grunlowen

Can't figure out why the fluid in the radiator tank keeps going up and down. I tried messing around with the bleeder valve, but nothing came out other than some radiator fluid. Here's what happens:
- Run car (tested it with the cap off), and after a little bit the level of the tank goes up and down.
- The bottom hose is cold, and after a while, the t-stat opens and the bottom hose gets hot.
- Oil temp is well below 130, and the other temp gauge stays at about 11 o'clock.
- Heater works fine.
- Turn off car and fill radiator tank to minimum level. After several hours, when the car is cool, radiator tank is much lower.
- Run car again, and the level of fluid goes back up.

I figure the radiator is not clogged, as fluid runs through it after the t-stat opens. But could it be partially clogged? Or is the t-stat not opening soon enough?

Any ideas would be appreciated. Thanks.

Ben2

You may want to ask over at quattroworld, most of the more technical folks have moved that way.

grunlowen

The answer to my problem was getting a new coolant expansion tank.

If you have a similiar problem, where coolant is leaking out near the tank, look for leaks near the small top hose. The plastic underneath it has a tendency to crack. Easy to check, as you just need to pull off the top hose and see if the plastic beneath has any cracks (I had to disassemble the hose clamp with a small screwdriver, and then put a regular hose clamp back on it). FYI, tiny cracks might be normal. Mine had a bunch of tiny ones, and then a larger one that was clearly the problem. A temporary fix might be to put on a new hose clamp right up next to the base of the tank.

The expansion tank itself took me all of 15 min to replace. There are just 2 hoses and 1 sensor that pulls off. I didn't even drain it, just yanked it off. Spilled some coolant, but then just hosed it off. www.autohausaz.com sells the tank for $35 (and the cap for $2), so a pretty cheap repair.

Just Me

thanks for posting back. That's how we collect data points.