Knock Sensor

[jgentry]

I have a 6.0L 2500HD 2001 Chevy truck. I'm getting the check engine light with a knock sensor code showing up.

Just curious what the cheapest remedy for this would be? Do I go to the dealer? Do junk yards have these type of things?

Thanks!

-Jonathan

[DmaxMaverick]

Welcome aboard!

First, clear the code and watch for it to return, and when. Most of the time, it's just a glitch or one-time event. "Cheap" gas can also cause knock problems. You may try some fuel additive labeled to "reduce engine knock". That's it for the "cheap remedy".

If the DTC continues, check the air/fuel filters, spark plugs/wires. A plugged air or fuel filter can cause fueling fluctuations, leading to an actual knock, as can poor plugs or wires (mice like the taste of ign wires). If you have over 100K on it, replace all 4 items anyway.

If all checks out and the DTC continues, the sensor is about $40 at Autozone, and no more difficult to replace than any other sensor (like oil pressure, ECT, etc.).

[jgentry]

Thanks alot for the advice. That's a big help!

I cleared the code several times and it comes right back. I was thinking based on how quickly it comes back that it may be due to the sensor going bad. After all the truck has nearly 200K miles on it.

I'll follow your steps anyway as I think it may need a tune up.

-Jonathan

[DmaxMaverick]

With 200K on it, the complete tune-up would be the first thing I'd do. Late model gas engines are miles ahead of the older engines (prior to OBD II). I've seen some of them run well, then suddenly just fall flat, only to find spark plugs so used up the electrodes were not even there any more, and ign wires turn to dust when you touch them. I think we've become spoiled with the later technology, and have forgotten that 25-50K miles was the standard for complete tune-ups, and 100K on an engine was over-the-hill, not long ago.

[Mark Rinker]

Yeah, back in the 'carb kit', 'points/distributor cap/coil', 'set the dwell', 'gap the plug' days! LOL