the check engine light came on yesterday while wife was driving. car seemed to drive fine to her. this morning i started it and looked under the hood. the hose connecting the radiator to the block was flat while idling. so there is some kind of abnormal suction going on...? thought i would check here first before i risk driving it to get scanned.

thanks for any help,
shea

1998 accord coupe 165k miles automatic

 

Bad radiator cap?

The cap controls the ability to suck water back in as the engine cools down. I bet the hose collapses when it cools down & fills back up when the engine gets hot? Look at the smallest little disk on the underside of the cap - that's supposed to open up with very little vacuum.

Or maybe the hose to the reservoir is plugged?