Coolant Loss - Tell me it is not the head gasket!!

[kwoody88]

Hey guys (and gals).

I am hoping that someone has experience this problem with a positive outcome. I have not taken the car to the stealership because I am afraid of what they will tell me

For some time now, I have been occasionally getting the "Low Coolant" warning, and adding a little bit of coolant. I have had no leak on the floor of the garage, and I took it to an indie mechanic and they looked the engine over (didn't perform any chemical tests or pressure tests) and saw no evidence of a coolant leak, and instructed me to keep my eye on it. It was a gradual drain and I stayed on top of it adding a little every couple of times I took it out (which is normally maybe 3x a month). The last time I tried to drive the car I was just running up the road 3 miles to the grocery store on a nice night, probably a month ago. I topped off the coolant before leaving the house, and on my way back from the store I got the "Low Coolant", and was noticing the temperature gauge rising rather quickly. I shut everything down and pulled over, let the fan run and cool the car, and then made it the last mile to the house and parked it. Haven't driven it since.

Yesterday, I decided the car needed starting, and to run a little while. I filled the empty coolant reservoir, and started it up, and backed it out of the garage so it could feel the sunlight and realize what it was missing! The "Low Coolant" message came on immediately, and I got out and walked back around to the front of the car and it was empty. Odd, right? So I topped it off again. And then looked under the car, for leaks. It was dry... This time the coolant drained more slowly, and after about 5 minutes the reservoir was empty again. By the way, all the coolant I have been adding is the orange GM coolant, 50/50 diluted mix. After it drained the second tank of coolant, and I just pulled it back in the garage and shut it off.

I checked the oil, and the level was maybe a little high (stealership may have put in too much after their last oil change?) and it was a nice amber color -- didn't not look like the chocolate milk I have heard it turns to when coolant and oil mix. The only thing I DID find was a puddle of water under exhaust pipes. I sopped some up off the driveway with a white paper towel and it had no color. I wiped around the tail pipes and it was clear. And I smelled exhaust before shutting the car off and it didn't smell sweet. So I don't think it is burning coolant, though it does seem like too much water going is being burned off.

What do you guys think? Could it be throttle body, or thermostat, or water pump, or something else? The coolant has to be going somewhere.

I have a couple of oil leaks... but I took this photo of dipstick and of the area around the oil filler neck to show moisture.

 

[Duane]

If its losing that much coolant that fast there has to be a major problem but i to would be confused with no puddle under the car or a noticeable rise on the dipstick that doesnt make sense. Has to be one or the other.

 

[kwoody88]

If there was coolant in my oil, though, wouldn't the color be off? It has me very confused, too.

 

[airmike]

If you suspect head gasket, I would go to an auto parts store and they will have a coolant test kit that can tell if it has hydrocarbons in it. You don't have to buy the kit, just the chemical and pay a refundable deposit. Make sure you haven't just added coolant to the car or the test wont be accurate. If you have an external leak it can evaporate fast enough not to leave a puddle on the ground, but you should smell the coolant at sometimes from outside the car. It should leave a trail kinda white with a blue or green tint from the leak down the engine. The trail can be hard to find.

I would hate to see a head gasket problem on these cars, but surely it is not the major deal of the sideways northstar engines. I have never heard but surely these can come out the top like the old days.

Northstars have not been known to let coolant into the oil with head gasket failures.

 

[kwoody88]

We took the cover off the engine and put it up on a lift and checked from above and below for signs of an external coolant leak and found none of that white/blue streaks where it appeared to have leaked. I will go by an auto parts store today and see about getting what I need for the chemical test of the coolant. The dealer is within 5 miles of the house and has XLR techs, but I just can't stomach horrible news right now! I have read of a couple other XLR's requiring head gasket and the dealer charged about $5,000. Yikes. Thats about the cost of a new engine (not installed, just the engine). Thanks for your feedback.

Just for the record, that car has right at 60,000 miles. I think 60,003 or so.

 

[kwoody88]

As it turns out, my uncle (who owns a body shop) spoke to a friend that used to work in the service department at the Cadillac dealer in Bowling Green and now owns his own shop. This tech says it is not an uncommon problem and not the first he has personally seen. The reason it is SO expensive is due to having to pull the engine out of the car. I went at lunch to check on the chemical test at advance auto and they were not aware what I was talking about. I think I am just going to try to get it to the cadillac dealer to verify that is the problem -- and just let them steal my $110 to test it.

