1998 Rodeo Keeps Overheating

My 98 V6 Rodeo recently started running hot. I can smell coolant (runs low after 3-4 days) but see no leaks. Took it to a radiator shop and paid $117 for the guy to tell me the radiator was fine, as well as the thermostat, water pump & pressure.
It did fine for about 4 days and then started overheating again. Once again, the reservoir was empty and radiator was low.
If there are no visible leaks, then where is the coolant going to and how do I fix it?

Thanks, Jeff

any water in the oil?

If you are loosing coolant & not seeing any leaks or coolant on the undercarriage/ground, you may have a head gasket issue. Coolant is getting into the combustion chamber & going out the exhaust & into the crank-case. How does the truck run? any CEL?
G/luck
Joel

If you are loosing coolant & not seeing any leaks or coolant on the undercarriage/ground, you may have a head gasket issue. Coolant is getting into the combustion chamber & going out the exhaust & into the crank-case. How does the truck run? any CEL?
G/luck
Joel

Truck seems to run fine and no CEL.
Jeff

I would take it somewhere and have them do a cylinder leakage test. Chances are you have it leaking into the engine and that would remove all doubt. Pull the spark plugs off, you should also see evidence of coolant on the spark plugs.

Could be cracked head. The 98 and 99s had a problem with the heads cracking between the sparkplug holes. The leak is on the top side of the head and will show up as light tan on the under side of the oil cap or valve cover. It will not show in oil. Also check the spark plug tubes for signs of antifreeze.

-pressure testing heads wont do any good either because the cracks wont show untill the heads are hot when they aer cold cracks can seal enough to not leak (aluminum)

I took out only one spark plug and there were no signs of coolant on the plug. Is it necessary to check all 6 plugs?
Jeff

I took out only one spark plug and there were no signs of coolant on the plug. Is it necessary to check all 6 plugs?
Jeff

If you are looking for a cracked head or bad head gasket, I would remove and inspect all 6 spark plugs.

Since you are smelling coolant, Have you checked your interior carpet and/or ductwork to see if it is damp? Do you see any steam when running the heater on defrost?

If so, you have a leaky heater core.

Just a thought on my part, it may turn out to be a cracked head or bad head gasket after all.

I hope that isn't the problem with your Rodeo.

Dale