Knock sensor goo?

vrracing · 10-21-2013, 01:06 PM

The car wouldnt start right away this morning and then sounded like it was missing. So I put the timing light on the leads and rear trailing wasn't firing. Looked at the plug and the ceramic was coated in brown sticky goo. It seems to have come from the knock sensor whose backing is squishy.

Replaced the plugs and it runs perfect again. Dont know if the goo is conductive or not or if it was all a coincidence.

I saw someone in the FD3S forum had their knock sensor oozing out and they said they were going to fill it with silicone. It's been two years and he never reported back. Any one know if that's a workable approach? The car never seems to detect knock so it appears to be working for now.

Thanks

Rotary Evolution · 10-21-2013, 02:02 PM

likely coincidental and the plug was fouled.

you can epoxy over the end if you wan't to keep it from leaking further but it may affect the sensitivity of the knock sensor. being on the FC that it is hardly a critical component i doubt it would hurt much.

Pete_89T2 · 10-21-2013, 04:05 PM

Quote:

Originally Posted by vrracing

I saw someone in the FD3S forum had their knock sensor oozing out and they said they were going to fill it with silicone. It's been two years and he never reported back. Any one know if that's a workable approach? The car never seems to detect knock so it appears to be working for now.

Thanks

I've got the knock sensor goo problem also, but I never had a problem with no starts or ignition misses. FWIW, the goo in my knock sensor appears to be dripping out from the junction where the wire enters the sensor body - the backside of the sensor is still intact & solid. The goo happens to be melted potting compound that is used to seal & protect electronic devices from the elements, so the silicone approach should work fine. I wouldn't try to fill it though, maybe just apply the silicone externally over the portion that appears to be leaking.

vrracing · 10-21-2013, 05:15 PM

Cool guys, thx.

10-21-2013, 01:06 PM	#1
vrracing Rotating Assembly Join Date: Oct 2008 Location: TX iTrader: (0) Posts: 102 Rep Power: 17	Knock sensor goo? The car wouldnt start right away this morning and then sounded like it was missing. So I put the timing light on the leads and rear trailing wasn't firing. Looked at the plug and the ceramic was coated in brown sticky goo. It seems to have come from the knock sensor whose backing is squishy. Replaced the plugs and it runs perfect again. Dont know if the goo is conductive or not or if it was all a coincidence. I saw someone in the FD3S forum had their knock sensor oozing out and they said they were going to fill it with silicone. It's been two years and he never reported back. Any one know if that's a workable approach? The car never seems to detect knock so it appears to be working for now. Thanks __________________ 90 S5 Vert. JDM Tii with BNR Stage1 turbo. Pineapple Racing street port. Bonez cat-forward. Corksport cat-back with Vibrant UltraQuiet resonator. RTek 2 wZeitronix w/b. HKS EBC. Vis CF Tii hood. 3000GT wing. Ground Control coilover kit with KYB AGX shocks. Red and Black leather RX8 seats. Corksport Odura lip & bumper caps, OEM Tii skirts

10-21-2013, 02:02 PM	#2
Rotary Evolution rotaryevolution.net Join Date: Feb 2011 Location: Las Vegas, NV iTrader: (0) Posts: 248 Rep Power: 14	likely coincidental and the plug was fouled. you can epoxy over the end if you wan't to keep it from leaking further but it may affect the sensitivity of the knock sensor. being on the FC that it is hardly a critical component i doubt it would hurt much. __________________ http://rotaryevolution.net

10-21-2013, 05:15 PM	#4
vrracing Rotating Assembly Join Date: Oct 2008 Location: TX iTrader: (0) Posts: 102 Rep Power: 17	Cool guys, thx. __________________ 90 S5 Vert. JDM Tii with BNR Stage1 turbo. Pineapple Racing street port. Bonez cat-forward. Corksport cat-back with Vibrant UltraQuiet resonator. RTek 2 wZeitronix w/b. HKS EBC. Vis CF Tii hood. 3000GT wing. Ground Control coilover kit with KYB AGX shocks. Red and Black leather RX8 seats. Corksport Odura lip & bumper caps, OEM Tii skirts