Knock Gage stop working...HELP

[Chris McDade]

Well the reason Im replacing head gaskets right is because my knock gage stop working the last time I was at the track.

I have the block box knock gage. With the read light and it beeps when you get any knock. When I turn the key on it beeps and works. It has a test button on it and it works. I press the botton and it beeps like its suppose to. ( So im thinking that this thing is working ). Well I get a hammer and go and hit the block and it does not beep at all. So I replaced the knock gage with a different one I had and it's doing the same thing.

I've already check the wires going into ECM and they all are connected.

Do you think that it's the sensor on the back of the block or a bad ground some where????

Any other sugustions.

Thanks an advance

 

[WarpSpeed]

Or the ESC box/module over on the PS fender, that the knock sensor hooks in to. I'd pick ESC module.

 

[Chris McDade]

What does the ESC module look like? Where can you buy them and how much are they? Do they usaually go bad??

Thanks in advance

 

[Carolinaturbot6]

Well, it's probably one of the following:

1) Knock sensor itself....if you've never replaced it, I would. Even if it turns out to be ok right now, having a new one is certainly a good idea.

2) ESC sensor...recieves a signal from the knock sensor telling it that detonation is happening.

3) ECM....gets a signal from the esc sensor telling it to cut back timing to stop the detonation.

A quote from a TR manual: "A loss of the knock sensor signal or a loss of ground at the ESC module would cause the signal at the ECM to remain high. The ECM would control ignition timing (EST) as if no detonation were occurring."

One simple way to check this is to hold the throttle steady between 2000-2500 rpm and give the engine a couple of raps with a hammer or similiar tool. (Just don't bash it!) You should be able to notice the rpm's drop a little as the ecm retards the timing.

 

[Chris McDade]

Thanks Carolinaturbot,
I will check those things out.

What does the ESC module look like? What kind of plug does it have on it?

Thanks

 

[Carolinaturbot6]

Its over on the passenger side fender/firewall...it is held on with 4 little screws, and is the sensor that is closest to the Heater box....has a rather large connector going to it!

Let me find and paste a page from GNTTYPE that might help. Give me a minute. http://gnttype.org/maint/sensors.html#TOP

It's sensor #16 in the picture diagram above. HTH

 

[Chris McDade]

Sweet... Thanks , That helps alot. I will let you know if that works.

Thanks


Anyone know how much those modules are????

 

[Carolinaturbot6]

Poston's has em listed for $66.88 in their catalog. (1-800-635-9781)

I've never priced them anywhere else. Let us know what you find.

 

[Chris McDade]

Hey guys I found the ESC from the dealer for $66.18.
List was $88.25 with my Houston Buick Club discount 20%.
It's around $66.00.

I will let you know if it fixes the problem.

Thanks again guys