Car is having a few issues. Need some help diagnosing them.

[mncontour]

We have a '99 ford contour 2.0l 4cyl. with a 5spd and 184,000 miles on it. It has a few issues that I need to attend to. The car needs spark plugs and wires really bad, it has a really bad misfire right now. But here are the other two issues that need attention:

1. If the car idles sitting still or its being driven around neighborhoods or whatever, the heat gauge reads in the normal range. But if its on a freeway the heat gauge reads cold.
Im thinking the thermostat is bad.
Any other idea as to what could cause this issue?

2. If the clutch is engaged or if the car is in neutral the engine revs climb pretty high (I don't know how high because the car doesn't have a tach). And I have to feather the clutch and sometimes almost stall the car to get the revs down.
Could a bad IAC or TPS cause this?
Could the two issues be related by any chance?

Thank you in advance for any help.

 

[B3NN3TT]

If the clutch is engaged or if the car is in neutral the engine revs climb pretty high (I don't know how high because the car doesn't have a tach). And I have to feather the clutch and sometimes almost stall the car to get the revs down.
Could a bad IAC or TPS cause this?

Bad IAC or a bad vacuum leak is about all it could be. Maybe some grit or sludge in the throttle body that won't let it close all the way.

Vacuum leaks can also cause misfires.

 

[mncontour]

I haven't driven our Contour since it start reving up on its own. Someone told me to spray carb clean to test for a vacuum leak. When I spray carb cleaner around the throttle body base where it mounts to the intake, the engine revs jumped up a little and stayed there but would come down after a little bit. Is there a gasket between the TB and intake that could go bad?

 

[dennyb]

Rockauto 2.0L throttle body gasket Fel-pro 61105 victor reinz G31608