spinning rapidly when the coolant temp gauge starts to show overheating. It sort of sounds like a stuck thermostat. If it happens again and you find yourself in a situation where it starts to overheat and you can’t immediately stop and turn the engine off, turn off the AC and turn on the passenger compartment heater to max, with the heater fan on max too. That will provide some engine cooling at least.

I too have never heard of a dipstick for the coolant level. Since the system is pressurized I have to wonder how that works. I assume you are aware of this already but just in case, you should NEVER open up the coolant system on a hot engine.

I think the dipstick is in an unpressurized reservoir.

In my case the dipstick for coolant level would be my brother-in-law checking coolant level.

1 Like

On my cars, that long plastic strip or tube is for the windshield washer fluid, not the coolant.

Coolant reservoir dipsticks have been in use for almost twenty years, to question the validity of this would suggest someone has not opened hoods in a long time.