coachmendave

My 98 chevy van with 191000 miles and a 350ci engine continues to lose lots of coolant. The radiator cap remains cold while the hoses get hot. The heater is normal I cant find a leak even though there is no coolant in the oil. Does anyone have any ideas of where to begin the search. That doghouse is a bear to remove and time consuming. The overflow resevoir and hoses are dry. Any ideas are greatly appreciated. Thanks for any help!

canucklehead

If you have no visible external leak, but are losing coolant, then it could be an internal issue. The coolant could be boiling out, a bad rad cap may be letting coolant out below the pressure its supposed to keep it at. You could have a bad head gasket and cylinder pressure is getting into the water jacket. You can use block test fluid to test to see if exhaust or combustion gasses are getting into the coolant. You could have air in the system. Have to topped it up, and then run it with the cap off till it reaches operating temp? Leave the cap off until the upper hose is hot, and you are getting hot air from the heater.

Hope those ideas help

SnlpeR

could be the infamous intake manifold gasket leak
do you get abnormal white smoke on the first startup of the day?

JIMMYDRIVER1

if you've ever let it overheat it might have a cracked head.

solwav

A bad head gasket could be the cause a slight leak could slowly draw coolant into the engine. Your exhaust would be notably white it the head gasket is bad.