Hi guys, I finally got data logging working, and am seeing a constant error code of my knock sensor not working, despite the light not coming on. I've done some digging around, and it looks like I have a sensor on the lower back of the passanger side block with the connector broken off of it. I'm guessing this would be my knock sensor, but I've also read here that 2.8l engines did not have a knock sensor?

 

they do and that's it, well try hooking that connector up and do ur data logging again and see what happens.

 

Thanks, i'm going to have to try an get a replacement connector, the entire plastic part of it seems to be shattared and broken half onto the sensor, half onto the connector.

 

2.8's do not have knock sensors.

If this sensor in the block or the bottom of the passenger side head? THere should be nothing in the block over there, but the one in the head has a green wire going to it and is the fan override switch.

 

Its in the block, far back passenger side. A bit under all the EGR junk, and very difficult to really see or reach. I really need a good book to this car, does the GM shop manual cover in detail what sensors are on which year/engine combinations and so forth? The Haynes book is pretty useless in this fashion.

 

Is this what your referring to, just above the starter.....

 

That looks like a knock sensor alright, but yours is a 3.1L, right?

 

That's what I was getting at. If the original poster was referring to the sensor in the pic that I provided, then it's more than likely somebody swapped engines, and/or blocks....

 

What I am seeing looks pretty much identical to this image.


There is also a single plug type connector that seems like it would fit this sensor, that has a single blue wire running back into the wiring harness.

The only major difference between the pic, and the sensor/plug/etc that I see is that mine has a much narrower plugin connector that is all metal, my guess would be that there may have been a plastic piece around this part of it that also is broken off.

 

If you look in the picture I provided, you will see the same exact sensor right above the starter, on the bottom of the block....

 

Yes, I see that accept I think mine is a bit broken. However, this isn't suppose to exist on a 2.8 right? I guess I really don't know that someone hasn't swapped motors in it, though there are black gm valve covers with bright red 2.8 sticker on it, and the plenum has 2.8 marked on the top (would these swap over to a 3.1 block? )

 

Yup....

I recently found 2.8 exhaust manifolds on my '92 3.1. It happens....

 

Okay well, I'd gladdy accept having a 3.1 vs a 2.8, but I would like to know if this is indeed the case or not. Is there any way to verify what the block is without needing to find casting numbers on it? If I need to find numbers, where should I be looking? As my worthless repair manual doesn't talk about 3.1 v6 engines at all it seems.