Motor mounts and knock?

[BARRACUDA1968]

I have been wondering if I'm dealing with real knock or false knock.

I did a 3rd gear pull tonight and watched the WB, I never saw anything over 10.5. I had 2.1 knock at 79 mph. 02 was 765 on the scanmaster

I have 2.8 degree of timing out of the TT chip, boost at 23 psi and alky on 6. Fuel at chip settings.

I sometimes get weird knock numbers that don't seem to make sense. I checked my down pipe and it is close to the frame but I figured with the red poly motor mounts I have the engine wouldn't move enough to make contact. I felt the pipe where it could hit the frame and I don't think it's hitting.

I wondering if the poly engine mounts are part of the problem? Could they be translating vibration more than a stock mount?

 

[KEVINS]

Anything is possible. I went through this same question this fall with my stock mounts and I decided to see if different mounts would change it. Instead of poly mounts I just welded up the stockers so they were completely solid. It didn't help a bit so I cut the braces back off and it's still the same.

ks

 

[Chuck Leeper]

Knock sensor torque is?

 

[BARRACUDA1968]

I haven't checked that yet but was just wondering if anyone else had anomalies with these mounts.

 

[Heisenberg]

Check your downpipe where it runs over the passenger side upper A-arm.
When people look for DP rubbing on the frame, they usually don't see anything.
But if you slip your DP off - and slide it out - you might see where it is rubbing the A-arm (towards the rear of the car)
I know I did.

I use the term "false knock" as well.
But as has been pointed out to me - there is no such thing.
The ESC is triggering from something.
True enough - I usually didn't hear typical engine knock - but in the heat of tires screeching and engine revving - it's hard.
I never assume KR to be false - and conduct myself accordingly..

 

[BARRACUDA1968]

I checked the A arm and I have almost 3 inches clearance so I should be good there. I am however real close to the frame.

I never hear and audible knock but I agree you should treat it like it's real until proven otherwise.

Just seems strange to have knock with my readings. I've always had unexplained knock with this car I'll just keep it in the safe zone and keep looking for a reason.

 

[BARRACUDA1968]

Going to re-torque the sensor since I didn't put it in.

 

[BARRACUDA1968]

Here's what I found. I went in the shop and grabbed ahold of the knock sensor and I swore it turned with my fingers. I couldn't see real well but it sure looked like it did so not knowing for sure how to remove it etc I call Dave Husek and he explained it to me. While on the phone with Dave I tried to turn it again and it didn't turn. I was actually disappointed because I was looking for the smoking gun on my knock issue.

I decided to remove it anyway and re-torque it. After getting everything out of the way and getting the connector off I put the socket on the knock sensor with an extension and it turned loose in my hand.

At least now I know that I'm not delusional, it was definitely loose! I removed it from the car and it has the red material on the threads so I'm thinking it hasn't been removed or messed with since 2004 when the motor was rebuilt. I'm going to email the previous owner and see if he ever messed with it because he bought the car right after it was restored. He also had some issues with weird knock numbers during the time he owned it. I actually looked through old threads on this board from him talking about it.

My question now is should I just buy a new one or reinstall this one?

 

[KEVINS]

It seems to be working I'd reinstall it. You can always replace it later and see if a new one operates any differently for a comparison.

ks

 

[Chuck Leeper]

No teflon tape, nor any other material, is needed on the threads. Clean the block threads, the sensor threads, and torque to 14 #/ft. Check the connector for corrosion, tight fit.

 

[BARRACUDA1968]

No teflon tape, nor any other material, is needed on the threads. Clean the block threads, the sensor threads, and torque to 14 #/ft. Check the connector for corrosion, tight fit.

The sensor has red material on the threads, it looks like something the manufacturer put on the threads. You want me to remove it?

I am waiting to borrow my friends snap on TQ wrench to reinstall it. I know it's accurate.

I will make sure to check all the rest of your suggestions.

 

[BARRACUDA1968]

Reinstalled the sensor and took it for a drive. No knock in 3rd gear pull like before.

Nailed it in 1st and ran through the gears, had 19.9 knock?

I torqued it to 14 ft pounds but just never felt I had a good reading on the tq wrench. Every time I checked the TQ with the wrench it turned a little more.

 

[MDavis]

Did you ever figure this out? I'm suspect poly mounts in my situation also.

 

[BARRACUDA1968]

Yeah I figured it out. The motor was junk. Rod and crank bearings were gone. I have a new motor now and no KR so it isn't the mounts in my case.