96 Legacy GT. EJ25 DOHC (This is the same car as I posted about it burning oil at about 1 quart every 150 or so miles. )

 

My girlfriend has been driving the car and I've been keeping track of the oil level every night, and at the same time checking the coolant level since I had also just done the head gaskets and swap in the motor. Tonight I went out to check it and the fluuid in the resevoir was way up and the BOTH radiator hoses were sucked shut! Pulled the radiator cap off and heard it suck in air and then I could reform the hoses. Like I said, the GF has been driving it and she said she never saw the temp gauge move, but even if it did move I don't think she would have noticed(you know, watching that road thing a lot of us don't look at those gauges much).

 

So, What in the world could cause this? Right now I'm thinking it's a major blown head gasket that put a lot pressure in the cooling system, forcing the coolant out, and when the system cooled itsucked the hoses shut?

 

HELP

 

Keith

I would hazzard a guess and say start with a new radiator cap. It sounds like the mechanism may be stuck.

Hopefully it's just the rad cap, that would be my vote to try first also.

 

We had that happen on our TS when it was pretty new, I only remember the top hose sucking in, but it was the rad cap replacement that fixed it.

 

Steve

Another vote for cap.

Caps are cheap..... start there.

I'll give the cap a try, right now I'm worried about what damage could have been done since I have no idea when this happened.

 

Keith

The small silver piece the size of a dime on the radiator cap is stuck to the big rubber gasket. Just pick it loose with your fingernail and it will be fine. The big spring in the cap is the overpressure relief, and the small silver disc in the middle is the underpressure relief. What happens is water expands on heatup and is vented to the overflow. On cooldown, a vacuum forms in the system and the water is supposed to siphon back into the radiator to keep it full. The hoses collapse due to atmospheric pressure and will be fine unless it's been like this for a very long time.

Yes sir, start with a new rad cap. The explanation above sums of the function nicely :-)

Yes sir, start with a new rad cap. The explanation above sums of the function nicely :-)

 

Yeah, it all seems to make sense. So then this probably all occured after it was shut off, and as long is I caught it after it first did it I should be fine. What would happen if the cap failed, the hoses got sucked shut, and I didn't know. What would happen if I would start it up and drive it? Any ideas?

Pressure would build back up and the hoses will expand. If it loses coolant it can't get it back from the expansion tank so eventually it is a problem.

re; the little button in the center: Sometimes it just gets gunked-up and stuck.

 

If that's the case just clean the entire cap really well with detergent and a stiff brush. Just be sure to rinse it completely afterwards.

Well, I know everybody wants to be as cheap as possible, but instead of using another cap off another radiator, or cleaning the existing one, I spent the $6 and bought a new one. Installed it, topped off the radiator and took it for a drive. Temp gauge never went above the mid point, and so far everything seems ok. Just got back from the drive 15 minutes ago, so in another 45 I'll go check and seewhat the hoses look like.

 

Keith

Shure enough, the hoses didn't collapse again and the car drove on another 15min trip just fine. Radiator cap was it.

 

Thanks for all the input!

"I love it when a plan comes together!"