So I installed a skunk2 IM and a new IACV. upon starting it didn't seem like it was cooling; getting hot in the engine but not on the gauge, no fan, hot upper rad hose, cooler lower rad hose. I've let it run like 20 min. with the rad. cap off to get the air out. I put in a brand new oem thermostat. I've also jumped the fan and that works. I am running out of options any suggestions?

 

You should be running it with the cap on air will vet through the overflow tank. Your system needs to build up pressure to a point as do most coolant systems wether you have a waterpump or not. As to your gauge not going up it sounds like a wiring problem or a bad temp sensor therefore the sensor is not putting out a reading for the gauge. Does your fan come on when letting sit at idle for large amounts of time?

 

yeah i've let it idle for at least 20 min. everything in the engine was getting pretty hot but the gauge was less than half way up.

 

late night bump

 

Are you boiling over into the reservoir or is it just getting hot to the touch?
remember motors get extremely hot wether coolant system ir running or not if you not boiling over and your temp gauge is operating you are fine my car gets to the very bottom of the coolant temp signal and stays there and that is it your car isnt overheating.
Since you said your lower hose was cool while others were hot check your thermostat suspend it in boiling water and see if it opens if it doesnt you arent getting enough flow and it needs to be replaced thus the cooler lowrer rad hose.