Knock Sensor

[rollingthunder1994]

Hey Everyone,

I hope you all are well. Does anyone have a diagram where the knock sensor is located on my 94 STS? My check engine light came on, the codes i pulled said my Knock Sensor is bad

[Ranger]

I would not swear to it but I think it is under the intake manifold, in the valley.

[adallak]

I would not even try to replace it. Does the engine knock?

[Cadillac Jim]

If you don't have a working knock sensor, the PCM will put you on a spark advance curve that protects the engine as much as possible but you will take a noticeable hit in gas mileage and performance. That mode is there to keep you on the road until you can get it fixed. If you're not comfortable doing it yourself, you should get it done ASAP.

Yes, it is in the cylinder valley, below the intake manifold. The intake manifold is held by four small torque-and-twist bolts, and the dealer parts guy tells me that the gasket is re-usable. You get to it by removing the four bolts from the top noise/heat cover. There are electrical connectors and fuel lines on the top of the intake manifold and you need to be careful to disturb them as little as possible when you pull the bolts and pop up the intake manifold.

You then disconnect the knock sensor, unscrew it, screw the new one down and toque to to 14 foot-pounds, put the connector on, and button it up.

What was the code, exactly?

[Cadillac Jim]

... The intake manifold is held by four small torque-and-twist bolts, a

That's ten (10) torque-and-twist bolts total, including four studs that also hold the heat/shound shield over the top of the engine. See factory manual, pages 6-50 through 53. For removal only, see pages 6-102 and 103. They say only to torqe them to 10 N-m (89 in-lb) when the engine is cold.

The fuel lines, EGR hoses, and such are listed in the process of removing and replacing the intake manifold. You can probably just loosen it and pop it up a little to get at the knock sensor. It's likely you won't have to disconnect the fuel lines and such, at least not completely. Anyone have experience with this? If you've changed a battery cable or knock sensor, you've done this.

[jfreezn]

Hey Everyone,

I hope you all are well. Does anyone have a diagram where the knock sensor is located on my 94 STS? My check engine light came on, the codes i pulled said my Knock Sensor is bad

I believe you will find the knock sensor on the firewall side of the block, just towards the passenger side. It looks like a mechanical mushroom, about 1 1/2" accross the top. Should just screw out, but the exhaust manifold kind of obscures the area.

Jim in Phoenix

[KHE]

The '93/'94 engines had the intake fastened with four bolts - the inner four bolts that are visible when looking at the top of the engine. When the plastic intake with separate beauty cover was implemented for the '95+ engines, 10 bolts were used to retain the manifold along with the 4 acorn nuts that retain the beauty cover.

[Poobah]

Before you begin taking the intake manifold off, look on the firewall side of the engine toward the right side of the car. You should see the knock sensor directly below the ignition coils. It's a tight space back there and there's lots of stuff in the way but you should be able to see it there.