Coolant overflow problem???

[Turbo Juice]

my car is constanly overflowing coolant. it is real obvious in the winter because my heat wont work at idle. there is no oil in the coolant and no milkshake in the oil. The coolant ends up in the overflow bottle so it is not being burned off. also it does not get sucked back in from the overflow bottle.
i can do city driving fine for a few weeks, but if i drive on the highway it will overflow worse causing the car to overheat because of lack of coolant.
it overheats only because the coolant is low though.

i have a greddy rad cap, just had the motor redone with arp studs and mls gasket, new autozone 170 thermostat, non-watercooled turbo, not so old water pump.

i am really aggrevated and cant figure out why it is always running low on coolant.

 

[xveganxcowboyx]

What is your coolant to water ratio? How does the coolant look? Can you hear the coolant boiling when it's over-flowing?

I would recomend changing back to the stock thermostat.

 

[silver eclipse]

Did youn post this a bit ago?

Its sounds like the radiator cap. Try putting a stock one on.

 

[Turbo Juice]

ratio us 50/50. there is no boiling sound, but the water is not boiling over. it is overflowing for another reason.
the temps are also under 205 at the most. the car only gets hot when the coolant is already out of it.

 

[steve]

Have both the cap and the system pressure tested.

Steve

 

[silver eclipse]

Hows it working out? Did you get it checked?
-Chad

 

[Turbo Juice]

i havent really had time to do much.
it is still doing it though. my heat is real shitty and it is freezing where i live. i plan on getting an oem rad cap and thermostat.
and i am trying to score a pressure tester on ebay.

 

[jking29]

A cracked head can cause these symptoms also. My turbo coupe had the exact same symptoms with no oil in the coolant and no coolant in the oil. It was fine around town, albeit with no heat, but when it hit the highway it would blow all the coolant out of the overflow and overheat. When I pulled the head I found a crack in the head that ran from the edge of the combustion chamber to a coolant port. On the highway the crack would open up enough to allow combustion pressure to blow into the water jacket, pressurizing the coolant system and pushing coolant out of the overflow until it overheated from the loss of coolant.

 

[The Butcher]

Sounds like jking29 is on to something here!