Just a coolant leak or something else?

[ktacserv]

I have a 1996 Camry LE with 270K miles. Yesterday I noticed the heat gauge going up into the hot range while idling in the parking lot after a 45 min drive to work. My fans were on while it was getting hot. I turned the engine off immediately, no steam or noticeable adverse damage was done. Went into the building and let the car cool down for a few hours. Came back out to the car about 5 hours later and checked the radiator – it was full, cap was secure. Radiator is new within the last two years. Checked the coolant reservoir, it was completely dry. I added 50/50 coolant to the fill line. Drove 45 mins home in stop-and-go traffic and the gauge stayed within the normal range the whole way home. Car sat overnight for about 13 hours…I checked everything again before my 45 min morning commute. Radiator still full, cap secure and tight, but coolant reservoir was empty again (less than 24 hours later). Refilled the reservoir and got to work OK, but it seems that there is a big leak somewhere because I have to constantly refill the reservoir after each drive I take.

When I fill the reservoir, there are no noticeable leaks from the container itself. The one hose that I can see running to the radiator from the reservoir appears to be in good condition with tight seals. There are no noticeable leaks on the ground from any coolant leaking when car is hot or idling. Nothing is leaking within the interior of my car. (Maybe there are leaks I am not seeing?) I do not smell coolant in any way when car is running. Any ideas what is going on? I am assuming this is a coolant leak, but don’t know what else I should be looking for.

I need to know if this can be a DIY project, or if it is indicative of a larger problem and should go to the mechanic. If this is a decent DIY thing - any suggestions on where to get the parts or tips on doing the work would be great.

[Chris Crash]

Sounds like a head gasket starting to go.

[hill8570]

Is your exhaust white-ish or smell like antifreeze (sweet)? Does your oil dipstick and/or cap look more like a chocolate milkshake than normal oil? Either would be an indication of a HG failure.

You could also take a white rag and dab it around the radiator hoses (especially around the ends and the clamps) when the rig is warmed up, and see if you can see any antifreeze on the rag...it really doesn't take much of a leak to drop a pint of coolant in an hour. Do the same rag test of all of the other coolant hoses in there -- the two going to the oil cooler are failure-prone, and there are also some coolant hoses going to the IAC (under the throttle body) and into the firewall for the cabin heater.

You can usually rent a radiator pressure tester at auto parts stores -- might be easier to try to troubleshoot this by pressurizing the system while the engine is cool.