VEMS dirty 1.8t IAT sensor symptoms

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VEMS dirty 1.8t IAT sensor symptoms

Postby 88a5tq » Mon Apr 17, 2017 12:38 pm

So I wanted to share this scenario which I had previously attributed to my Hobbes switch activating the w/m injection at an inopportune time during part-throttle acceleration.

I believe that part of the problem comes from me having possibly slightly too small a k&n filter on the holset inlet due to space constraints. I guess I should've cleaned it last month when I thought my 2nd IAT sensor was breaking down in front of my eyes.

Symptoms were, when intake temps reached the 25 to 30 C area, the IAT sensor would read dramatic swings between 10 and 30 C several times per second. The result was strangely a lean fueling event that caused a lack of power. I cleaned the first sensor last month that showed the symptoms before installing it Saturday. The sensor that came out Saturday was showing the same symptoms of course.

After I changed the sensor out I decided to clean the nasty k&n for good measure. Problem solved lol. Glad it wasn't my engine prematurely eating those IAT sensors though!
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Re: VEMS dirty 1.8t IAT sensor symptoms

Postby chaloux » Mon Apr 17, 2017 4:59 pm

Are you oiling the filters? Don't.
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Re: VEMS dirty 1.8t IAT sensor symptoms

Postby 88a5tq » Mon Apr 17, 2017 5:06 pm

Yes I do but the problem has ceased since the cleaning but I suppose time will tell (a week?) If the oil messes with it again. That's what you're referring to I think anyway.
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Re: VEMS dirty 1.8t IAT sensor symptoms

Postby UrSobsessed » Mon Apr 17, 2017 8:24 pm

Oil on those type of filters will cause the kind of thing you're talking about. It happens over time, more so when the filter is over oiled. I stopped running oiled filters on my vehicles because of this kind of thing.
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Re: VEMS dirty 1.8t IAT sensor symptoms

Postby chaloux » Mon Apr 17, 2017 8:29 pm

Yep. There's lots of other options, although I understand k&n is available literally anywhere. A nice oilless AEM is what we used on Dad's build. They also have dealers all over the place.
Matt

01 Allroad 6speed - RS4 clutch, catless downpipes, stuklr tune
04 Jetta TDI - DC stage I clutch/14lb fw
DEATH by rust - 96 Audi A6 Avant 2.5l TDI
GONE :( 87 4ktq - 4 FOX SNAKES
DEAD :( - 1996 S6 mit TDI
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Re: VEMS dirty 1.8t IAT sensor symptoms

Postby 88a5tq » Mon Apr 17, 2017 8:43 pm

Sounds good. I guess until I can find something dry I'll just clean up the IAT like twice a month or thrice. Thanks for the warning guys :thumbsup:
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