FYI - BeltTension Sensor problem
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Joined: Aug 2001
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From: Plano, TX
FYI - BeltTension Sensor problem
Hi all,
I went on an 850 mile road trip last weekend and, wouldn't you know it, the morning after I arrived I start the car and a horrible shrieking noise is coming from the engine compartment. The car sat out overnight in 25 Deg F temps so I thought (hoped) that when the motor warmed up it would cease. Not the case - the sound came and went - everytime I put load (acceleration) on the motor it would stop and sometimes when I pushed the clutch pedal. It seemed more prominent at idle than at speed.
The sound was coming from the general area of the alternator shaft so I thought the pulley/bearing might be going bad but the sound wasn't coming exactly from the alternator shaft area - rather from a bit to the left.
I felt that the car was drivable so I came back home and went to the dealership. Turns out it was a bad bearing - but it was in the belt tension sensor p/n 993.106.035.00. This part is a small wheel pressed against the fan belt and with an electrical connector on it - it apparently turns on the check engine light if the tension lets off should the fan belt break. Turns out this is a common failure (I have 42k miles on the car) and is easily replaced in 5 minutes with a single 5mm allen bolt. Part cost $48 w/PCA discount.
So - if you hear a shrieking whine from the alternator area don't panic - check the belt tension sensor wheel bearing. The new one is silent and smooth as glass - the bad one sounds like there's sand inside it when you rotate it and feels rough going around.
Ben
I went on an 850 mile road trip last weekend and, wouldn't you know it, the morning after I arrived I start the car and a horrible shrieking noise is coming from the engine compartment. The car sat out overnight in 25 Deg F temps so I thought (hoped) that when the motor warmed up it would cease. Not the case - the sound came and went - everytime I put load (acceleration) on the motor it would stop and sometimes when I pushed the clutch pedal. It seemed more prominent at idle than at speed.
The sound was coming from the general area of the alternator shaft so I thought the pulley/bearing might be going bad but the sound wasn't coming exactly from the alternator shaft area - rather from a bit to the left.
I felt that the car was drivable so I came back home and went to the dealership. Turns out it was a bad bearing - but it was in the belt tension sensor p/n 993.106.035.00. This part is a small wheel pressed against the fan belt and with an electrical connector on it - it apparently turns on the check engine light if the tension lets off should the fan belt break. Turns out this is a common failure (I have 42k miles on the car) and is easily replaced in 5 minutes with a single 5mm allen bolt. Part cost $48 w/PCA discount.
So - if you hear a shrieking whine from the alternator area don't panic - check the belt tension sensor wheel bearing. The new one is silent and smooth as glass - the bad one sounds like there's sand inside it when you rotate it and feels rough going around.
Ben
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From: St. Louis
Ben
Thanks for the post - something to remember before the panic attack
I remember Robin posting something about a bad belt tension roller switch causing an erroneous warning light. It was also suggested that the roller be periodically (& carefully) lubricated w/WD40, Teflon spray, etc. to prolong bearing life.
Thanks for the post - something to remember before the panic attack
I remember Robin posting something about a bad belt tension roller switch causing an erroneous warning light. It was also suggested that the roller be periodically (& carefully) lubricated w/WD40, Teflon spray, etc. to prolong bearing life.
