This is a continuation of this thread->http://www.ultimatesubaru.org/forum/showthread.php?t=57733.

 

Here is a link to the knocking sound I cannot shake on my 2.2L rebuild.

http://media.putfile.com/Knocking-Subaru-Engine-22L

 

It is similar sound to a large extent as the racket heard on this site:

http://www.lovehorsepower.com/SubaruDocs/LashAdjusterReplace.htm

 

I've found one lazy HLA on the left side. I also found a loose rocker shaft bolt on the rocker assembly on the right side. After replacing the HLA and tightening the rocker shaft bolt, I still could not get rid of that sound.

 

I swear the sound is down low.....the sound clip above is recorded from BENEATH the oil pan. But it can clearly be heard from the top center of the engine above the throttle body.

 

Running out of ideas.....might tear apart the right side rocker train again to see if there was any collateral damage from that loose rocker shaft bolt.

 

Any suggestions?

Auto or manual tranny? Sometimes the auto tranny flexplates will crack, and a knocking sound will be heard. People buy the replacement engine, take the old one out, and then notice the flexplate is cracked.

that's a pretty good sound byte, and from what i am hearing it sounds like piston slap(piston rocking back and forth in cylinder)

thats NOT a good noise. Pull one plug wire at a time and see if the sound goes away or changes pitch. Lets start there. The fact that it comes and goes is puzzling. Its not a lifter noise, and yes you can hear the injectors but thats not it too.

If this is is an automatic, what condition is the flex plate in?

 

nipper

thats NOT a good noise. Pull one plug wire at a time and see if the sound goes away or changes pitch. Lets start there. The fact that it comes and goes is puzzling. Its not a lifter noise, and yes you can hear the injectors but thats not it too.

If this is is an automatic, what condition is the flex plate in?

nipper

 

I need to try the spark plug test.

 

This is an automatic trans car. The flex plate was in good working order at installation - nice ring when you strike it. So no cracks at that point. Visually I cannot see anything like a crack.....but the only part I cannot see in where the bolts hold the plate to the crankshaft. Not looking forward to pulling an engine again, but this may be unavaoidable.

 

Other background noise is the injectors and a noisy "rolling" sound from the alternator bearing. But that knock is quite distinct and different.

Hmm... I wish I could hear you rev it.

 

I was gonna say rod knock, but the rare occasion that I've heard a Subaru with a rod knock, it's always been continuous and doesn't fade in and out like that.

 

What about the main bearings?

main bearings would be constant too. If it goes away by pulling wires, its rod, if not, its a main bearing

 

nipper

I couldn't get the sound click to work, but I may have some info that will help you. I have an older Chevy 4x4 that had a distinct knocking sound coming from the engine that I could NOT get rid of. When I finally tracked it down, it was actually a small crack in the bottom of my exhaust manifold. Even a badly mated manifold to exhaust can cause the sound as well as I found out once I pulled the manifold and replaced it, then didn't fit the exhaust perfectly back to it.

 

GOOD LUCK!

I know that this may not be relevant, but, I had a dodge caravan (honest - its the wife's car) where the flexplate was not cracked, but improperly torqued. As the car transitioned from driving the transmission to being a "brake" on the transmission, the bolt holes elongated - the flexplate would actually rotate around the crank and cause a tapping sound similar to what I heard on the clip - somtimes...

 

HTH,

Keith

i keep forgetting it can be an exhaust leak. the exhaust maniolds are so simple i forget that possability.

 

nipper

Main bearings will make more noise on a cold start than when it is warm, on the other hand a loose rod will make more noise at a steady throttle at one given rpm. Try to listen real hard on a cold start, if its not any different i would guess it is a flex plate noise. ed

The way it sounds, and the fact it comes and goes would rule out exhaust leak IMO.

 

It does almost sound like piston slap.

Totally away from the internals and the fact it comes and goes, I have had more than 1 timing belt tensioner cause a sound just like this. To rule it out, just remove the left front (drivers side) timing belt cover and start the engine. I use a piece of heater hose to my ear and the other right by the opening to the pulley to listen. Also on some you can look in far enought to see the belt and pulley bouncing at the time of the noise.

