Tempature question

[Larry1]

My tempature gauge in truck says 195-200 degrees,but the Thermocap Radiator Cap says 170 which one do i believe.i am scarred to drive it now as i dont want to wreck engine.

[cleszkie]

I'd be more inclined to go by the temp gauge. The sending unit for it is most likely near the number 1 cylinder in the engine block. That is a much more important temperature reading than one taken at the radiator in the cap.

[GuyO]

Cleszkie is right. But they could both be accurate because the temp sending unit on the manifold is a "before" the cooling process reading and the cap is an "after" the cooling process reading. BTW 190 + or - is not a bad steady reading depending on engine load, cooling capicity and torque converter stall speeds or stop/start driving, etc. as long it your needle isn't going immediately higher on its way to boiling over. A strong water pump, proper fan with shroud, correctly installed thermostat, a multiple core radiator and an engine block that has been purged of air pockets are the normal keys to cooling issues. Good luck. G.

[GuyO]

A strange thing happened while pulling our travel trailer over the Snoqualmie pass. My temperature gauge actually "settled" down! I have a trans temp gauge I watch closely while pulling the camper. It reads consistently 160-180, but my temp guage from the intake mainfold sending unit always read about 30+ degrees hotter. After pulling the 40 mile pass for the first time on I-90, my engine temp guage and my trans temp guage now read the same! ?? Very strange, any ideas as to why?