Intake Air Temp Sensor
 

Hello,

Can someone please confirm where this part is on a 1990 300E?

In the air intake hose before the air cleaner?

Thanks.

Kind regards,

chicago124 -- 1990 300E 134k Miles

Chicago:

I was gonna pop the hood on my MB, but Garfield is on it sawin' a log. Didn't have the heart to wake him.

Anyway, it's pretty easy to spot. Open your hood and follow the black air intake up toward the air filter housing. It's maybe 6" before the air filter housing on the right side(looking towards windshield). In my case you squeeze a couple of small plastic locks on each side; then turn to remove.

Hello,

Mike: Hope Garfield had a good nap:-) Thanks for the clarification. That's what I thought.

mpnye: Perhaps you are confirming the part?

Thanks for the help. I gather this needs replacing sooner rather than later.

chicago124 -- 1990 300E 134K Miles

Hi,

Pulled the sensor and just for kicks, I measured resistance across the two poles. Got a reading (forgot what it was) though.

Is there a specific resistance reading for this part? Or perhaps another measurement. I measured the voltage at the IATS plug and got a reading there too. I think anout 4 volts.

Reinstalled sensor after cleaning it off and I still get a 81.36% reading at pin 3 -- X11 connector.

Any thoughts?

chicago124
1990 300E 134k miles

Hi chicago124,

I believe the resistance varies based on the temperature, but I do not know what the specific resistance should be at lets say 32 or 60 degrees F.

Hope this helps anyway.

Reinhard Kreutzer

I can tell you in " generic " terms, that temperature senders ( water, aircharge, etc. ), normally read high ohms, say about 10 k ohms, when cold, and then drop to about, oh, say 400 - 500 ohm at " normal " operating temperature.
I know this is pretty vague, but at least it gives you an idea what it's all about. ;)

<<Hi,

Pulled the sensor and just for kicks, I measured resistance across the two poles. Got a reading (forgot what it was) though.

Is there a specific resistance reading for this part?>>

Easy test for reading is to let it stand at room temp [ 20C=68F]
for a while and then check it...
Looking for 6060 ohm, +/_5 %