ikeray

As the title says, when I turn off the car after driving for 1hr+ my overflow tank is just bubbling, no coolant is disappearing, no white smoke, no chocolate milk for oil, just "blub, blub, blub" constantly after shutting off the car. Fans are working fine, secondary fan kicks on when a/c engaged, w/o a/c engaged kicks on after car has been running for a little while. Car doesn't overheat, needle sits at 3:30-4 on the vertical gauge, well below middle line.

The one thing to mention perhaps is that the fans don't run after I shut off the car like most hondas, it has never done it though for the length we have owned the car (10 years and 140k miles). The only time I've overheated was when a pipe sprung a leak about 2 years ago, and car didn't overheat for long (maybe 30 seconds as I pulled into closest gas station), and it wasn't on >H it was still approaching H.

For a while now its been a "since its not broke, leave it be" situation, but now that my bimmer is overheating, I'm paranoid the accord is going to as well...

sgraham01

that's strange. I guess you could possibly have air in the system and/or a faulty radiator cap overpressurizing the system. it's probably happening while you're dirving, but you just can't hear it. with the car cool, open the rad cap and make sure the radiator is completely full, and replace the cap with a new one. There is also a bleed screw near the thermostat housing that will bleed off air in the system. while the car is running, open the bleed screw and keep it open until only fluid comes out, then close it. Then proceed to fill the radiator.

gokooljapan

Possible faulty thermostat stuck shut. When thermostats break, the break closed. When this happens, the coolant has no where to go but to boil back into the overflow tank...hence you hearing the boiling.

When was the last time you replaced the thermostat?

Start at the easiest and least costly first.

1. Air in system
2. radiator cap
3. thermostat
4. clogged radiator

etc.

ikeray

haven't replaced T-stat in a while, will do it when I do the timing belt in the next 6-12 months.

the radiator had room in it, hadn't checked it in over a year or 2 when I had an overheating problem (broken hose somewhere back in the engine area) that my mechanic topped it off for me, I guess he didn't put enough coolant, or worse, I have a seeping/blown head gasket, probably more-so seeping as I'm not overheating. put <1/4 gallon distilled water both radiator and overflow, sound seems to have gone away. debating draining the prestone and putting in the Honda blue coolant I got from the stealership for $10, might just wait until I do the waterpump/timing belt as mentioned

again, thanks for the help guys, let you know if more coolant goes missing if it was just improperly filled