Knock sensor [Archive] - Nissan Xterra Forum

: Knock sensor


misseysmommie
10-16-2011, 11:06 AM
I have an 02 xterra. The check engine light came on and the guy at the auto parts store who did the reading said the knock sensor was bad. The part is $116.00 I told him I dont have anyone to change it. He said to google it. Is it really going to be that easy to change it?
Thanks in advance!

drbandkgb
10-16-2011, 11:22 AM
Welcome in to CX..

No the Knock Sensor is a PITA.. its under the intake. And a knock sensor shouldnt throw a service engine code.. Its a P328 I believe..

What were the codes?

misseysmommie
10-16-2011, 11:59 AM
the codes were PO328 and PO455

drbandkgb
10-16-2011, 12:00 PM
PO328 is the typical KS code.. It will not bring up a engine light..
Ill let others pop in and explain the PO455

misseysmommie
10-16-2011, 12:04 PM
Thanks!:smile:

Coxterra
10-16-2011, 01:08 PM
Search for P0455. There is tons of info on this site about both of these codes already. I think it's an EVAP leak or something along those lines. If your X doesn't have a supercharger, I wouldn't worry about the KS code.

misseysmommie
10-16-2011, 01:32 PM
Its a supercharge

drbandkgb
10-16-2011, 03:11 PM
I still do t know that I'd worry over it.. Some say the KS kills the sc.. It's debatable

Jason2o
10-16-2011, 03:33 PM
I know I am a Noob on this site but not new to cars or boost or even m62's , anyhow knock sensor codes or issues and running boost are a bad combo. The use of boost increases the possibility of detonation and factory boosted vehicles without (computer controlled) boost control will richen the mixture to reduce detonation because they cant decrease boost. This is why supercharged cars running low octane gas or with a bad knock sensor get worse mpg than a naturally aspirated with the same malfunction or situation.

Another problem I am not sure the OP knows about it, there is a coupler in the m62 and "some people" (myself included) believe that this coupler wearing out may lead to more noises bieng translated to the knock sensor and it sending signals of detonation to the computer. This may also lead to early death to the s/c and the knock sensor. There is a Eaton oem coupler Kit on ebay its only $31 with oil included... Much cheaper than knock sensors, unless you cheap out on them.. $36...

Good luck, Id do the Knock sensor, coupler, oil and supercharger bearings... but I am an aviation tech that has experience rebuilding turbines...

-Jason2o

Camo500EFI
10-16-2011, 05:50 PM
I had the same issue with my 2002 non SC, it was throwing a knock sensor code or atleast what the Autozone folks told me. Long story short I did new plug wires and never saw the code again. Lets just say I really don't ever want to another nightmare like trying to find the damn thing again.

drbandkgb
10-16-2011, 07:16 PM
I know I am a Noob on this site but not new to cars or boost or even m62's , anyhow knock sensor codes or issues and running boost are a bad combo. The use of boost increases the possibility of detonation and factory boosted vehicles without (computer controlled) boost control will richen the mixture to reduce detonation because they cant decrease boost. This is why supercharged cars running low octane gas or with a bad knock sensor get worse mpg than a naturally aspirated with the same malfunction or situation.

Another problem I am not sure the OP knows about it, there is a coupler in the m62 and "some people" (myself included) believe that this coupler wearing out may lead to more noises bieng translated to the knock sensor and it sending signals of detonation to the computer. This may also lead to early death to the s/c and the knock sensor. There is a Eaton oem coupler Kit on ebay its only $31 with oil included... Much cheaper than knock sensors, unless you cheap out on them.. $36...

Good luck, Id do the Knock sensor, coupler, oil and supercharger bearings... but I am an aviation tech that has experience rebuilding turbines...

-Jason2o

The KS in the 3.3 almost came from the factory not working right.. There are many threads debating the knock sensor issue in CX.. That 31$ part will take you a weekend to get installed.. The knock sensor is under the SC and intake.. IF your going that far.. change the plugs and wires.. There is also a by pass for this.. Check the DIY section on the how too.
As for running a low grade gas in the SC.. Thats a no no from the factory.. ONLY run High grade..

drbandkgb
10-16-2011, 07:50 PM
RacerXXL found this... check it out to see where the coupler is located in the M62.
http://www.youtube.com/watch?v=pSsSctYvOoI

Coxterra
10-16-2011, 08:06 PM
I had my KS replaced and notice almost no difference to be honest.

