what causes knock sensors to fail? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Javi802 · 11-23-2014, 07:22 PM

I know they are sensitive when it comes to dropping and that dropping one will most likely render it useless, but what, other than dropping one causes it to fail?

Can one that has sat for a couple of months "ruin" it?

I ask because when ever i first got my sr swap running and hooked up to consult, i had a code 34.

Replaced the sensor and didn't see the code 34 again.

Removed engine to do some shit and it sat for 2 months.

Put engine back in and I'm now getting a code 34 again.

Ive already bought a new sub harness and getting a new knock sensor as well. Should both be here this week

Im only asking because I'm curious.

angel mkiv · 11-23-2014, 11:17 PM

I would say in a normal circumstance heat would be its main wear factor..

*anti tyler* · 11-26-2014, 04:23 PM

Did you ONLY get a knock sensor code?

Javi802 · 11-26-2014, 04:58 PM

Yessir, thats the only code being thrown

***S14DB*** · 11-27-2014, 07:20 AM

Heat and Impact are the major ones. Rare case if you over Tq it you can deform it.

I see just as many Harness issues as the Sensor.

Javi802 · 11-27-2014, 09:33 AM

Well my engine never gets over even 180 degrees so i don't think heat is my issue.

Im hoping its just the harness. Being as the sensor i have is like 5 months old.

Im replacing both either way though sometime this week

godsmack · 12-02-2014, 02:15 PM

Do you have a loose exhaust? Noises from a loose exhaust can sometimes throw a knock sensor code.

Javi802 · 12-02-2014, 04:01 PM

Yes, actually i do. Im running an open down pipe with a "fabbed" L bracket that connects it to the tranny mount. It was pretty loose.

In fact today while driving, it came loose and started dragging and making a clonking noise. Freaked me the fuck out, thought my car started knocking until i pulled over and looked underneath.

I replaced my sensor and sub harness today though and reset the ecu. Went for a little drive around the area and rechecked the codes and still a 55.

I noticed the previous sensor wasn't clipped in to the harness all the way though. I could actually wiggle it. I believe i bent the little metal clip that holds it in when i previously replaced the sensor. Maybe it wasn't making a proper connection..? Who knows.

Kingtal0n · 12-02-2014, 04:29 PM

some engines sit for 8-10 years on a shelf from Japan before they find owners. And they usually fire up no problem.

Its always scary the first time you turn it over though.
fwiw- never had a knock sensor go bad on an sr20det.

Javi802 · 12-02-2014, 04:48 PM

Hmm.

Guess its a waiting game now to see if a code 34 comes back. Hoping it doesn't

11-23-2014, 07:22 PM	#1
Javi802 Zilvia Junkie Join Date: Jul 2012 Location: Oklahoma Age: 33 Posts: 472 Trader Rating: (10) Feedback Score: 10 reviews	what causes knock sensors to fail? I know they are sensitive when it comes to dropping and that dropping one will most likely render it useless, but what, other than dropping one causes it to fail? Can one that has sat for a couple of months "ruin" it? I ask because when ever i first got my sr swap running and hooked up to consult, i had a code 34. Replaced the sensor and didn't see the code 34 again. Removed engine to do some shit and it sat for 2 months. Put engine back in and I'm now getting a code 34 again. Ive already bought a new sub harness and getting a new knock sensor as well. Should both be here this week Im only asking because I'm curious.

11-23-2014, 11:17 PM	#2
angel mkiv Zilvia Addict Join Date: Sep 2009 Location: Seattle, wa Posts: 727 Trader Rating: (4) Feedback Score: 4 reviews	I would say in a normal circumstance heat would be its main wear factor.. __________________ Instagram username:angelmkiv

11-27-2014, 07:20 AM	#5
*S14DB* AFC #1 Join Date: Oct 2003 Location: 昨晩あなたのお母さんの家 Posts: 20,181 Trader Rating: (3) Feedback Score: 3 reviews	Heat and Impact are the major ones. Rare case if you over Tq it you can deform it. I see just as many Harness issues as the Sensor. __________________ Comments should be taken as Opinions not as Statements of Fact

11-26-2014, 04:58 PM	#4
Javi802 Zilvia Junkie Join Date: Jul 2012 Location: Oklahoma Age: 33 Posts: 472 Trader Rating: (10) Feedback Score: 10 reviews	Yessir, thats the only code being thrown

11-27-2014, 09:33 AM	#6
Javi802 Zilvia Junkie Join Date: Jul 2012 Location: Oklahoma Age: 33 Posts: 472 Trader Rating: (10) Feedback Score: 10 reviews	Well my engine never gets over even 180 degrees so i don't think heat is my issue. Im hoping its just the harness. Being as the sensor i have is like 5 months old. Im replacing both either way though sometime this week

12-02-2014, 02:15 PM	#7
godsmack Zilvia Addict Join Date: Feb 2009 Location: Allentown, PA Age: 39 Posts: 652 Trader Rating: (0) Feedback Score: 0 reviews	Do you have a loose exhaust? Noises from a loose exhaust can sometimes throw a knock sensor code.

12-02-2014, 04:01 PM	#8
Javi802 Zilvia Junkie Join Date: Jul 2012 Location: Oklahoma Age: 33 Posts: 472 Trader Rating: (10) Feedback Score: 10 reviews	Yes, actually i do. Im running an open down pipe with a "fabbed" L bracket that connects it to the tranny mount. It was pretty loose. In fact today while driving, it came loose and started dragging and making a clonking noise. Freaked me the fuck out, thought my car started knocking until i pulled over and looked underneath. I replaced my sensor and sub harness today though and reset the ecu. Went for a little drive around the area and rechecked the codes and still a 55. I noticed the previous sensor wasn't clipped in to the harness all the way though. I could actually wiggle it. I believe i bent the little metal clip that holds it in when i previously replaced the sensor. Maybe it wasn't making a proper connection..? Who knows.

12-02-2014, 04:29 PM	#9
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 42 Posts: 4,829 Trader Rating: (17) Feedback Score: 17 reviews	some engines sit for 8-10 years on a shelf from Japan before they find owners. And they usually fire up no problem. Its always scary the first time you turn it over though. fwiw- never had a knock sensor go bad on an sr20det.

12-02-2014, 04:48 PM	#10
Javi802 Zilvia Junkie Join Date: Jul 2012 Location: Oklahoma Age: 33 Posts: 472 Trader Rating: (10) Feedback Score: 10 reviews	Hmm. Guess its a waiting game now to see if a code 34 comes back. Hoping it doesn't