My 97 Odyssey’s radiator began to lose some coolant for the first time and I noticed that around the top of it about where it curves there is a foam border soaked with coolant. It does not seem to be coming from the cap or anywhere obvious when I looked around it from above and below. I’m guessing but is the top of the rad put on with a gasket that is releasing coolant on me and that accounts for the loss?
Yes, there may be some type of gasket between the plastic end tanks and the aluminum core, but it is not replaceable. You’ll need a new radiator. Check out how much they are at places like Autozone.
The foam stuff that is soaked is there to deaden vibrations to prevent damage to the radiator and, more importantly, noise which may irritate the owner of the vehicle. You probably have a crack in the plastic tank. Even if it is just leaking around the crimp of the core to the tank, you will need a new radiator. Now would also be a good time to replace your radiator hoses, to prevent further problems down the line.
I guess it might be time considering it is 13 yr old. May I assume I can get by for a while with the leak gradually getting worse or will it suddenly turn into a tow job?
May I assume I can get by for a while with the leak gradually getting worse or will it suddenly turn into a tow job?
Yes, it could go either way. The gamble is up to you. If while this is going on, you let the engine overheat, the cost of the radiator will be a minor amount compared to the rest of the bill.
Plastic has a nasty habit of shattering, so a big chunk could break off and spoil your day.
Tow job? Heck, it could turn into a sudden hemorrage on the highway and an overheated and destroyed engine.
I recommend you get it fixed.
The pressure cap on top of the radiator includes the gasket you are asking about. The cap should have been replaced new with every coolant change, and if it has never been replaced, you are way overdue. Maybe you are way overdue for a coolant change as well? You have inspected the leak and say you don’t believe the cap is leaking, but if the cap is old, try changing it and see what happens. If the new cap doesn’t help, get it into a radiator shop.