Hopefully someone on here can help me out with this, cause I'm really starting to wonder wtf is up with my car.

I cant stop my coolant overflow bottle from filling up (until it eventually gets too full and spills). At first I thought "damn, coolant seal" but the slow rate at which it's filling is confusing me. If I top off the filler, ast and fill the overflow to F while the car is cold, after a day of driving the overflow will read about 2-3 notches above full and the filler level will be down about that same amount. Another day and the overflow will be another 2-3 notches higher. By the third day I'm usually syphoning coolant out of the overflow and getting a low coolant light on cold starts .

Appart from this, the engine runs fine. Normal temps and all. Could this be something as simple as a bad rad (ast) cap? (my next step). Any ideas?

 

bas thermostat or bad water pump?

danny

 

Bad radiator cap?

 

Bump... anyone else had this problem??

 

Get a new radiator cap and AST cap. It might be those.
If not, it could be the air in your system or coolant seals.

 

Thing is, I'm not actually loosing coolant... it just seems to all be slowly heading into my overflow bottle. I've never seen the bottle level actually go down.

 

There could be a leak in the coolant system somewhere (bad caps, cracked hoses etc). The symptoms your discribing is the same for an external leak. Like someone suggested, pressure test it and try to find the leak.

 

The pressure test is good advice. NAPA sells a kit (or you can rent one).

A bad coolant seal can send pressurized gas into the coolant system pushing coolant from the system into the overflow. It certainly could be this. Have you ever overheated?

But...

It could simply be a bad cap, bad gasket, bad hose, leaky AST, etc. The coolant gets hot, some gets sent to the overflow relieving pressure (normal), then when the system cools down, there isn't enough vacuum to pull it back in, as some pressure was lost through the leak.

If you don't have any smoke at startup, then the coolant probably isn't getting sucked back into the combustion chamber. Besides, it sounds like all of the coolant is accounted for in the overflow. Don't run out and rebuild just yet.

Anybody know where RXcetera can go for a good map of the coolant system? This will help finding all the hoses. These are them, but no diagram...

http://www.mazdatrix.com/bhose3.htm

Pay close attention to "Tank to overflow" (P/N 15-380C-N3A1)

Good luck.

 

Well, it turned out to be a bad rad (ast) cap. The lower gasket on the original one had swollen to the point of inhibiting the proper function of the cap. With the new cap, my engine runs cooler and under less pressure (allthough its the same .9 cap).

Thanks alot for the help guys . I cringe to think that maybe someone out there had this same problem and invested in a rebuilt to fix it .