I just bought hp tuners and was just looking around at some of the gauges and I noticed my iat's were red and at 145 degrees. Is this normal? It seemed pretty high up on the gauge to me. It's an 02 Sierra Denali with an lq4 if that helps. All stock except a k&n cai.

 

Were you sitting still when this occurred ? What was the outside temperature ?

 

Yes and 80

 

Normal, if you have not been moving for more than a few minutes. The engine heat will just soak in and because no air is flowing in past the front of the truck it will rise quickly.

When you are just bumming around or on the highway expect to see anywhere from 10-15ş above ambient temps, sometimes it's even closer to ambient.

 

This is exactly why most CAI look suspicious to me. The CAI I've seen pull air from inside the engine compartment, where the air will be hotter than pulling from behind the grille or fenderwell.

This may be off topic, but has anybody compared CAI performance by looking at what the IAT sensor is reading?

 

That's pretty high to me. I dont keep track of my IATs anymore, but when I was, I never remember seeing them anywhere past 120s. And that was after towing in the summer and turning the truck off for a few minutes and then back on.

Metal intakes will also tend to hold the heat more and longer than the plastic ones. I modified the box on mine to where there is roughly a 4x4 hole right behind the headlight. I dropped .1 in the 1/8 mile and my IATs usually stay within 10* of ambient while driving. During colder weather I have seen IATs the same or even 1-2* below ambient.

 

My IATS, never go over 100* even in Houston Texas heat.

Its very simple and cost efficient to lower IAT's.
There are a couple ways to do it.

CAI's:
My IAT's even at a long idle in a fast Food drive trough during a 90* + day never go 10* over ambient, and will drop to ambient with in seconds upon driving.
when driving they are at ambient the entire time.

I have used all sorts of CAI kits (volant to Specter) and have found the Specter to be the best, When its modded, Both IAT's and MAF gps, Huge gains above 4k rpms. After tuning my truck for the specter and switching to the Volant, My engine bogs and is hesitant from 2-3k rpm and is just sluggish above 3k.

My specter is Ceramic coated inside and out, both tube and box. Aswell as the Tube is wrapped with header wrap.
The box is Insulated with this on the outside.
Its cut so that it seals when I close the hood as well as around the CAI Tube.
You will also need to remove the steel plate that below the OEM filter box, this allows a huge straight shot of fresh air from in front of passenger side tire.
If you are worried about more dirt, mud, etc, use a K&N filter sock.

Recently a Friend did this mod, but he used high temp "hush mat" on the outside of his box, he had a very nice drop in IAT and to be honest it looks better, but is far more costly.

Btw, POS Volant is forsale, PM me for info.

Throttle body mods include the standard hot water bypas and ceramic coating it.
Intake manifold mods include, Ceramic coating and Insulating the bottom with Hush mat.

Do these simple mods and you will see a dramatic drop in both Idle and Cruise IAT's across the board as well as significant MAF gps gains at Idle and WOT.

 

My stock airbox in my Express has the IATs in the 160-170*F range at idle and I have Zero issues with it. As soon as I get onto the throttle the temps drop and once I am at highway speed they fall near to ambient.