MechPatt587
10-17-2011, 02:20 AM
When I first got my X it had the KS code. It is not SC, but I don't like having codes in the computer so while I was going to diesel school I used the shop there and did the replacement. It took me and a helper about 12hrs total to do the job, but I also meticulously cleaned the plenum, lower intake, and fuel injector tips of every trace of carbon build up... every part looked brand new when I put it back on... I also replaced the plugs and wires while I had the motor tore down...

Itsme
10-17-2011, 10:44 AM
The Po455 is a gross leak from the evap system. Could be a hose off or clogged or the plug on the rear evap canister is unplugged.
There me be other things also, but all in the evap system.

Hi and welcome to Club X

Jason2o
10-17-2011, 01:50 PM
The KS in the 3.3 almost came from the factory not working right.. There are many threads debating the knock sensor issue in CX.. That 31$ part will take you a weekend to get installed.. The knock sensor is under the SC and intake.. IF your going that far.. change the plugs and wires.. There is also a by pass for this.. Check the DIY section on the how too.
As for running a low grade gas in the SC.. Thats a no no from the factory.. ONLY run High grade..

Almost not working? Most of the xterra and other cars I read about starting to have issues are well over 60k or 5+ years old, thats not a straight from the factory issue. The issue on the xterra is that the KS is right under an M62 Eaton that is suppose to be maintainance free, and in actuality needs to be maintained with oil and a coupler. I have rebuilt a few M62's and I had an SVT Focus I put the JRSC BBK on, they all didnt have a KS that friendly with the supercharger.

As for ignition, I would hope that someone who was getting a KS code would change the plugs first, that is probably one of the first things anyone who buys a used car should do. Having a cylinder only fire off-time due to the compression and not the spark will surely not help the KS.

The video is helpful but this is a pretty common check and usually how a mechanic is able to scare someone into buying a new S/C, lol..

As for the low grade... Yes running high grade or premium is a from the factory requirement, the problem is not all 93 octane is 93 octane.. The KS is there to help keep the engine safe if it should encounter really bad gas, low octane or a mechanical malfunction. There are otherways to simulate high octane gas through methane/water spray kits etc..

Removing an Intake could take a weekend for someone who is first enccountering mechanic work but it really isnt that huge of a job. Also spending some time replacing the gaskets and taking a look see in the intake and supercharger could help people understand the condition of the vehicle they drive.

The reality of all this is How hard is it to remove the S/C belt and lay hands on the Pulley? Not very hard, do that first and then order the parts ( less than $40 shipped) r&r the coupler (very easy very quick job) and see if that fixes it. If it doesnt than maybe take the next step?

-Jason

drbandkgb
10-17-2011, 04:13 PM
Almost not working? Most of the xterra and other cars I read about starting to have issues are well over 60k or 5+ years old, thats not a straight from the factory issue. The issue on the xterra is that the KS is right under an M62 Eaton that is suppose to be maintainance free, and in actuality needs to be maintained with oil and a coupler. I have rebuilt a few M62's and I had an SVT Focus I put the JRSC BBK on, they all didnt have a KS that friendly with the supercharger.

As for ignition, I would hope that someone who was getting a KS code would change the plugs first, that is probably one of the first things anyone who buys a used car should do. Having a cylinder only fire off-time due to the compression and not the spark will surely not help the KS.

The video is helpful but this is a pretty common check and usually how a mechanic is able to scare someone into buying a new S/C, lol..

As for the low grade... Yes running high grade or premium is a from the factory requirement, the problem is not all 93 octane is 93 octane.. The KS is there to help keep the engine safe if it should encounter really bad gas, low octane or a mechanical malfunction. There are otherways to simulate high octane gas through methane/water spray kits etc..

Removing an Intake could take a weekend for someone who is first enccountering mechanic work but it really isnt that huge of a job. Also spending some time replacing the gaskets and taking a look see in the intake and supercharger could help people understand the condition of the vehicle they drive.

The reality of all this is How hard is it to remove the S/C belt and lay hands on the Pulley? Not very hard, do that first and then order the parts ( less than $40 shipped) r&r the coupler (very easy very quick job) and see if that fixes it. If it doesnt than maybe take the next step?

-Jason

Jason you have to understand.. Many members on these boards do not have years of mechanical exp. Just because you may doesnt mean others do.

The KS issues is not just for SC Xterras.. The basic 3.3 has a KS that fails from the get go too..

This is a link to the SC KS bypass LINK! (http://www.clubxterra.org/forums/showthread.php?t=30061&highlight=knock+sensor+by+pass)