Nautique Knox Sensor problem

[cacman]

I have a 2007 Nautique PCM Magnum330 every time at 34.2 mph by 3 or 4 ball engine light comes on and screen reads knox sensor see dealer, goes out when you throttle down. Boat seems to be running ok. With zero off off I can run up and down lake at full throttle, light never comes on. Also pulled neighbor at 32 light never came on. Spoke with a guy from local marine he said that indicated sensor was bad, and it was intermittent. But every time at the exact same place in course is not intermittent. He thought but did not seem sure that once light goes on you have to reset code, but light is not always on. Any thoughts. Thanks

[oldjeep]

Bad tank of gas (under octane), and you are actually getting a knock? How long has the problem existed?

[oldjeep]

Could also just be detecting a misfire due to worn out cap/rotor/plugs/wires

[cacman]

Was ok last season. Just put boat in a week ago. Have added gas.

[oldjeep]

Have you also checked to see if the knock sensor(s) are loose? Not sure what kind they use on a 2007 GM marine engine, but on my 2012 there are 2 that are on studs that gets removed to drain the block when you winterize - possible that they just didn't tighten the nut down enough.

[Jody_Seal]

Did someone put tef tape or sealant on the knock sensor threads?

[oldjeep]

@Jody_Seal - do you know which style knock sensor a 2007 has?

[Jody_Seal]

a round one?????

[oldjeep]

LOL, more wondering if it is like this - old one piece style

http://www.nautiqueparts.com/images/products/detail/R020027.jpg

or this - separate stud and sensor

 

 

 

[Jordan]

It could be the sensor itself that's faulty....you might also want to check that the electrical connector is on tight.

[Mateo_Vargas]

@oldjeep it's the 1st picture, one on each side.

[Mateo_Vargas]

@Jody_Seal what's the proper method to seal (no pun intended) a knock sensor?

[Jody_Seal]

R020027 , The round one!

[Jordan]

Your knock sensor doesn't need any additional sealant...it has a tapered thread that will seal just fine on its' own.

[oldjeep]

I don't use any sealant, but I do use copper anti seize on them. Not worried about leaking, getting them out in one piece is another story.

[Jody_Seal]

No sealant there is already a patch lock on the threads. don't use a pair of pliers to install but rather a socket and don't over tighten.

[cacman]

Knox sensor looks like the first picture. Our boat has a closed cooling system so we did not take them out when we winterized. I pulled both connectors off and cleaned with some contact cleaner. Any great way to test sensor. Also I would think if sensor faulty it would continually give error code.

[oldjeep]

Given that you haven't touched them and it worked fine last year. I'd toss in a bunch of premium gas and run it to see if the problem goes away.

[dbutcher]

I had a 2007 PCM Excalibur 330 that did the same thing at 4 ball. It turned out that when I had the ECM reflashed at a local ZO parent company location for the installation of ZO, something didn't go right. One or more of the ECM readings were outside PCM parameters. I sent the ECM to PCM for reflashing. When I got it back, the problem was gone. I have a friend whose 09 check engine light came on sporadically, That turned out to be the wire between the knock sensor and whereever it goes (probably the ECM). Reportedly PCM had to manufacture the replacement wire because that style isn't currently used.

[mwetskier]

just in case you have an extra fitting you havent mentioned -you can not have any fitting between the knock sensor and the block. we tried several ways to draw hot water from the block drain plug hole using t fittings and such but the sensor always ' failed '. the local nautique guys -pacific nautique over in auburn wa -told us that wouldnt work and they were right so we ended up pulling hot water from another point on the block.

[JBskilot]

cacman, I have a 2007 Nautique with the same symptom: check engine light...knox sensor...only with ZO on and around the 3 or 4 ball. It only happens once every 5 or ten sets. Did you ever find a solution? I think it's been about 3 or 4 years since my ZO was updated to the latest firmware.

[FLeboeuf]

I had knock sensors codes twice this year. First time it was not tight enough with thread sealant..not good. Second time the rotor was loose and cam retard was off 4 degrees. Now it should be good hopefully. I have a ex343 2011.