Just purchased a 1996 GT with 4.6 engine. Using Mobil 1 and Fram filter and just had cooling system flushed. Replaced the thermostat with OEM due to guage reading over the mid line and hot. Now the oil pressure guage and water temp guage are fluctuating. The water temp goes almost to the red line and then returns to right above mid range within a couple of minutes. I turned the heater on and it had no affect on the temp reading. The oil guage fluctuates, regardless of rpm, from one quarter to middle to just over mid point. The fluid levels are good. Does anyone have a suggestion to correct. The mileage is 72,000 and runs strong. Thanks

 

The water guage on the Mustangs are not good at all mine and others do that, best to get a after market one to get a good water temp. As for the oil guage mine was replaced at the dealer and it only moves when I start it up, so again replace it with a after market guage. Just saying.

Or if you can hook it up to a computer to see if the guages are right or not.

 

could that happen on a ranger?

 

I haven't heard of a Ranger with that problem.

 

THANK YOU. THE TEMP COMING OUT OF THE RADIATOR IS 160 DEGREES AND OUT OF THE BLOCK AT 202. THIS SEEMS GOOD ACCORDING TO EVERYTHING I HAVE READ. I WILL REPLACE THE GUAGE.

 

Hope it works out for you.