Installed a few mods: LS6 intake, headers, !air, !EGR, plugs, wires

Had the car tuned the other day and it has a horrible knock, usually above 5k rpms but occasionally knocks randomly while under 50%+ throttle. I did not replace the knock sensors when I did the intake install. When it knocks it pulls 2 degrees of timing from the engine and does not throw a code.

Thinking about swapping the knock sensors to see if that fixes the problem, but they'd throw a code if they were bad right?

Anybody else had this problem? Any suggestions appreciated!

Jeff

 

The would throw a code if they were bad. Describe this knock.

 

Check all your plugs and make sure they are tight!!

Also check and make sure all your header bolts are tight also.

 

I can't actually hear the knock over the exhaust. But the engine is pulling 2 degrees when it happens, usually at 5k+ at WOT

Already done. Everything there is good.

 

If you cant hear it then there is no actual detonation because you can hear it over the exhaust if it is happening. What is going on is that the sensors are picking up detonation and are pulling a little timing to prevent the motor from getting detonation. the knock sensors are doing their job. I would suggest starting out by replacing your fuel filter and spark plugs if you havent done it in a while. You could very well simply be leaning out on the top end too much, which causes detonation. It could also be false knock coming from the exhaust pipes as well.

FWIW, i was getting knock before and it was my clogged fuel filter. 5$ fix and 10 minutes.

 

Get the car on a scanner that shows what its doing. Like Hptuners or something and see what the timing is doing. If all plugs and wires are fairly new and look decent then it is prob in the tune . IMO I wouldn't be running the car to much if it is something more serious.