 

[Crimson Pearl]

If I recall correctly, 2004 and 2005 model XLRs have a known issue with radiator leaks. Has yours ever been replaced?

 

[Stella]

First if you ran the engine till the low coolant light went on you might have added a big air pocket in the system when you refilled? Other than doing a coolant system pressure check try draining the oil you'll definitely see the separation if there's coolant in the oil. You should never have to add that much to the system unless unfortunately theirs something wrong. Good luck.

 

[mtrocket]

First if you ran the engine till the low coolant light went on you might have added a big air pocket in the system when you refilled? Other than doing a coolant system pressure check try draining the oil you'll definitely see the separation if there's coolant in the oil. You should never have to add that much to the system unless unfortunately theirs something wrong. Good luck.

True... engines nowadays cannot be filled simply by adding coolant to the overflow tank, especially if they are THAT low. There is a air release usually on the top of the thermostat housing, or thereabouts. Loosen this valve and keep adding coolant until all air is released out of the system. Oh yea... this is done with the engine running at idle.
Or have the coolant level checked and filled by a mechanic...

 

[fcarga]

When was the coolant last changed and by whom? Large air pockets are not uncommon when a
R&R of coolant is incorrectly performed. Also the system will rapidly overheat. There should be a
coolant system "burping" procedure for the car which you should try before taking it to the dealer.
Good luck!

 

[kwoody88]

The car is on the original radiator, and as far as I know, the coolant system has never been flushed. I asked last time I was at the dealer for an oil change, and they said I didn't need it yet. I have not tried anything to remove air from the system... but I am more than happy to do so if I can find that air release on top of the thermostat housing. I'll look for that this evening, and go get some more coolant. That would be fantastic. Otherwise my plan is to tow it up to its birthplace in Bowling Green and change head gasket and check everything out. If anyone has a photo of that air release for me to reference that would be great, too. I'm still learning...

 

[Stella]

I know nothing of a air release valve. The cap itself should release upon a certain pressure built within the coolant system. A way to purge the system is with the car not running top off radiated and overflow. Once topped off start the car and turn the heat on full blast. Eventually after about ten minutes of running the thermostat will open allowing full circle within the system. Let run for alittle while topping of the system as need be. Once the level holds in both the radiator and overflow you should be topped off. Didn't make clear that while running you should have your radiator cap OFF the whole time to let the air pockets bleed out. Don't worry you will not build any pressure so you won't get scorched. That should bleed the system. Once done you shouldn't have to top of again unless theirs other problems? Good luck

 

[mtrocket]

OK... checked my service manual; there is NOT a air release on the XLR. However, other vehicles I've worked on do. Here is the Radiator filling procedure as outlined in the service manual:

Make sure the drain cock is tight.
Slowly fill the surge tank with 50/50 coolant until level reaches the base of the tank fill neck.
**Monitor the surge tank level closely, The tank level will decrease once the engine is started.**
Start the engine and let idle... allow to idle for about 4 minutes.
Slowly fill the tank with coolant until the lever stabilizes at the base of the tank neck.
Run the engine 2000-2500RPM for about 2 minutes.
Allow engine to idle and add about 1 liter of coolant to the surge tank.
Install the cap.
Allow engine to cool.
Top off coolant as necessary.
Check concentration of coolant using coolant tester.

 

[micropimp]

Have you checked your passenger side of the carpet? I have a coolant leak from my heater core. Bypassed it and it was fine after.

 

[kwoody88]

I'll try following that procedure this evening. If it got that empty, though, something still has to be going on... I haven't actually messed with the radiator at all, just the reservoir.

I haven't checked the floor board, but I haven't noticed anything. I haven't had a passenger in there in several months. I did have to change a fuse from that fuse box and it was all dry then.

 

[fcarga]

The "burping"/purging may need to be done more than once. If this does help with your problem,
I'd really suggest that you get the coolant replaced--I'll assume that it has Dex-Cool in it, and it
needs to be replaced every 5 yrs or 100k mile.

 

[Stella]

All your filling and topping off is done through the reservoir. That's why it's easier to get air pockets if left not checked. I believe the total 50/50 mix is between 3&4 gallons.

 

[mtrocket]

All your filling and topping off is done through the reservoir. That's why it's easier to get air pockets if left not checked. I believe the total 50/50 mix is between 3&4 gallons.

Right on the money... capacity is 14.8 quarts or 3.7 gallons.

 

[Bgrieve1]

I just replaced mine. Myself. Want that hard and a new radiator on Amazon was around$100 . Saved a bundle