kainZ

It didn't overheat (temp wise), but it pissed coolant out of the resivoir...

Does this mean that I overfilled it?

Or did it somehow boil?

phinger23

you over filled it and it overflowed out the top

IDAREU

either overfilled or the cap has gone bad

mitchntx

My rad is filled to the neck and doesn't move any fluid to the tank until it gets to 225 or more ...

I think you saw my Radiator cap tech thread. I would bet your cap is toast.

http://web.camaross.com/forums/showthread.php?p=3063891

kainZ

Well... It DID get past 225... probably 230 or so..

But yeah, its a new autozone cap.. so it may be a crap cap.. I'm not sure.

I don't have the air diffuser thing (that goes beneath the front facia) on the car right now, so I think the only thing cooling the radiator is the fans.. which don't come on until like 223 or something..

It shouldn't be pissing coolant until it hits like 250 if the system isn't overfilled though, right?

I've been bleeding the air out every time I drive it (before I start and after I shut it off). It pissed coolant once again yesterday, then after that, it didn't **** any on the two other trips, but it got hot, and blew a LOT of steam out (for like a minute or more each time I opened the bleeder screws).

Could I have that much air in the system, or is my water boiling off into steam???

I'm still wondering if it's a bad cap, overfilled, or because of the missing air deflector, or a combination of the three.. I'm going to wire up a manual fan switch today (which will force the fans to stay on while the car is running), and see if that helps at all..

Any suggestions are welcome!

EDIT: I should note that the reserve tank seemed a bit high the first couple times it pissed coolant, and then I checked it after the last time it pissed some out, and it was dead on where it should be.. so part of me is leaning twards the conclusion that it was pissing because it was overfilled, and that it's staying above 225 because the only thing cooling the radiator is the fans.. but that still doesn't explain all the steam coming out the bleeders..

mitchntx

Rule of thumb is 3* for ever PSI your cap is.

So, if your boiling point is 230* (with coolant mix) and your cap is a stock 18 lb cap, you coolant shouldn't boil till it reaches 284*

Air will compress, but water won't. So as your coolant heats up, it expands. If there is an air void in the radiator, it will use up that room, compressing the air. Once the air pressure reaches 18lbs (the stock cap psi rating), it will lift and coolant will "squirt out" with the air pressure. Once the pressure drops below 18psi, the cap will re-seat. And the system will cycle like that, rapidly.

With tehsystem solid (no air), the water will push the cap open and force coolant into the overflow tank. Once the system begins to cool, it will pull the water back into the radiator.

After what I've been through, I would take my current radiator cap to any radiator shop and ask them to pressure test it. If it's nowhere near rated pressure, then I would go to a GM dealer and get a new TVS brand cap (mine cost $7) ... go have it tested to make sure and see what happens ....

LT1_SS

Go get yourself a GM cap from your GM dealer/gmpartsdirect.com or where you can get a GM part. Autozone, O'Reilly, NAPA, Advanced Auto, none of the caps they gave me worked. I got the GM one. Problem solved. You will pay more but it will fix your problem. I bought 5 different caps from 4 different places before I went to the dealer.

1. Get new GM cap
2. Refill (if necessary)
3. Re-bleed
4. Your done

Good Luck!

phinger23

you dont need to buy a switch to jump your fans. just need a wire on relay fan # 3 i think, and jump it spots 1 and 5 if im not mistaken. thats what i did, car stayed at 180 pretty solid...and thats with only 1 fan working.

kainZ

By switch, I meant a $1.50 walmart toggle switch. I'd rather not have to pull a wire out and put it back in when I want to switch between fans-always-on-while-engine-is-running-mode and ecu-controlled-fans mode


EDIT:

By the fans stayed at 180 solid, did you mean with the fan running, without the air diffuser hooked up?

Andrew04ME

I never have solved this problem on my bird. I replaced the cap with one from Autozone. Didn't fix the coolant dump. I find it interesting that the GM cap fixed this problem on some of your cars. Maybe thats the issue. All along i assumed i had a blown head gasket or crappy radiator. Kain, i can relate to all of your issues however. It will be interesting to see if the GM cap fixes your problem, be sure to keep us posted.

phinger23

ECU fan control is retarded. 226/235 is way too high. mine runs when the key is on.
my car drives at right below the 180 mark, and in city traffic runs at 180-185 (just a hair over the 180 mark) with only one fan running constantly. i have a 180 Tstat

kainZ

I'm still wondering.. do you have the air diffuser under the front facia on your car? I'm missing mine ATM, and I'll be happy if the fans alone will be able to keep my car at 180 until I get it put back on (so I can take a trip longer than 5 miles, lol)!

kainZ

It's officially been boiling over now.. I've never seen it boil like this before. The temperature staying around 2/3 from the top of the gauge (not in red), but it won't stop boiling. I'm going to do the fan thing as soon as I actually get the time, and also get the GM rad cap...

LT1_SS

The fan will not kick on if your system is not properly pressurized (which with that rad cap it is not) Don't worry about the fan thing right now. Go to the dealer and get the new GM cap, refill and rebleed the system. Also might want to check all of your hoses to make sure there are no leaks in them.

mitchntx

Brother, invest $7 for a new cap before you blow a head gasket ...