Just stated over heating. I just noticed my top radiator hose sucks shut after it starts to cool down. I made sure the hose to the overflow bottle was clear but it just wont suck the water from it. When I take the cap off the top hose pops right back into shape. Time for a new cap and or thermostat?

 

I would do the cap first.  It sounds like it isn't releasing properly.  From the way you've described it the thermostat seems to be working, but it wouldn't hurt to do  both.  If you can get a discount at the local subie dealer, or order online, you can do both yourself for around $60 including coolant.

Make sure the hose in the overflow bottle is cut at a slant so that it doesn't just suction to the bottom. There was a TSB about this a while back.

 

O.

Try a new cap, and make sure the radiator is full. Burp the system to make sure there are no air pockets.

1. what vehicle?   is it the 99 forester mentioned in your sig?

2. are the fans coming on when it's running hot?

3. was the coolant low when it started overheating?

4.  any leaks?

5. have the headgaskets ever been replaced?

 

also check the radiator neck and make sure the sealing surface where the radiator cap seals against is smooth and not damaged.

Thanks for the help. The cap did the trick.  I did put a new head gasket on it when I had to replace some bent valves do to a broken timing belt. Beleve it of not the two fans have not worked in years.  Only slight overheating once in a blue moon if she was stuck in heave bumper to bumper traffic on a hot day. The fans will be  my next project so and advice on where to start looking would be greatly appreciated.

 

Thanks for the help

Chris