another SHO running too hot

[Venom SHO s7]

about 1 month ago my 89 sho started to run at about 3/4 of the way up on the temp gauge.. and dayslater it started running pretty close to the red.. so i replaced the thermostat and it started running fine.. never more than 1/2 way up on the gauge. after that.. i happened to run across an SVT contour who wanted to race.. so i did.. after beating him 3 times i noticed the needle was up a little higher which i though was cuz of the race.. but now the car is running hot again.. i then changed the temp sending unit and its still running hot after just a few minutes of driving.. i dont see the radiator leaking and the thermostat is only weeks old.. i noticed several others SHOs that had the same problem so i thought id ask too any suggestions would help

 

[SolidState]

replacing the rad cap is an easy thing.

But be forewarned that if you are running your original waterpump, there is a chance a new rad cap will cause it to leak.

 

[Off Road SHO]

Like Teg said, check the pressure holding capabilities of the cap and the cooling system.

Mike (Gloffer) brought his 93 MTX over yesterday saying the needle was up into the red but it didn't boil over or smell hot. Put the infrared thermometer to it and everything was just fine; 179 degrees on the thermostat housing and radiator. Probably the sending unit for the gauge, the one with the single wire going to it.

Tom

 

[Venom SHO s7]

hmmm i just realized something new.. tell me if it could be a cause... the thermostat i got i bought from NAPA. and i just heard that since it is not the one with the jiggle valve...it can cause the car to run hotter. if this is the case.. does anyone know of another thermostat besides the motorcraft one that has the jiggle valve?