I'm pulling my hair out. I don't have much , so help? I have a 1969 Mustang Coupe with a 351W (not original motor). 2 weeks ago after I started it and the idle kicked down, I noticed the temperature gauge went right to the H. However, no red light came on to tell me it was overheating so I figure I'll drive around the block and see what happens. When I got to the end of the street, the temperature gauge is in the middle. Huh, I ask myself . So I drove somemore. Now it's moving to the H again but not going over. It just stays there. I change the thermostat, check the fluid, and check the engine over for leaks. Everything seems to be ok. Today I start it. and within 3 minutes ( I timed it) it at the H again! I took it out for a spin and everything seems to be ok, although the gauge still says H. So here's my question, is the car really overheating? Could the sending unit or the gauge itself be faulty? Help!

 

i don't think any car is going to overheat in 3 mins. unless maybe you have no oil in it and your rings are messed up to begin with... but still 3 mins. i doubt it. yeah check your sending unit. don;t keep driving it though just in case. maybe get a heat gun and check it out that way.

 

sending unit is bad trust me!!!