Not sure if this had anything to do with it, but my truck was surging during climb to operating temps, then seemed to stop once warmed up. Especially if not plugged in overnight.

I cleaned the IAT and MAP sensors and it has stopped and seems to be running smoother over all.

Is this a sign that I may need to replace my IAT soon?

Thanks

 

It could well be related. Usually poor mileage is the biggest factor with a dirty IAT sensor. As long as it is working well now, you should be good to go.

 

Do you know if the wear out or just break?

The small resistor in the plastic cage doesn't look like it does anything more than hang out in the manifold.

 

The IAT sensor element is called a thermistor and acts like a resistor that changes its value with temperature change. The IAT used in the Cummins will will decrease in resistance as temperature increases.

It is possible that the resistance of the thermistor is incorrect and this will effect how the ECM adjusts the timing and fuel delivery. Usually the thermistor will fail by becoming an open circuit and this will set the check engine light.

In my opinion cleaning the oil and carbon off the IAT element helps by removing an insulating layer that may slow the thermistor response to a changing air temperature.

 

Thanks Bent, I figured it was something like that. What would the buildup be from? Dirty intake air?

 

Separate but related question - will a bad or dirty IAT throw a code?

Thanks - Vic

 

A dirty IAT sensor will not throw a code. Mine gets nice and grungy from me using my exhaust brake, but I've never actually seen any measurable benefit to cleaning it.

Mike

 

If I am not running an exhaust brake, would there be any dirt/soot in there from any other source??

 

I have cleaned my IAT and noticed a noticable improvement in warm-up operation and fuel economy. I clean it and the MAP about every 30K.

 

MOPAR1973MAN.COM has a nice write up on cleaning the IAT and MAP!!

 

Mine is throwing a code now and then (1291). Liberal use of brake, hundreds of thousands of miles, maybe it's time to spray it off...

 

My dodge doesnt have a IAT next to the MAP. Just a plugged port for one.

 

i cleaned mine about a month ago and nothing changed and im wondering if the sensor is going bad cause since the temperature has started rising again has my fuel mileage started coming up again also

 

I did some fuel efficiency testing with the 180 degree t-stat, and found it massacred fuel efficiency (18ave/tank hand calced down to 14). I also found that colder weather hurt fuel efficiency perportionally to the warmup time versus run time.

In short, if I drove a short distance when it was cold out I did TERRIBLY on efficiency, where if I took a longer drive in the same cold weather my efficiency was worse than summer, but not too bad. This tells me that colder weather=longer warmup time, and colder engine=worse efficiency. However, though it looked bad on paper, the minimal amount of fuel consumed at a lower efficiency rate still made it impractical to hassle with the block warmer.

In short, IMO cold weather hurts fuel efficiency by extending warmup time. Sorry for getting so far off track. I don't *think* Kicker's problem is AIT related.

 

Winter blend fuel is also less efficient than summer blend