Overheating I think

[MaxT]

I own a 2003 2.3 Ranger. Runs great, only has 42000 miles. All gauges normal. I hooked up my scan gauge and my water temperature is at 260.

It has the yellow coolant and it is just below the minimum mark. The upper radiator hose and the heater hoses get hot which the service manual states means the thermostat is working. The lower radiator hose stays cool. With the 2.3 motors having the thermostat at the end of the lower radiator hose, I thought it would be a bad thermostat.

Any ideas or suggestions?

Max

[Simple_serf]

Hmm...what are you using for a "scan guage"?

260 Is WAY too hot, in fact it's hot enough to make me wonder if the scan tool or a sensor is screwy.

[MaxT]

It's name is "Scan Gauge". It plugs into the data port. I checked the temperature this AM on the scan gauge and it read 59 degrees at startup with an outside temperature of 49 degrees, then quickly rises.

It changes too fast for water temperature. I've read my service manual and found that the 2.3 has a cylinder head temperature sensor also. I'm thinking that this is the temperature the scan gauge is reading since it does rise so quickly. I can see the cylinder head temperature rising quickly with the engine running. Water temperature usually rises slower, especially when cold outside.

The truck does not boil over or show any other overheating signs other than the scan gauge reading of 260. It also stays between 250-260 and doesn't get any hotter like it is being regulated instead of something stuck. It's a mystery unless it is the cylinder head temp I'm reading.

Thanks for any insights.

Max

[Wicked_Sludge]

your computer will actually trip a CEL if anything screwy is happening with the engines temperature. if there are no codes (and the stock gauge shows OK), i wouldnt worry about it

[MaxT]

Good point, I think the gauge is reading cylinder head temperature instead of water temperaure because it runs great and does not overheat.

[addiman09]

its probably just wired in wrong, check your connections and then check where every wire runs, you could of mixed up the wires and tapped into the wrong one.

[MaxT]

Thanks for the help and ideas. I put a gage in the upper radiator hose with a kit from Summit Racing and the temperature runs fine. I did not tap into any wires as I'm using a Scan Gauge II plugged into the computer port so it reads whatever is factory wired into that port.

Max

[Kaz]

good to know, i was just about to replace my water pump and t-stat cause i though mine was running to hot, cause its doing the same thing as yours. thanks.