I recently bought a '03 cavalier and the engine is coming up on 300k miles on it. The car runs great, shifts fine, heat and a/c work great. There's only a few issues with the vehicle ( bad struts, small dent and some paint chips). But there's one major issue I'm facing and I can't seem to find the culprit and that's a massive coolant leak. When I first realized I was going through too much coolant I first replaced the coolant tank and cap because they were in bad shape, the cap wouldn't even come off and it had to be pried off with a screwdriver. Even after new tank and cap ( the cap still won't come off without prying off ) I still have the leak. On average I go through one container of coolant per week! I don't have any white smoke, my oil isn't foamy or discolored, there's no overheating. As I said previously, this car runs great. I've checked all my rad hoses and they seem to be okay but I am considering replacing the inlet hose because of some grime surrounding the snap ring. Yesterday I thought maybe I had air pockets in the coolant system so I filled the tank and let idle for about 10 minutes then all of a sudden there was massive bubbling and smoke coming from the coolant tank. I let it idle until it stopped and put the cap back on. Later that night when I left work, I made it half way home and my coolant light came on and the tank was completely empty! I don't know if this is a head gasket failure, water pump failure, radiator failure..I'm completely lost and I honestly need some help or insight into this. Going to the garage isn't an option because this is my daily now so I'm going to have to fix this myself.
Is there any signs of coolant in the engine bay or on the ground?
No there are no signs of coolant puddles on the ground or anywhere under the hood.
All it takes is a pinhole to go through a lot of coolant. To check your water pump loosen the belts and try to wiggle the pulley, any movement in the bearings is to much movement. Also, ordinary table pepper is a temporary fix.
Well, I would suggest a compression test to determine if the head gasket is the leak point. if it is and while you have the head off replace the timing chain and gears the water pump and chain and all tensioners.
But before all that have you looked in the passengers footwell for coolant, a bad heater core will be a point of exit for the coolant, but your statement about the smoke after running for 10 miutes and then the tank empties points me to head gasket or cracked head or cracked block, hopefully just the head gasket.
Yeah I'm with Steve, sounds like a head gasket to me...They do have a tester that you could put on the tank to check for combustion gases but I bet if you pull the spark plugs you might see some evidence there. I just had to do head gaskets on my fathers f250 desiel, same kinda issue, loss of coolant, ran great. The other thing that makes me think is the having to pry the cap off, sounds like you might be creating a vacume situation in the cooling system and that would make the cap hard to remove, is there any sound of air rushing into the tank when you have to pry it off?
