Engine/Transmission (1998.5 - 2002) IAT sensor - check it occasionally

[John Berger]

My fuel mileage had been declining since last fall, nothing drastic, but slowly getting worse. I remembered a post from Alan Reagan, about a year and a half back and took my sensor out. It was filthy. I installed a new one and the fuel mileage went back to where it normally is. This thing was costing me 1. 5 - 2 mpg. This is a good regular maintenance check to add to the list. I sprayed the old one down with WD-40 and threw it in the tool box for a spare. It looked as good as new once I cleaned it.

 

[RustyJC]

I pulled and cleaned mine within the last month. With less than 12,000 miles on the truck, I was surprised how much "soot" was on it. It wasn't really gunked up, but it was certainly dirty. I sprayed it down with carb cleaner and it cleaned right up.



Since our truck is used almost exclusively for heavy towing, I think my situation is probably tied to lots of use of the Jacobs e-brake. Up to now, I would idle the truck with the e-brake on to warm it up while I was breaking camp and hitching up the 5th wheel - I'll probably not do so much of that any more!



Rusty

 

[John Berger]

Rusty, I didn't have an e-brake until three weeks ago, so it might just be the heavy towing. I average 16. 1 to 16. 5 mpg driving around town and to work. Since October it has fluctuated between 16. 1 and 14. 2 mpg. It started last fall but was ever so subtle, nothing drastic. I towed extensively last year so I'm thinking that could be the culprit. Regardless, I'm checking that puppy every 6 months. It's not that hard to do, and fuel is to expensive to give up that much mileage.

 

[damon]

sorry for the stupid question - but what is the IAT sensor and where is it ?

 

[CstlEng]

IAT= Intake Air Temperature sensor. It is located on the intake manifold next to the MAP (Manifold Absolute Pressure) sensor to the rear of the truck above the lift pump and behind the fuel filter.

 

[mberry]

Can someone post, or email me, a picture of where it is? I would like to inspect and clean mine. Thanks.

 

[Behr]

As John said at the beginning of this thread... . my mileage is also dropping.



I will be in the process of checking my IAT sensor... but couple of questions to the members.



First ... is it recommended to have a new IAT on hand before removing the old one... ??



Secondly... what is the best thing to clean them down with?? WD 40..... Carb cleaner... etc. . ??? How about GUNK... . the degreaser... ??



Hate to use anything that overtime will cause the IAT to physically breakdown and then next thing you know fragments of the IAT are sucked into the cylinder chambers... ... :--)

 

[gregdoerfler]

does somebody know the part # for the iat sensor from dodge?

 

[Hohn]

for degreasing, I use a product from Restomotive (the POR-15 guys) called Marine Clean.



It's simply the most amazing degreaser i have ever seen. it's SUPER concentrated, and water-based, so it won't hurt plastics or anything except grease.



Don't get too happy with it-- it takes a lot of water to rinse... maybe it's a little TOO concentrated. .



NAH!!!





HOHN

 

[John Berger]

I used WD-40 this time around, but did not install that sensor. I kept it as a backup. I also used dialectic grease at the connector. The sensor is at the back of the engine on the driver's side.

 

[davemac]

mberry,

try thishttp://www.dodgeram.org/tech/dsl/sensors/IAT/clean.htm

 

[Mschevey]

Some people have moved the sensor to a different location. I believe Marco was the first to do this. You can drill and tap the right size port into the upper portion of the air horn. This moves it away from the valves and the soot that is allowed into the intake.



Mike

 

[Big White Beast]

Had the opportunity......

To get some pics. This engine was sitting on a pallet which made it easy.



IAT part # 05014197 AA



Garrett



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[Behr]

Originally posted by Mschevey

Some people have moved the sensor to a different location. I believe Marco was the first to do this. You can drill and tap the right size port into the upper portion of the air horn. This moves it away from the valves and the soot that is allowed into the intake.



Mike

Does not moving the IAT to another location defeat the purpose behind the sensor?? It seems to me the ECM should be getting the air temp just before entering the combustion chamber.



I can see why it sounds great to move it to prevent the build up of soot ... . etc. I think while we do our regular oil changes that it would be a good time to pull out the IAT sensor... . give it a quick clean... and re-install it. Now you have a clean IAT... . and its in a location that it was designed to be in, and now the ECM will control the fuel air mixture to optimum levels.

 

[Turbo Horseman]

I'm with Behr on this one.

 

[Gary - K7GLD]

OK - another dumb question - WHAT gets the IAT dirty to begin with? Seems that a good air filter SHOULD keep the intake tract nice and clean - and no need to worry about the IAT getting dirty - or do the trucks in question have some sort of EGR setup that brings dirty exhaust air back into the intake? AND, if THAT is the case, do those of us WITHOUT and EGR junk need to be checking ours as often?

 

[John Berger]

Gary, my truck is a 1999 model. No EGR. The fuel mileage started to deteriorate last November. I had approximately 83K miles on the truck. Relatively speaking, that's not to bad for a twenty dollar part.

 

[Whitmore]

Dirty IAT is in direct relation to exhaust brakes and carbon buildup, I clean mine every 10k and it is carboned up every time.

 

[Behr]

Originally posted by John Berger

Gary, my truck is a 1999 model. No EGR. The fuel mileage started to deteriorate last November. I had approximately 83K miles on the truck. Relatively speaking, that's not to bad for a twenty dollar part.

John... . did you notice an improvement in your fuel economy once you cleaned it... . ??



I was debating on whether to clean mine or just buy a new one... .



I saw a post somewhere that showed the Ohm readings with temperatures... ... could be interesting to throw an Ohm meter on and take a few reading... before and after it was cleaned... ...



Also... do some of these trucks have EGR valves and some don"t... ???

 

[Mad Bomber]

AIT

Al at piers said that you should clean map & ait at least every 6months if you have a Ex- brake it should be more,also he said use carb cleaner. Eric