So I have an OBDII scanner and it can give me intake temp reading from the sensor, or so it says. Went for a cruise around the block in about 65 degree outside tepm. According to the scanner my intake temperature never really dropped below 108, that seems pretty damn high for it being 65 outside. Car has an AEM V2 CAI, so is the reading false or could sensor be reading data wrong or is my filter possibly too dirty?

 

Thats nothing mine would normaly get to like 150ish (or 60C+) on a normal day (my first AP1 - bluetooth OBD adapter/torque app)... now i have UKDM S2000 without OBD2 port and dont have these "problems" anymore

 

Your intake is perfectly fine, it is not affecting the temp readings.

I assume that you have an ap1 ?. If so that is pretty accurate with a cold air source. What the sensor is reading is the temp inside the intake manifold, not necessarily the incoming air temp from the intake pipe. The air temp reading is affected by all of the metal in the intake manifold where the sensor is located. I have a J's Racing cold air snorkel and I get pretty much the same temps as you in the same conditions - about 40 degrees over ambient in the best of conditions. But it can get much higher in stop and go traffic.

As soon as I open the throttle plate fully the temps drop quickly, as I close the throttle plate temps increase quickly. If I get out on the highway and drive at a decent speed the temp readings drop steadily the more I drive. The intake air that is entering the manifold is colder than what you are reading, but it is cooling off all of the metal of the manifold as it blows through towards the intake valve ports.

The intake air temp before the throttle body plate may be 70 degrees, but the intake manifold chamber may be 120+ degrees (with that huge amount of metal heatsink), so what you end up with is a reading of 108 degrees at the IAT sensor source ( just throwing out some estimates here for illustration purposes). On an ap1 you are getting a blended air temp reading.

They changed the location of the IAT sensor on the AP2's that would better reflect the actual air temp entering the front intake pipe rather than the temp measured at the rear of the intake system/manifold. The actual air temp entering the intake valve ports is going to be the same between the ap1 and ap2, it is just the readings on the scanner that would be different due to the location of the IAT sensor. I hope this makes sense.

 

You also have to remember the throttle body is heated with coolant to prevent throttle plate icing in the winter. There are threads floating around about blocking the coolant to the throttle body to reduce intake temps. Your present readings are correct for your intake as equipped.