 

Rule it out before you start removing the engine and tearing it down.

yes i also agree...i think its either a tensioner or pulley in the timing line up...i had that same noise on my 93 imp and then a month later it got worse and decided to break....i ghad to have the toothed gear replaced

I appreciate the suggestions. Really want this motor to work right.

 

So I'll test running the motor with the driveplate disconnected from the torque converter - maybe this will reveal something if there is a problem with the plate.

 

I also think that is a good idea to check out the tensioner with the left side timing belt cover removed. I'll give that a shot.

 

This is a more recent recording of the mysterious sound.

http://media.putfile.com/20060614-Subaru-22L-knocking-sound-2

I appreciate the suggestions. Really want this motor to work right.

 

So I'll test running the motor with the driveplate disconnected from the torque converter - maybe this will reveal something if there is a problem with the plate.

 

I also think that is a good idea to check out the tensioner with the left side timing belt cover removed. I'll give that a shot.

 

This is a more recent recording of the mysterious sound.

http://media.putfile.com/20060614-Subaru-22L-knocking-sound-2

 

thats an ugly noise. Its def something in the timing belts. Can be the tensioner, can be an idler, either way its better that you findo out before the car shows you for itself what it is.

 

nipper

 

PS sound file helped alot, wish more people would do that

So I'll test running the motor with the driveplate disconnected from the torque converter.

 

Bah, forgot about the starter being on the torque converter side.

 

I rotated the drive plate 180 degree on the torque converter to see if placement changed anything and with two bolts only in case the plate was warped. The plate rings perfectly clear like a bell - so I've pretty much ruled that out.

 

I looked at the tensioner as much as it can be seen with that part of the belt cover removed. No other spinning object that I can currently see rotates as fast as the rate of the knock. Difficult to associate the revs of the tensioner pulley to the knock....but it could be I suppose since it is smaller diameter. Cam pulleys don't turn anywhere near that fast.

 

And now that I think about it, there are 3 other pulleys besides the tensioner under the timing cover are in there. This picture is from an oil seal replacement on the old engine.....

Yeesh....that means one of 4 spinning things in there could be making that racket (assuming internals are fine). I hate the idea of going all the way back in there on my new engine.

 

Pffft....need to go to bed.:-\

That is a very confusing noise. Is the noise louder when its cold or is always constant.

Moms 01 Forest made some funky noises when you gave it more then slow gas pedal pressure. n e ways sounded like lifters or spark knock.

 

New plugs and wires made it go away.

Also made the exhaust leak quiet down.

 

mileage is way up and its super smooth and quiet.

 

Yeesh....that means one of 4 spinning things in there could be making that racket (assuming internals are fine). I hate the idea of going all the way back in there on my new engine.

 

Pffft....need to go to bed.:-\

 

 

normencalture.. they are spinning thingies

 

nipper

Well I finished my investigation of the timing pulleys and concluded that all is well on that end of the motor. There is one idler pulley (lower right) that drags a little, but does not have play. I assembled everything without the timing belt covers and ran the engine.....the knocking sound is still there. And it is not coming from the front of the engine - it is loudest under the oil pan.

 

Since everything is operational and I haven't thrown a rod by now, the car is back in service. It is a little unnerving - but I run airconditioning and some music and I'll try it for a while. If it really gets to me, then I will pull the engine again and double check the drive plate.

 

Thanks for the suggestions so far guys.

JPX,

 

Did you ever resolve this knock? This sounds exactly like what I have had for at least 2 years and 18k miles now with my 96 2.5L.

 

Thanks

John

The noise sounds like lifter noise to me, they probably

need adjusting.

 

Richard

The knocking sound hasn't really gone away. :-\

 

I need to record another round of it to compare between then and now to see what is different.

 

And since the valve lash adjusters are hydraulic, there is nothing to adjust other than making sure they hold firm after pumping up with oil. And they all checked out following the replacement of a single dead one.

Thats a connecting rod, it doesnt tick fast enough to be a valve noise, and its too deep in the engine. There is not enough mass in the valve drive train to creat that sound, thats a very mean ugly rod knock (take from somone who threw a rod through the side of his engine)

 

nipper