2002 Cadillac DeVille with Anti-freeze leak, now all anti-freeze came out? while driving

Over the last three and a half years my information panel would show “check coolant level”. I would add a half gallon of 50/50 anti-freeze to fill it. I have used probably four gallons over this time doing this. Got my oil changed and the information “check coolant level” came on and stayed on even thought the overflow was full. I have never seen a leak anywhere. Then one morning went to drive the car and had to put in 2/3 gallon anti-freeze to fill it. Drove about 20 miles to appointment without an issue. Returned to drive home. Was about 5 miles into the drive down the interstate when the information panel started to flash several warnings. “Idle engine” I remember. I can’t think of the others right now. At the time I was focusing on where I could safely pull over and stop. I drove about 2 miles after the info started to flash. The anti-freeze overflow was empty. Added the 1/3 gallon to it and it just emptied out. there was a little bit of smoke like it was overheating, but not too bad. Got car towed. The tow driver actually started my car and drove it to park it after he got it off the tow truck. It was wet in the upper front area on the passenger side of car, Under the radiator cover too on the passenger side. I can not see where the leak is at. Maybe upper radiator hose? All I know is the anti-freeze leaked in the upper front passenger side. Not sure what to do. Should I replace the upper radiator hose, put in anti-freeze and start the car? I do not want to ruin the engine. Is it possible that when they changed my oil that moved whatever hose is leaking (If that is the issue) and it finally gave out?

Blown head gasket is my thought. Pull the spark plugs and spin the engine with the starter. Watch for coolant shooting out the plug holes. Run a compression test. I think you’ll find at least one cylinder very low.


Oh no! Engine has maybe 30,000 miles on it. A while back I had to replace the front ignition coil. The front plugs were not bad looking, I did replace them then. I think I could figure out how to do the compression check. Did one years ago,but on an old car. So I would have to remove the ignition coil to get to plugs again. Would I take out all front 4 plugs? What about the back four? Or are you saying just pull a few to see? Why did I never see any anti-freeze on the ground ever? That is a lot of anti-freeze. I have never had a car that I had to keep putting in anti-freeze.

A bad head gasket lets coolant into a cylinder, where most of it turns to steam and goes out the exhaust pipe. Sometimes there’s liquid coolant left in there, that might splash out the sparkplug hole, as Mustingman suggests trying.


Pull the oil dipstick out and see if the oil looks like this.

If it does, an intake manifold or head gasket is leaking.



I will go look. Prior to the day I had it towed the oil looked fine.

A pressure test of the cooling system should quickly reveal the source of the leak. Frankly, this should have been done 3 1/2 years ago.


I only recently learned about that test after I did my own research. I have asked many mechanics that obviously had no clue. I can not take it to have that done somewhere now unless I tow it, I assume. Can I do that test at home?

Yes. You can borrow a test kit at places like AutoZone (you pay for the kit and get your money back when you return it). But you will need to be able to see all the parts of the system so you will have to remove that cover over the radiator.


This is what the dipstick looks like now. I have driven 335 miles since the oil change. When I just turned the key to look at the mileage the information read, “change engine oil” and then " check coolant level" briefly and returned to “change engine oil”. I smelled the paper towel. It smelled like oil, but maybe fuel too?

This is the area the anti-freeze was on. The wetness now is rain.![2002%20passenger%20side%20where%20coolant%20was%201|300x500]


I removed the radiator cover to look at things after it was towed. It was wet on the under side on the far right end of it, passenger side. Thank you for the information.

If you’re going to borrow a pressure tester from the parts store, make sure you get the adapter.

Since the pressure cap isn’t on the radiator, you’ll have to pressure test the system at the reservoir. This adapter allows that.



Did you see my reply with the pictures? What do you think?

I think you need to take it to a competent mechanic and have it looked over.


Thank you. I was hoping to see if I could at least figure it out to decide if it was worth trying to fix. I also do not have a ton of money to throw into a car right now.

I only mention it because it’s alot to ask on a online forum how to do stuff to a car if you haven’t had too much experience in the first place when it comes to working on your own car.

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Maybe you can rent the tool. Take in your radiator cap - to see if they have the correct fitting for your radiator. The tool is a pump with gauge. You fasten it to the open filled radiator and pump it up, then watch the pressure gauge to see if the system is holding pressure, or leaking.

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Here’s the radiator for this vehicle.


I don’t see anyplace for a pressure cap. Do you?



I understand. Thank you. Most of my experience is on older vehicles. Right now both of my cars, the 1996 and the 2002 had to be towed home. I am trying to decide where to focus to get at least one car up and running. I am not a mechanic, but I know more than some. My brothers taught me. And others.I recently replaced the front ignition coil on the 2002. I have done some stuff. I do prefer to work on older cars that had carburetors and none of this computer stuff. Newer cars are nice, but not easy to work on.

I understand ya.

Well going off age I would assume you’d want to get the 2002 car fixed first

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