blacker

I own a 1989 Z51 car. It typically runs no hotter than 212 degrees until I am pulling into the garage. When I do the temp will run up to 225 degrees and the secondary fan will turn on. Today it did not. The motor had reached 234 degrees by the time I shut off the car. I let it sit for a few minutes and cranked it to see if the fans would come on. The primary engaged as soon as I cranked the car so I know it's in working order. Should I be concerned and if so what should I check?

billschroeder5842

Concerned, yes, freaking no...

Start by checking all the connection for dirt and corrosion.

I'm not sure on an '89 but later models have two relays. If you have two relays, you need to check the AUX. Also, on later models, the AUX comes on at 238. Not sure why yours comes on earlier, but the engine temp on the dash and the engine temp for the fans are two separate circuits.

Test your system by turning on the AC--- everything should fire up at that point

c4cruiser

If the observed temp is accurate, I would start by looking for dirt and debris in front of the A/C condensor and also between the condensor and radiator. Getting junk in there reduces airflow and is probably the leading cause of higher than normal coolant temps.

You can use a hose and nozzle from the fan side to rinse out any garbage. A shop vacuum will also remove loose dirt. Also check the condition of the lower air dam; it's necessary to force air from under the front of the car so it passes thru the condensor and radiator.

Also, how old are the upper and lower radiator hoses? It's possible that the lower hose is collapsing which reduces coolant flow. Remove the radiator cap (on a cold engine) and look for any signs of corrosion that may be reducing the coolant flow thru the tubes.