Engine compartment purge fan comes on too early

[jchapura]

2005 C2S about 80000 miles

 

What are the possible causes for the engine compartment purge fan to come on early? The old sensor exhibited the same thing. The new sensor is about a month old.

 

I was checking the cam deviations with my Durametric and I noticed the fan come on only after about 5-10 minutes after the engine had started up (from a true cold start). The ambient temperature was about 55 degF. The Durametric showed the engine compartment temperature about 41-44 degC (much cooler than I thought was supposed to kick on the fan).

 

[Loren]

Those darn holders for that sensor are constantly problematic. They fall out often.

You could try a new grommet 993 110 530 01 about $3.48 USD.

[jchapura]

Thanks Loren. The grommet is holding the sensor ok in its natural position. I check it quite often since my fan being on really gets my attention.

 

I was thinking of 1) reversing the sensor position or 2) insulating the sensor tip. All in the hope of delaying the fan start to its design value.

 

Is it possible another temp sender (oil, coolant?) is broken that is part of the purge fan control logic?

 

Edited February 12, 2020 by jchapura

[Loren]

Pretty much the only thing that controls the deck lid purge fan is that sensor.

 

[WTL]

where is the sensor located?

[Loren]

2 hours ago, WTL said:

where is the sensor located?