1999 S80 T6

After the car is driven and up to full temp, if I park it and shut it off coolant will push out of the reservoir overflow at an alarming rate. I have to fill it up almost daily. Is this a thermostat problem? I know that many vehicles with main fill caps that are busted will push coolant out constantly, but I can't seem to find a fill cap anywhere besides the reservoir. Any thoughts?

Thanks,
Chris

:blush: Are you sure your not overfilling the reservoir.? If filled to the very top then the fluid has no place to go but out the overflow tube....Thats the reason for the fill line on the reservoir....On mine its about half way up on the container itself.

Yeah, the t6 has a warning light that comes on and say "coolant low, stop engine" if you are even a touch low. If that light's not on you're probably overfilling the tank. The line on my 02 t6 is also about 1 1/2'"'s from the top of the tank.

It is giving me the "Coolant Level Lo" warning. It is really annoying because it keeps pissing out coolant and I have to refill it every few days or the car gets hot in the summer heat. Any ideas? I am not thinking headgasket because it will go indefinitely without overheating and usually a headgasket problem will cause the car to overheat any time it is driven. Water Pump? Thermostat?

Thanks in advance,
Chris

Iam having the same problem in my S80. I was thinking that it might be the thermostat not allowing the coolant to circulate threw the engine. When you find out the problem please post, I'll do the same

Thanks,
Shawn

Mine was not this bad but I was always having to fill my resevoir. Then it competely overflowed one evening at home. My resevoir had a crack in it causing this leak. You might want to pull the resevoir and give it a check.

I have the same problem. After a week of trying to figure out where it was coming from I noticed it dripping from the overflow cap. It was bubbling and leaking out. I just bought another radiator cap to see if this is the problem. I drove from the parts store to work and it didn't leak. The true test will be on the way home because it always leaks by the time I get home. I will update this tomorrow.

Overflow cap # 10244 mfr: Stant
NAPA p/n: BK7031396

Dearship wanted $32 for it. Napa was $11.55

+1. The cap has a spring-loaded relief valve in it which may fail after a while. If that doesn't cure it, I'd check the radiator for obstructions, make sure the fan was coming on, then change the thermostat.

The reservoir cap is the only cap on the system. It contains the relief valve.

Well I confirmed it was this cap. I don't have anymore fluid coming out of the tank. I guess the small crack on the inside of the cap was the problem.