Friday, November 02, 2007 - 08:33 am, by: Mike Bradberry(Halflife)
Is there an easy way to check knock sensors and where are they, and what do they look like and how much are they to replace? I have occasional pinging and want to eliminate possible causes.
Friday, November 02, 2007 - 10:52 am, by: Tim Appleton(Timbo)
I'm not sure that there is an easy way to check the operation of knock sensors, maybe connect up an amplifier and listen to the output??? Just don't go blowing up the amp... They are located in the valley of the block from memory, below the inlet manifold so they're not easy to get access to without removing stuff. There are about 8 or so bolts plus fuel connections to remove before you get the manifold off.
They look like a large hex head nut with wires coming out the top of them as they are only microphones that are attached to the block. If you had access to a CRO then you could check the output to the ECU. The output should look like noise, and if they're not working then i guess there will be no noise.
Can't help you with cost.
You might try running a few tanks of a fuel with good detergent properties to try to clean out any carbon build-up as that's a possible cause of knock. I don't run anything less than 95 octane or my motor will ping.
Friday, November 02, 2007 - 07:51 pm, by: Mike Bradberry(Halflife)
Thanks Tim. Lots of what you said is a little too technical for me though. I have had it checked on a dyno, and the only thing to come out of it was maybe a slightly weak knock sensor, but it sounds too difficult to remove and replace on a 'maybe'. I always run 98 octane fuel, but don't have any problems using 95 either if I have to. It's one of those intermittent problems that's a bugger to trace.