Hello everyone, I'm new here.

I have a 2000 F150 with a 4.2 v6, 5spd that has 128000 miles. For a while, I've been getting the red oil temp light in the left side of the gauge cluster shortly after start up. That has progressed to getting the red oil temp light and a temp guage that pegs HOT after about 15 minutes of driving. These indications come and go randomly, and the truck is NOT overheating.

On two occasions, I got the red oil temp light, temp gauge pegged hot, and the truck dropped cylinders and gave me the Check Engine Light. When I put the code reader on it it was P1299 (Cylinder Head Overtemp Protection, etc). Through this forum, I found that my Cylinder Head Temp Sensor was on the aft end of the driver side head, so I changed that. It didn't fix the problem.

When I turn the truck off, then re-start it, the red oil temp light goes away, and the temp gauge goes back to normal. If it drops cylinders, the CEL stays on until I clear it with the code reader, but sometimes it just gives the oil temp light + H temp guage, so when I turn off/re-start, everything is fine again until the stray electrons start acting up.

I don't know where to hop. Is there another sensor that could be at fault? Thermostat? New Radiator? Thanks in advance for your help, guys.