Jash2o2

I just purchased a used 2004 Cavalier about a week or so ago and it is already having plenty of problems.

The first and probably biggest problem I encountered was a few days ago when my low coolant warning light came on, but at the time I didn't know what light it was. I pulled over when my engine temp began to rise and after a good 40 mins or so at the gas station I checked the coolant level and noticed it was completely gone. I also noticed that the cap had come off! I bought a new bottle of coolant, filled it up, and drove for about 30 more mins. Just before I got home, the light came on again and once more, the coolant was gone. I filled it up again later that night and didn't drive it again until a day or two later. I took it to a friend of mine who just so happens to be a fantastic mechanic, but he is more of a Honda specialist. He didn't have the right equipment at his house to do a pressure test but other than that we couldn't really find any leaks. He did discover my second problem though. Since then I have still been losing coolant, but not nearly as fast.

It turns out that my radiator fan isn't coming on at all unless the A/C is on. That didn't cause my first problem though, since I almost always have the A/C on here in Texas. My friend thought it could be the coolant temperature sensor or something like that.

My third issue is that my gauges tend to act up and stick occasionally. Sometimes the tachometer doesn't work at all, sometimes my temp gauge sticks, and sometimes my speedometer sticks and jumps around. The only thing that seems to be fine is the fuel gauge.

My last issue is that my horn isn't working when I press on it. It isn't the horn itself since when I lock my doors with my remote key fob the horn honks. I wouldn't really mind but I can't pass inspection without it.

The fuses all seemed to be fine. I have a $1700 2 year warranty on it that only covers engine and transmission issues. I did buy the car as-is from the dealer though. I need to figure out what the best course of action would be.

Edit: We thought it could have been a blown head gasket but there was no discoloration in the exhaust, oil, or coolant and the car hasn't overheated except the one time when it ran out of coolant.

Chuzz

Check the neck of the radiator and make sure it isn't cracked of broken. I had a Geo Prizm several years ago with a similar problem and that's what it was. I had to get another radiator for it. That cured the problem. You don't mention that your friend checked the thermostat either. If it's sticking, that could also be the problem. A new one doesn't cost that much to replace it to start with. Just check it in a pan of boiling water before you put it in, to make sure it works properly. I've had defective thermostats off the shelf. Did you replace the radiator cap? The spring in it could be defective and not hold pressure on the system properly. You can get a pressure tester from your local Autozone in the loan a tool program and pressure test the system yourself. They should be able to instruct you as to how to use it and how to test the radiator cap too.

Jash2o2

Ya he would have checked the thermostat and a few other things but he doesn't know much about Chevys and he didn't have all that much time to look over it for me.

I don't think it's the radiator cap since the dealership replaced and refilled most things in this car, the cap included. We also got a new one and compared them and they both looked brand new. If you really think it could be my cap, I'll replace it just to be sure.

Now I do want to pressure test it but this car doesn't have a cap directly on the radiator. It's got a coolant reservoir that has the cap instead and my friend told me that his pressure tester didn't have the right end to fit on the tank. The guys at auto zone told me they weren't sure if their kit would work on the reservoir. I do know that they will let me rent their kit for about $75 and I get a full refund when I bring it back so I will try to do that.

Chuzz

That's the first thing I would try. And if that tank has a crack in it, that could be your problem. Have you noticed any leaks while it's parked after you've driven it? Since the dealer replaced the cap, don't bother with a new one. And your friend needs to realize that just because it's a brand he's not familiar with, that all cars operate the same way, regardless. Unless, of course if it's a diesel or electric. LOL

Jash2o2

There have been no signs of leaking anywhere. No puddles or dripping coolant at all from what we could tell. I plan on trying the UV dye leak detector to be sure.

Jash2o2

Ok, so far the UV leak detector isn't showing up anywhere so if there is a leak I can't seem to find it.

I've been trying to pressure test it but the attachment isn't sealing on the reservoir tank properly so I might need a new tank. It worked at first but the pressure was going out the overflow hose. Once I got that taken care of is when the attachment stopped fitting right.

Edit: *Update* - I replaced the overflow hose and did another pressure test. It held consistently at 15 psi. Either there is no leak or the leak only shows when the engine is at a certain temp. I don't know why my coolant randomly disappeared when it did but maybe it was just a fluke. Or maybe something is seriously wrong and I can't figure out what it is.