Cars throwing a knock code, drives fine nO knock, some times feels a little boggy, but the code comes on and off randomly? Bad sensor?

 

Clutch or trans work done lately?

 

If it's feeling "off" to you, I'd be worried. Could be anything as insignificant as a wiring problem throwing a bad code to a major mechanical malfunction. I'd go easy on her till you get everything checked out. As a technician, I can say the most accurate problem detector is the driver, and If they tell me the car's driving is "off", then I take that very seriously...

 

...but if the code comes on intermittently, I'd bet that either:

1.) your "bad sensor" assumption is correct
2.) one of your exhaust or intake valves is "slapping". This is usually only an issue in cars that have been enthusiast-owned and usually take place after a lot of time has been spent in the higher RPM ranges. Your intake valves open to deliver the proper air-fuel ratio into your combustion chamber. The valve then shuts and the sparkplug ignites the mixture while the piston compresses the mixture. The resulting 'explosion' sends the piston hurtling down again, therefore transferring power to your camshaft. This is the point where the camshaft converts it into rotational energ, yada yada yada. After combustion, the exhaust valve opens, and all the 'used' gasses are pushed out of the cylinder by the piston's return stroke. At this point, the 4-stroke cycle restarts. An easy way to memorize it? Suck, Squeeze, Bang, Blow.

After so long, the valves can become weakened or worn to the point that they fall low enough when opened to be hit by the piston. This could generate enough resistance/interference in the cylinder to throw a knock code, even though your engine isn't really 'knocking'.

 

I have to completely disagree with the above statement.

 

that sounds really bad, but if you catch it early, all you're going to need is a new valve and maybe a new valve guide. These are pretty inexpensive, but shops will charge a lot because you have to remove the cylinder head in order to get to all the valves. That usually takes a lot of service hours unless the tech is really knowledgeable. You don't usually need to worry about the piston itself, as Honda is veryyyy particular about the composition of the piston heads. You'd have to drive hundreds of miles on it before you'd typically see a piston fail due to "slapping". Since you'd already be in the area, if you're interested in performance, you could always replace everything with forged parts? This is usually only done to track cars, as it's fairly expensive. But the new internals can take an INSANE amount of abuse...just something to think about

 

Billman, I would've said the same thing a year ago if I didn't see it firsthand...the kid brought in a 2001 S2K throwing a knock code due to...slapping. We resurfaced the valve faces and replaced the broken valve and....voila, no more knock code. I know it sounds crazy, but it DOES happen...

 

My money is on the sensor, the connector is probably broken.

Its bogging because its probably loading up with fuel

 

I put new plugs in and it runs tons better therefore loading with fuel is logical. Ive owned the car for two years almost it has seen small amount of nitrous, 5k miles of boost and a clutch job, I'm really thinking its a bad connector the car has no knock and runs good. I know this from using the microphone knock detector tool (unsure of name) but my bet is just bad sensor, I do have 122k on the car and did a valve job back 3 months ago from recieving misfire codes fixed that and have had no issues untill recently. Is tere any write ups for knock sensor replacement. Thanks everyone for feedback

 

Not really a write up. I can tell you how to do it though.

You will need a 24mm socket. Its pretty cut and dry, just real tight quarters.

Jack the car up, its underneath the center of the intake manifold. You can really only see it with a flashlight, and the rest will be all feel. Reach in and unplug the sensor, then snake your 24mm socket with a ratchet (Bonus points if you have a swivel or a flex head ratchet). Put it over the sensor and unscrew. It may be kind of tight but thats all there is to it.

If you pull up a parts diagram on majestic honda, you can see exactly where it is. Like I said its in the Center, directly underneath the intake manifold. The whole thing for me was the FEEL. I could barely see the sensor at all but I could feel exactly where it was.


Just take your time and don't get frustrated.