Fan blows cool and car starts to overheat...

[MAB]

On my way to work this morning and all the sudden the fan starts blowing cold air..three minutes later the needle starts to move to overheating range...shut car off...restarted and fan started blowing warm air again..ran fine for 5-10 minutes and did the same thing...fan air went cold and car started to overheat ?

got to work..parked car..Opened hood and didnt notice anyting unusual...car has been sitting for a week as I have been out of town...no puddles on my garage floor though ? will check coolant level this afternoon, however I dont believe that is the issue ?

Any ideas ?

thanks...

Matt B.
Northern VA...

[MAB]

last summer....no issues since then...

[william540i]

Did you get any indicators saying "check coolant level"?! If not, you may want to look into why... The cool or cold air coming from the vents when it should be hot indicates there isn't enough coolant flowing thru the heater core... Which also means the coolant level is low enough to have air pockets in the system... When these air pockets hit the water pump, you get cold air in the car and now coolant flowing to cool the motor... Until the coolant reaches the pump, the coolant in the block sits and the temp rises... The easiest way to determine if this is the case, check the top radiator hose for pressure and temp... Positive pressure (solid feel) and hot is good... Negative pressure (squeezes) and warm or cool is not good (unless just started and not up to normal operating temp yet)...

Let us know...

Cheers!!

[edjack]

If it just started doing this, you may have a leak that is admitting air.