Im having a problem with my 10th AE when im driving uphill on the freeway. The temp gauge will go about 2/3's to 3/4's up between the C and H. The car has a new thermostat, but one thing it doesnt have is the plastic under tray. The car does have the metal undertray for aero dynamics, but i currently dont have the lower most plastic thing on. Is it completely necessary? Could not having it cause this to happen? Do you guys think i hurt the car by getting it that hot? Thanks

 

It is on there for a reason, definately put one on.

 

yah you should keep those plastics, undertray is used to cool ur rad and oil cooler and things. plastics on top in front of the rad direct air to intake and rad (i think) etc, either you replace with better one or keep oem ones

 

If that doesn't solve the problem, I would look into your AFR. Sounds like you might be lean.

 

Its really strange because its only if im going over 65mph. If im going slower than that it has no problem. If must be some strange aerodynamic phenomenon...

 

Its the under tray. The radiator is mounted at an angle so at lower speeds the fan is sucking air thru it. But at higher speeds the air goes under it instead of being forced thru it without the under tray.

 

You need to go ahead and install your undertray.

 

Okay, i reinstalled it, and it seems to do better, but it will still heat up, just not as much. Do you think it could also be caused by having the air pump eliminated and only running 1 belt on the alternator?

 

The water pump will slip without the airpump. Either get a dual alternator belt or search the forum for "yoohoo belt" and run that.