Sic6stang

Hi all, i'm in need of some assistance. my car has been running hot ever since i had a little issue at the track. i Had just bought my 96 mustang gt, and wanted to see what it ran so i took it down the track, earlier in the week i installed my stereo and amp, but also had noticed a sound which seemed to be coming from the alternator which led me to believe my alt was about to go. so i took it to the track and on a pass my battery light came on so i thought the alt went and i finished the run wot, turns out my belt tensioner snapped the arm off and threw the belt of course and the car overheated enough to boil over from the coolant overflow tank. so i replaced the tensioner and belt and ever since it has been running hot. it gets up to the L in normal on the temp gauge before cooling back to the M. im not noticing any loss of coolant if so it is very little. i dont constantly have white smoke from the tail pipe but it will put out a little puff occasionally. i replaced the thermostat with a fail safe one and put on a new radiator cap. im not noticing any moisture on the passenger floorboard under the heater core, nor do i see any signs of coolant mixing with my oil or vice versa. i have also noticed that the coolant will be low when i start the car but after 3 seconds it is back up to the proper level. and my fan doesnt seem to be coming on at the low temp setting. it doesn't turn on until i get up to the a-l range on the temperature gauge. i was hopeing the gauge was messed up so i hooked my tuner up to see the data logging and the coolant temps are actually reaching 212-213 degrees so there definitely is an issue but i can't figure it out. it does however appear that i have a small crack in my intake manifold right above the front drivers side injector. could that cause the running warm? any suggestions would be appreciated

Z28KLR

Crack in the manifold is key here.

Also, when you replaced the t-stat did you burp the system to relieve it of any air pockets (which usually occur in the vicinity of the t-stat housing and inhibit cooling system performance)? If not, run the engine up to operating temp with the coolant reservoir cap off, and when the t-stat opens up grab the upper hose and squeeze it a few times to displace any air in the system.

If you did not do that procedure, that is also a likely cause as to why there's a crack in the intake manifold. The good news here is, when you go to replace it you can use a PI manifold and get a nice little bump in performance out of the swap.

Sic6stang

okay, I did burp the system after installing the thermostat but not right away, it was a couple days later when i was reading about air pockets in these motors. and i was reading about doing the pi intake swap and it sounds pretty easy just a dab of rtv around one of the ports otherwise straight replacement with pi gaskets right?

Z28KLR

^ Yup, pretty much plug n' play. Hit up the search feature here, there should be countless threads detailing the swap.

Sic6stang

Did a few checks and i don't seem to have any cracks in the intake manifold and not seeing any leaks. Also did a bubble test so I'm not getting air into the system so I'm thinking its just the fan not coming on at the lower temp. Is it normally replacement of the fan or is it normally a sensor issue?