Engine knock questions...........................

[builds4christ]

Hey all,

Could use some ideas on finding the reason for my engine knock. Pretty sure their erroneous because she runs beautifully and isn't noisy in a detonation sort of way.

I've been trying to get the truck tuned, but they keep having to pull timing for KR.

I found a spot on the chassis where the exhaust was hitting and fixed that only to find that it didn't fix the KR issue.

I don't have any KR codes. Do you think the sensors might be bad?

It's a Procharged setup too and has some janky routing going on for the intake piping (previous owner of course), lol.

If y'all have had any funny stuff happen I your trucks that caused a similar issue, please share!

Thanks so much y'all!

 

[Marky Dissod]

When the tuner has to pull timing for knock, how much timing is the tune pulling? And does it pull the same amount of timing (or more) after the tune is REadjusted?
If that's the case, start looking for physical/mechanical causes of false knock.
Do you get knock in Neutral, just revving? Again, if you get that same amount of knock retard (or more), look for other physical/mechanical causes of false knock.
Might be worth it to throw a pair of knock sensors at it, but before you do, try several comprehensive wire bending/wiggling tests.

 

[builds4christ]

When the tuner has to pull timing for knock, how much timing is the tune pulling? And does it pull the same amount of timing (or more) after the tune is REadjusted?
If that's the case, start looking for physical/mechanical causes of false knock.
Do you get knock in Neutral, just revving? Again, if you get that same amount of knock retard (or more), look for other physical/mechanical causes of false knock.
Might be worth it to throw a pair of knock sensors at it, but before you do, try several comprehensive wire bending/wiggling tests.

Hey Marky,

I'm getting some new sensors in today through summit. Good idea to check knock in neutral.

With the baseline tune, the truck was a beast, but on 3 subsequent tunes, it became less and less powerful because of timing, but I'm not sure how much he's pulling, exactly. The thing went from throwing you back into your seat to feeling like it's old and tired.

The tuner thinks it's erroneous and asked me to inspect everything.

I'm going to try logging KR in neutral and see what I get. Man what a pain

 

[mikez71]

I had severe knock retard once because I didn't tighten one of my motor mounts..
It didn't happen right away, but later after some bolts backed out..

It sure sounds like false knock, good luck with finding it.

 

[builds4christ]

Thanks Mike!

I'll check them out. I think I used blue loctite on the bolts for the engine mounts, but not the tranny mount.