I figured out why the IAT has been high

[saratoga]

I pulled out the IAT sensor today because the temp has been showing really high since the issues with the turbo earlier this month. It would climb to 175 idling in traffic (way higher than normal) and stay there when it would have normally come back down instantly once I started moving again.

Anywho, I pulled it out and it was covered with a good 1/8" of freakin soot! No wonder it hadn't been responding the way it normally did in the past.

Wiped the soot off, screwed it back in and we'll give that a whirl this week to see if there's any difference in the IAT now. Ought to be a good test since temps have been over 100* all week.

 

[btfarm]

Blowback from the VPS not functioning right? Not sure where the IAT sensor is though.

 

[saratoga]

The soot is from the EGR.

It's buried way down in the valley on top of the upside down Y looking piece where the intake splits between the two cylinder heads. You have to take the plastic intake pipes and the turbo mouthpiece off to be able to see it.

 

[BoostN]

I don't have my PVC rerouted so I can only imagine what mine looks like.

 

[killerbee]

Sounds normal. I have a log or 2 of over 250F post-CAC. Over 300F on grade. CAC heat soak is complicit. Experiment with turning AC on and off, that will be fun to watch.

Airbox temps of 140, plus a 30 degree condenser rise, and 175 is not too bad in hot weather.

 

[Unit453]

I always thought the MAF reads the intake air temps. I always *assumed* thats where they come from because they're so friggen high.

 

[killerbee]

There are 2 IAT sensors. The reading in the plenum should be well dampened. The reading at the box will be all over the place with stop-go conditions.

 

[Unit453]

In the box, it where, the MAF right? So when we're reading the IAT's, where is it reading from exactly?

 

[Mad Maxx]

I dunno, but I Monitor 2 IAT Sensors in my Truck.

1 is In the "Tube" and the other is After the "Tube". They are usually about 10* Apart from each other.

 

[saratoga]

The one most tuners monitor is IAT #2- the one in the intake.

IAT #1 is in the MAF.

 

[killerbee]

What are you guys are referring to? If using EFILive, then there is AAT and IAT with bosch. AAT is monitored at the MAF location. Going on old memories.

 

[Turbine Doc]

Well being a D-Max neophyte, I may be stating the obvious here, how about unplugging the #2 sensor and see if your EFI live goes "dumb" for the IAT reading,

That IMO would be the best way to KNOW which does which rather than guessing at it, or trying the memory bank, which in my case is suspect; as after consumption of many "adult beverages" when I was but a mere sea-pup back in my USN days I now suffer from advanced CRS from time to time.

Now I'll slink back to Jurassic Park land

 

[saratoga]

Did it make a difference? It sure did.