FD3S Knock Sensor

[kariayam]

Hi Guys,

How do U Guys consider this FD3S knock sensor condition? (the insulator seemed melted over the heat of a Rotary Engin).

1- Bad?
2- Repairable(reapply silicone sealent on the melted area)?
3- Still working well though it looks horrible?


I was experiencing a knock level higher than normal during WOT lately. The level can be read thru Power FC commander.

Normal value was 24-27... hardly reach 30
Lately it easily reaches 47

though there are few things that may contribute to the high knock reading, I may want to start investigating from the sensor itself first..In case the bad sensor condition will pick up wrong knock signal..

Only then I'll start with the fueling and ignition...

 

[Alchemis]

it happened the same to me as well... previously.... the knock level shot up to 100 at certain point of RPM.... but i was running like that for like 3 years.... no issues.... just omit it... disable the know sensor warning... i doubt it can be replaced.

 

[kariayam]

it was actually due to fouled spark plugs... replaced them and the knock number went normal below 30 again...

 

[spooled]

btw on a fd3s.. what is that blinking TEMP light on the left side of the instrument ??
it blink tremendously everything i hit high rev.. is it a knock?

 

[kariayam]

btw on a fd3s.. what is that blinking TEMP light on the left side of the instrument ??
it blink tremendously everything i hit high rev.. is it a knock?

I think the blinking TEMP light you mentioned is 'Catalytic converter overheat' a.k.a center bullet which i believe has been removed in most of FDs with aftermarket/upgraded exhaust system(down pipe,mid pipe etc..).. sometimes the remaining wire for that sensor which are mostly buried under the driver seat had a metal to metal contact ( with chassis/ seat railing etc..)..

If u are using power FC, the Power FC will blink the check engine light if it detects knock more than 100(can be displayed on PFC)..

If u are hitting the rev limit, a buzzer will sound telling u that u are already reach the rev limit ...may be around 7.5k to 8k RPM..

Anyways, better go have a check..Goodluck...

 

[spooled]

shockingly my pfc doesnt have the commander...thanks to joewe la!!!! how to see.. lol. wait for check engine lights? :P

 

[Horny93]

Ya mine the same. The knock will be 100plus around 3000rpm. Just did a dyno and the guy said it's not caused by AFR setting. The fueling is sufficient but the knock sensor goes crazy around 3000rpm. Was asked to check if there's anything loose in the engine compartment. Any suggestions? Kinda frustrated that the PFC knock display is not reliable.

 

[RERider]

order new part from Mazda