P1000 Knocking in engine?

[Cowman]

Don't think it is hangers or mounts...this sound is too rpm specific - not periodic and irregualar....and is very predictable under what circumstances it occurs under. As I said previoiusly, the noise is restricted to about 2500 - 3000 rpm under load. Above or below that rpm range no unusual noise. No unusual sounds after cranking cold until that rpm range is reached. And the noise tends to go away after the engine is thoroughly warmed up...that would not be explained by loose hangers or mounts. have pretty much isolated the noise to the intake area. Removing the filter, one can hear it pretty plainly through the two intake ports. This noise gradually appeared beginning about five months ago. Before that no unusual noise in engine at any time.

I did go over the exhaust stystem feeling for leaks especailly around where others suggested I focus...even burned my hand on one the the headers near the engine. I can find no leaks. It doesn't mean this is not an exhaust sound, but I have not been successful in isolating any leak, and I am a pretty good mechanical troubleshooter.

Not giving up.

 

[Admin]

 

[Cowman]

I have a follow up to all this...I have found the problem...and the solution. 😄

I kept thinking this sounded like intake noise, because as I had previously stated, after removing the filter form the filter box, I could hold a piece of hose to my ear with the other end near the intake openings leading to the throttle bodies and that seemed to be the source of the sound. I have been busy, but today I found time to reinvestigate.

I again removed the filter but this time, I removed the entire filter box. That is when I discovered that the air intake tube connecting the filter box to the throttle body port nearest the front of the engine was partly cracked around. It finished breaking completely as I took the filter box off. I ordered a new filter tube and then using heavy duty duck tape, I repaired the old filter tube and put everything back in place. getting those air tubes into the filter box and onto the throttle body is a hassle. Anyway, when I got it all back together I crossed my fingers, cranked the engine and ...no unusal noise, she purrs like a kitten! It sounds like it did originally, so I am confident the source of the noise was a leak in the air tube and that I now have it whipped. The problem was not exhaust noise. I will install the new air intake tube when it arrives. Thanks to all for your comments.

Happy camper!!! 😁

 

[DRZRon1]

thanks for the follow up- good deal

 

[NTCPrezJB]

I have a follow up to all this...I have found the problem...and the solution. 😄

I kept thinking this sounded like intake noise, because as I had previously stated, after removing the filter form the filter box, I could hold a piece of hose to my ear with the other end near the intake openings leading to the throttle bodies and that seemed to be the source of the sound. I have been busy, but today I found time to reinvestigate.

I again removed the filter but this time, I removed the entire filter box. That is when I discovered that the air intake tube connecting the filter box to the throttle body port nearest the front of the engine was partly cracked around. It finished breaking completely as I took the filter box off. I ordered a new filter tube and then using heavy duty duck tape, I repaired the old filter tube and put everything back in place. getting those air tubes into the filter box and onto the throttle body is a hassle. Anyway, when I got it all back together I crossed my fingers, cranked the engine and ...no unusal noise, she purrs like a kitten! It sounds like it did originally, so I am confident the source of the noise was a leak in the air tube and that I now have it whipped. The problem was not exhaust noise. I will install the new air intake tube when it arrives. Thanks to all for your comments.

Happy camper!!! 😁

Good find. Hopefully it didn’t pull a bunch of dirt through the motor.

 

[Cowman]

There was a very small amount of dust trace inside the tube at the break but I don't think there was enough to cause any appreciable damage.