Engine temp on my car stays around 108 even on highway and cool outside temp.It never goes down,fans are working.It developped this problem suddenly.Checked everything...(almost...)
I also suspect my rad to be the problem of overheating but...When I shut the engine off and the fans keep on turning for 20 minutes ( as they are supposed to do when the coolant temp is higher than 100-105 to avoid heat soak)the coolant temp goes down to around 90 in a matter of 30 seconds!!! Is the rad working or not??? Is it possible it is partially blocked/clogged so it is sufficient for the recirculating pump cycle (engine off, less volume of coolant passing through/required) and does not have enough efficiency to cool the engine when running???
Could it be a water pump problem? What are the signs for water pump failure?
Also,since the temp gauge ( coolant)starts to climb only after 20 minutes of driving, is it possible that the oil coolers are not working properly, since I think the oil normally takes more time to climb in temperature(??).The oil temp light does not come on...
Thermostat seems OK. Coolant feed hose to rad is really hot.
The thing is I do not want to change the rad ($$) and find out it was not the problem...