coolant question

[kerv]

Is it normal after a little drive on a very hot day that after shutting the car off and it is cooling down, the coolant in the overflow resivor starts filling up past Maximum and keeps filling up until it almosts spills out? What causes the system to do this? It sounds like the coolant is almost bubbling out into the resivor like air is trapped in there or something.

Once the engine cools however, the level in the resivor goes way back down to the Min mark.

I have pushed on the upper radiator hose and it doesn't "spluge" or anything, so I don't think any air is there. The car hasn't been overheating either since I just had the thermostat and waterpump replaced.

Can someone fill me in on how this works and if I should be worried or not?

Thanks,

Kev

[sil80phobia]

it's normal for the level in the reservoir (on MOST cars) to rise when hot (metal expands) and to drop when cold (metal contracts).

Check
1. Oil cap. is there coolant in the oil? It will look a little milky.
2. Rad cap/overflow tank. Is there oil in the coolant?
3. When the engine is cold, take off the rad cap and start the motor. BLip the throttle. Does the coolant bubble or rise very quickly? Last car I had with a blown headgasket, doing this yielded a fountain of coolant shooting 6 inches out of the radiator.
4. Over a week, keep an eye on your coolant levels. It should normalize after a certain point where you aren't losing any coolant due to consumption/boilover, etc

[240sxconversion]

The whole thing with hitting gas with cap off makes old faithful is not true. I had a brand new 2002 chevy cav that did that, my 240 does it, and so does my crx, and all have new head gaskets

[kandyflip445]

The whole thing with hitting gas with cap off makes old faithful is not true. I had a brand new 2002 chevy cav that did that, my 240 does it, and so does my crx, and all have new head gaskets

:stupid:...................................

[ryan hagen]

mine did too, i think it has something to do with the water pump spinning faster when u rev it