Engine/Transmission (1998.5 - 2002) IAT Sensor........faulty?

[kboettcher]

Could someone enlighten me? I seem to be getting quite abit less fuel mileage than what most people are saying they get. I'm getting about 17mpg on the highway and about 15 in town. Keep in mind that I live in Canada, so I should actually be seeing a little more than you guys south of the line because our gallon is larger than the U. S. gallon. A freind at work has a '97 Cummins and he said he gets up to 28 on the highway if he holds it at about 60mph. From all the stuff I have been reading here and on Dave Fritz's Page (BTW that is one hell of good website http://dodgeram.org/ ) I was wondering if it could be my IAT sensor? So I took it out to clean it but it was spottless so I decided to ohm it out with my multi-meter. The readings I got were quite different than the ones Dave has posted on his site http://dodgeram.org/tech/dsl/sensors/IAT/clean.htm. I checked mine at 65 deg F and only read 13 ohms, does anyone think it could be a bad sensor, seems alittle low to me. Could this cause bad fuel mileage?

 

[KatDiesel]

Do you get this milage yearround? Or just in the cold months? The blended winter diesel will lower MPG. I have dropped from 16mpg to 15mpg around town. The station I use has 70/30 blend.



But yes its possible your IAT sensor could decrease milage.

 

[kboettcher]

I've only had the truck for 1 month so it's hard to say, but I don't think the place I get my fuel does the winter blend, it doesn't get all that cold here. I'm in the southwest coast of B. C. Canada

 

[Marco]

When I pulled my IAT the first time it's readings were off slightly.

I then replaced that sensor and got a 1. 5Mpg better mileage.



One thing that caught my attention when I tested the two sensors (old & new) side by side, was that the new sensor reacted MUCH faster to temperature variations.



A new sensor is only 20 bucks. Get a new one!



Marco

 

[WestTN]

faulty sensor

Your sensor is bad if that reading is correct. I don't have my figures with me right now, but I do remember that it should be somewhere close to 20kohms. I believe mine read read about 25 or 26kohms at 72 degrees Fahrenheit.

 

[kboettcher]

Where are you getting a new sensor for $20?

I checked both Dodge stealers here and one was $43 Canadian. and the other one was $56 Canadian. So I thought I would be a smart guy and go to the Cummins dealers, the first one wanted (are you ready for this?) $96:--) . The other one was $84. So I went to an auto parts dealer in town and they got me one in the next day for $22 Canadian (thats about $1. 50 American ). It isn't a Cummins oem but made by Blue Streak, which are supposed to be pretty good for aftermarket parts. Has anyone used anything but Mopar or Cummins on this part?

 

[pwr2tow]

Changed mine almost two years ago, $23. 00 at dodge dealership, and almost 3 MPG increase towing, Mileage was minimal increase not towing.



Thanks to Marco for this one.



Ron

 

[JCyrbok]

Getting to IAT

IAT is next on my list of hopeful solutions to falling MPG ( not chalked up to winter).



Re torqued the intake cover bolts and found that they were all way loose. 2 took atleast full turn to get to 18 lbs/ft.



Went to pull IAT and found that I could not get my arm back to it from the driver fender, standing on step ladder. Too many large wire bundles and a bracket for throttle cable in the way. What is the best way to get to it? Looks like maybe a clear shot from below but dont think my arm will reach. ANy thoughts or tricks?



Also I will replace it if it is out of spec but if it is not I will clean it. I have Electrical Contact cleaner, will this work instead of Carb cleaner? ONe warning on the can says dont use on "polycarbonate" plastics any worry with the plastic of the sensor?



Thanks

J-

 

[2-ND TIME]

Intake air

In one of the TDR Mags there was aprint out of the readings of the temp vs resistance I can find it for you If you would like? The readings are very low . The milage readings are close to what mine are up North of you. The dealer**** I mean ship too technical for them to do !!!!!!! replaced mine when it wasn't nessecary and it was right in the ball park when I measured them with a meter.

 

[kboettcher]

Hey guys, just an update. I got a new IAT sensor in from the stealer... uhh dealer, they said it listed for $43. 60 but gave me a deal for $36. 00(woohoo). I took it to the shop and tested it on the bench with the old one right beside it. Let them both climatize together (sounds a little dirty... doesn't it?) and when I checked them with the ohm meter and the infared temp sensor, they were the same (13 ohms @ 65 deg F). Still seems low if that list of readings is correct. Wonder if the new one could be bad? I installed the new one anyway. I'm hoping to get the cables for my laptop and the OBD-II software soon and check it with that. I went to the OBD-II site and downloaded the free software and tried the sample demo scan... . and think it looks quite handy. Just need the hardware now... has anyone out there got this, and if you do, how do you like it?

 

[2-ND TIME]

IAT sensor

Will send info on the IAT resistance tomorrow yes they both sound US !!! Take your meter to the dealer and measure them and hope to find one that is good. If not get him to order a good one for you.

 

[kboettcher]

Hey 2nd time, how far north are you? I have relatives in Fort St. John and Atlin. BRRRRRRRRRRRRR... . cold up there right now.

Yes I will take that one back and take my meter with me... . never thought of that

 

[Mad Bomber]

IAT

In talking to Al at piers he said that you need to clean IAT atleast every 6months

 

[Rob Thomas]

Re: IAT

Originally posted by E Waagener

In talking to Al at piers he said that you need to clean IAT atleast every 6months

Yea, or you can relocate it to the intake horn, mine has been there for quite awhile, no problems, and clean. Marco, didn't you do this? Edit: here's the link to the relocation. . https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=56694&highlight=ait+sensor



Later, Rob

 

[2-ND TIME]

IAT

Sorry Kboettcher will have to get girlfriend to look for the info she is on the phone to my parents and will tald to her shortly. You were right FSJ.

 

[2-ND TIME]

IAT sensor

Sorry for now answering you sooner but the virous that has been around for several days has murdered the computor at work. For after e-mail sign in try to enter and you get Do you want you financial Report or do you want mailing options NO,NOOOOOOO Throught this computor out the oi?/()##^&)( So hope that you weren't plaged with this. ENOUGH said. Issue 34 page 46 Please read TEMP and resistance for I can't put this in a coloum T 32 30700 to 36600,,, T 77 9300 to 10700 ,,, T 122 3300 to 3800,,,T 167 1100 to 1300,,, T 212 625 to 647 OHMS So hope this helps and sorry for being so long is replying.