the engines is ? what stock/high mile to full blown street racerThe car has "overheated" (on gauge) on the highway and on sidestreets though has only boiled the coolant when I push the motor hard for about 10 miles or drive it more than about 20 miles. I know there is a problem but I do want to have an accurate reading to help the diagnosis. As far as the motor goes. the only things I can think of would be a blockage in the block or a problem with the heads or gaskets.
The t-stat has been pulled (after trying two and testing both), the lower hose is new and does have a spring in it to prevent collapsing. The radiator is a year old and does have a shroud on it.I would try venting the cooling system you may have some traped air. What temp is your stat? Lower hose could be colapsing. Do you have a fan shroud? How old is the radiator?
get a high quality mechanical gageSorry the motor is a stock '66 289 with 16x,xxx miles. I believe it was overhauled about 20,000 miles ago (before I got it). It has been indicating a hot temperature since I installed the temp gauge in April. When I checked the temp at the intake manifold with my infrared it shows about 20-25 degrees cooler than the gauge is indicating.
I checked the gun on a glass of ice water and it read 32.6 degrees. That's how we make sure our thermometers are accurate at the restaurant so I don't think it would be any different with this device. Looks like I'm going to get a new gauge.get a high quality mechanical gage
25 degrees difference , one of the instruments is off