Rod Knock on my high mileage 2.2? Video!!

[harrymaneuvers]

Ok... So I just got back from a 1200 mile round trip and noticed a noise that I wanted some clarification on. I will try my best to explain it.

While cruising down the hiway at 70 mph, radio off (I cant hear it with my radio blasting), under acceleration I hear nothing... When I let my foot off the gas, I hear nothing, But if I lift my foot off of the acceleration and let the car start to slow, then I push the accelerator so that the car maintains speed but doesn't feel like it is increasing in speed, It sounds like a VERY fast knocking... Very fast... and in conjunction with the engine. If you have heard what a woodpecker sounds like, it is very similar but faster.

I would almost compare it to the way a "Jake Brake" or engine brake sounds. Or even like someone who rolls their R's when saying spanish words... but keep rolling the R for like 4 seconds. Go ahead and do it outlound... right now.


As soon as I press on the gas enough to start increasing in speed, it goes away... Only if I let up off of acceleration and then press on the accelerator enough to just maintain the speed...

It is almost like if the engine is loaded either with acceleration or deceleration it doesn't make a sound... but as soon as it is neither accelerating or decelerating... it makes that sound.


Piston slap? I hear the noise for about the first 3 seconds or a cold morning start up as well...

All help is appreciated.

[Looselugs]

Worn prop shaft joints will cause loaded/unloaded noises. Hopefully not a front differential failure.

[harrymaneuvers]

That is what I was hoping... besides the prop shaft coupler... where would the next likely suspect be???

[loganmossmusic]

I get that same sound. Its tends to do for the first 30 or so minutes of operation, and I would assume that a 1200 mile trip took longer than that. I always assumed it was piston slap. The fact that you dont get it at all must be pretty nice, it gets annoying. If its not piston slap I gotta go with worn joints. Was the back of your car at a different height than the front? That would put an angle on the driveshaft, making the joint have to work at an angle, which could cause that sound.

[harrymaneuvers]

Ok so post from the dead... I got my car smogged last week (passed) and the tech and I both noticed the sound when he reved up over 2500 RMP...

Here is a video I just took today. I would say I am probably reving to about 3k max... No CEL... great gas mileage still.

https://sl-i.net/FORUM/images/imported/2011/12/th_DSCF0211-1.jpg (http://s773.photobucket.com/albums/yy18/harrymaneuvers/?action=view&current=DSCF0211.mp4)

[eltrd]

I have the same problem its driving me nuts !

[Baddog]

Sounds like a lifter

[harrymaneuvers]

Wohoo!!!!!!! Right?

[Baddog]

easy enough fix. what oil are you using? low oil?

[harrymaneuvers]

Well it is a phase 2 2.2 so I am pretty sure it has solid valve adjusters and not the hydraulic ones of the phase 1.

I am running AMSOIL 5w30... just did an oil change 3 weeks ago.

[Baddog]

Was this a cold start?

[harrymaneuvers]

no... car was fully heated up then sat for maybe 20 minutes before restarting it and taking the video.


Even if the car was at regular temp, the sound is still there are RPM's about 2400

[Baddog]

My engine has been doing this for awhile. Tried different weights. I have a feeling its lifter noise. As it goes away at higher revs.

If you stick your head under the engine while its running it sounds like its coming from down there. Who knows. Mine has been fine just a little noisey. ANd sometimes it doesn't even do it.

[harrymaneuvers]

Yea I am thinking it is lifter noise too... I would think that if it was rod knock or piston slap, it would be there at almost all rpm's... my car idles and runs great, it is just loud at certain harmonic RPM's...


Anybody have experience with adjusting the lifters on a phase II 2.2L? I just did the valve cover gaskets too :smt021

[harrymaneuvers]

Bad news... I dropped off the ladies wrx wagon to FW motorsports to tweak the custom tune on it because I was getting some pretty bad boost oscillation.

FW motorsports is essentially THE subaru shop in Northern California.

I decided to let Paul (the head tech and owner) have a listen.

He can pretty much guarantee that the noise is rod knock... Although it doesnt really scare me because I have had this rod knock for over 30k miles... It does motivate me to start building a spare/back up engine...


LET THE NEW THREAD BEGIN!!!

viewtopic.php?f=11&t=23349 (https://sl-i.net/FORUM/viewtopic.php?f=11&t=23349)

[r3v_v3ng3]

My friends car was making somewhat the same noise like that. His turned out to be the idler bearings for the timing belt but it was already too late. Ball bearings exploded out of it and messed up his motor. So I hope you guys have done the timing belt and changed all the bearings/tensioner with it.

[harrymaneuvers]

Yea I can tell you that it is not the bearings or anything related to timing belt... I just did a timing belt job about 20k miles ago and the sound is coming from the center/passanger side of the engine... deep inside the engine.

[r3v_v3ng3]

His #1 rod bearing was also spun so i don't know if that was caused by the timing catastrophe or they both happen at the same time :smt017