1999 rodeo overheating maybe thermastat - 1998 Isuzu Rodeo

No thermastat or thermastat clogged

Hello. A common mistakes when doing repairs to the cooling system is not correctly bleeding all air out of the system, which in turn will still cause your vehicle to overheat.

1.Make sure cooling system is purged of all air.

2.check all hoses for holes (assuming you didn't use new hose.

first post is a viable option but i would do some diagnostic work first , check the OBDII codes as may be a sensor/switch that has overheated or got fried , check cylinder compressions to check for head gasket etc

With a over heating problem the first place you always check is the thermastat.Thermastats ALWAYS go.
In fact every two years I change the thermastat wether or not it needs it just to be safe than sorry,I live in a snow belt and nothing worst than having no heat in the winter.
Something else you might keep in mind, over heating can do allot of damage most people don't consider, the transmission lines are connected to the radiator which cool the transmission

when changing the thermastat was there oil there also? Sounds like you have a blown head gasket, sorry

If you aren't loosing any antifreeze, you might check to see if the coolant fan on the radiator is coming on. If the thermastat is sticking your radiator hose will be solid to even swellen sometimes. Of course not to mention that if a radiator is over 5 years old, it could be bad, so you may need some things checked futher.

Is there a bleeder valve on the thermastat housing or the water pump. if not check to see if your loosing coolant and the oil level

Most likely have a bad intake gasket, or clogged radiator. make sure your fans are coming on also.

fuel filter maybe?

it sounds like you need a new Radiator or you are leaking coolant and thats why its overheating, check your rad fins and then your coolant level