upward trend in knock.

[powermyster]

hi guys,

just wanna run this by you guys and see what you\'s have to say,

i have my pfc in a few weeks now and mapped.  i noticed that for the first few days the max knock was bout 73   then in went to 79, 81, 86, and now the highest i\'m seeing is 89,

anyone any input on this.  if its picking up vibration is something getting looser. if so where should i look first.  

or is it nothing

[Gatesy]

replace the knock sensor, if your still getting high readings I\'d get it looked at sharpish.

[chrisJDM]

when do you get knock? is it only when you boot it? or just randomly? or at idle? or when?

[powermyster]

sorry i should have mentioned it always seens to be about 2500-3000 rpm. that it peaks in every gear. there is always soe degree of know there one i\'m above normal idle. but usually goes over the 60 around the above revs

[chrisJDM]

usually you would only get knock at higher revs when you are driving hard, if you are seeing knock at idle and low revs it is more likely to be a faulty knock sensor

[gsb876]

Either faulty knock sensor, or does your car backfire ?? if it backfires it will send the knock reading higher than possible, i saw 159 once :2Confused  after 2 loud backfires :Giggle

If neither of those get the map checked out as the figures you have mentioned are creeping into the danger zone

[ro284]

sorry i should have mentioned it always seens to be about 2500-3000 rpm. that it peaks in every gear. there is always soe degree of know there one i\'m above normal idle. but usually goes over the 60 around the above revs

i have the exact same problem,(same reading same revs) but mine\'s not mapped yet, running on a base map, waiting a DP fit, i thought it was the Knock sensor also. so fitted another and got same readings, i\'m hoping mapping will do the trick, but changing HT leads to magnicor. hoping it may help.

[powermyster]

where can i buy a knock sensor.  are they dealer only or is there better aftermarke ones available

it was showin similar knock patern before i got the map

[powermyster]

she hit 91 this morning.

[chrisJDM]

i think you can either get them from mazda but they cost about 100 quid, or you could get one from one of the tuners they usually have a few second hand ones.  

I dont think its worth trying to source a aftermarket one.

I got one from jimmys: http://www.jimmys-rx7.co.uk/

it was a couple years ago and i think it was about 30 quid

[powermyster]

thanks man i\'m gonna ring the guy who mapped it later today to see what he thinks

[tezz12345]

i get up to 90 but very low under boost so sure its my knock sencor

[chrisJDM]

i get up to 90 but very low under boost so sure its my knock sencor

certainly sounds like it, mine just use to flicker randomly mainly at idle then i had another fauty one, then the current one works fine, and i know it works, my car wasant fully mapped and when i took it up really high revs in 4th a while back it flickered slightly and i seen around 70 on the commander.

[lockwood77]

Around 70 is OK isn\'t it? I don\'t get the light flickering on mine at that (which is about the highest I\'ll see, 73 or 74 I think is the highest recorded).

[chrisJDM]

mine was only flickering but cause it was faulty, wasant getting true knock