Hehehe.... Them rascally sensors.

Wait a tick, why do I have to drain the coolant anyway?

KR sensors just go into the block, so..... :?:

It might go in and have a water jacket cooling it. Just a thought...prolly the wrong thought...lol

Yup, according to the FSM, there'* a water jacket there. Too bad noone has any idea how much coolant would drain out when you pull the sensor. Might save a little money if it'* just a tiny bit....

The sensors are installed in holes normally used as freeze plugs. They use the acoustics of the coolant (water) to 'listen' to the block. It helps them detect the sound of knock.

Ok...(celebrating having been right once!) how low is that freeze plug? I'm assuming it'* right on down there at the very bottom like a FP should be. You could try the super secret vacuum hose trick but I'm betting you wanna use something a little quicker.

????? They're in freeze plug THREADED holes, but there are no plugs. The sensors come installed from the factory.

The 2 knock sensors are mounted in the middle of the block on each side, inline with cylinders 3 and 5. There is a boss in the block with the sensore mounting into them vertically into threaded holes which open into the water jackets. You're baet to access them both from underneath.

You will need to drain almost all the coolant or will get it all over the place once the sensor(*) are out. If you're running Dexcool you'll likely have sluge builup against the sensor in the water jacket, be sure to clean this before reassembly. Each sensor has a connector with 1 wire attached, the sensors ground through the block so use a thread sealant rather than Teflon tape to reassemble.

If you're concerned about KR and its origins, there is a way to check to see if it'* false or not without disassembling anything. Go find yourself some 104 octane or higher gas and put in about 10 gallons. Be sure you're nearly empty before filling. Do some driving on the high octane gas in mixed driving, some 'spirited' runs but not aggressive until you burned a few gallons. Once this is done scan the car on a WOT run from a standing start into 3 rd gear. Be sure to find an appropriate place to do this. Be sure to pay attention to the scanner while doing this and back off if you see excessive KR.

If your KR is cured with high octane gas then the knock is likely real and you should find the source. If it is not cured, then most likely something is loose and causing the knock sensors to react.

What are your O2 readings at when you experience the KR?

Keep us posted!

Cheers,

I never drained my coolant when replacing a knock sensor. The coolant barely trickles out. Not much comes out so I never bothered to drain the coolant..

That means you had a lot of sluge built up around the sensor. If you did not remove that before reassembly then your sensors were not as effective as they should have been, it'* like having ear muffs on.

Cheers,