Does a slow leak signal the end for Faye's 432,686-mile Chevy?

Dear Car Talk

Dear Car Talk | Mar 01, 2009

Dear Tom and Ray:

I have a 1992 Chevy Lumina with 432,686 miles on it. I'm losing coolant. The "low coolant" light goes on on cold mornings and stays on for about one to two minutes before it goes off. The cooling/heating system has been checked by three different mechanics, who all have pressurized the system and have not found any external leaks. I've been told that the antifreeze is going out my exhaust. The car continues to give me incredibly good service, including averaging 33 miles per gallon on the highway. Thus, I'm reluctant to part with this car. To date, it still hasn't been nickel-and-diming me. I just top off the radiator with antifreeze before I turn on a cold engine (a little inconvenient, but doable). What are your thoughts? Is there something I can repair, or should I just be giving my car a regular drink of antifreeze? Thanks for your help. -- Faye

TOM: It's great that it hasn't been nickel-and-diming you, Faye. Because it's about to start thousand-dollaring you.

RAY: If you're burning coolant, you have a blown head gasket, a cracked head or a cracked block. None of those is trivial.

TOM: Right. My brother's got a cracked head, and look how bad he's running!

RAY: The problem is, it's hard to know whether it's a head gasket, the head itself or the block until you get it "under the knife" and see what you find. So, you won't know whether you're in for $500 or $3,000 until the engine's in pieces.

TOM: And with your car's mileage approaching that "round trip to the moon" milestone, I'd be reluctant to spend a lot of money on major engine surgery. You certainly can do it, but with that kind of mileage, something else major -- a transmission, a rack and pinion, an air-conditioning compressor or the frame -- is likely to fail relatively soon. And you don't want to put $1,500 into a new head only to have to junk the car a month later.

RAY: So you can take one of two approaches. Approach No. 1 is the scientific method. You take the car to a mechanic you trust and ask him to examine it from stem to stern -- as if you were going to buy it now, as a used car.

TOM: If he tells you that the rest of the big, expensive components appear to be in decent shape, then you consider either rebuilding your engine or replacing it with a used engine from a junkyard.

RAY: There's some risk in that. But it's less risky if you have the car thoroughly inspected before making a decision. And if you get another year out of it for $1,500, that wouldn't be bad, right?

TOM: Approach No. 2 is the "fate" approach. In that approach, you acknowledge that this car's days are numbered. And that someday, the engine is going to overheat and fail suddenly and catastrophically. And it's going to strand you out on the road.

RAY: If you choose the "fate" approach, we'd recommend several things. (1) You keep a close eye on the coolant and refill it regularly -- just like you're doing now. (2) You make sure you have an up-to-date auto-club membership so you can have the car towed to the junkyard when it dies. And (3) you relegate the car to short trips, and rent a car when you need to drive a long distance so you don't get stranded far from home.

TOM: And in the meantime, keep your eyes peeled for your next car. You know, a nice '93 Lumina or something. Good luck, Faye. And good for you for keeping this one running so long!

Get the Car Talk Newsletter

Got a question about your car?

Ask Someone Who Owns One