Knocking sound when turning left or engine over 3,500 RPM, left-front wheel!

[IBx1]

Hey everyone, we just bought an '04 Outback LL Bean edition with the flat-six. It has 117,000 miles and it's a gem, but the one problem with the car is this fast knocking sound from the front-driver's side wheel. At almost any speed above 10mph it makes this relatively fast knocking/popping sound while turning left, but it also happens when the engine goes over 3,500RPM in any gear when going straight down the road.

Any clues? CV joint, sway bar link, tie rod end? I'm mechanically inclined so I'll understand technical replies.

Thanks!

[barkeater]

disconnect the swaybar link and if you still hear then that ain't it. Really, your best bet is to first find out where it is coming from. See the squeak/rattle link and answer each of the questions as best you can, like does it happen while braking, etc. Put car up on jack stand and see if you have any play in the wheel (top/bottom or side/side). Take wheel off and look around for any evidence of anything loose, (i.e., brake components, etc.). Up front you have a lot more things to check than in back but by process of elimination you should be able to narrow it down. Good luck

[1 Lucky Texan]

cv related seems most likely. bad joint or axle not fully seated in diff.

I wouldn't discount wheel bearing. Soobs have odd wheel bearing symptoms at times.

if it seems related to road surface, it might be suspension...

[IBx1]

Originally Posted by barkeater

disconnect the swaybar link and if you still hear then that ain't it. Really, your best bet is to first find out where it is coming from. See the squeak/rattle link and answer each of the questions as best you can, like does it happen while braking, etc. Put car up on jack stand and see if you have any play in the wheel (top/bottom or side/side). Take wheel off and look around for any evidence of anything loose, (i.e., brake components, etc.). Up front you have a lot more things to check than in back but by process of elimination you should be able to narrow it down. Good luck

How do I disconnect the sway bar linkage? I haven't been under the car yet but if anyone has pictures of exactly what to look for, that would be awesome. I'm hoping it's that because they're a lot cheaper than half-shafts and bearings. I'll have to wait a while to jack the car up since I left my jack and stands up at school when I came home for Thanksgiving, but I plan on seeing if the wheel wiggles too much like that.

How many lb-ft do I torque the lug nuts to, by the way?

Originally Posted by 1 Lucky Texan

cv related seems most likely. bad joint or axle not fully seated in diff.

I wouldn't discount wheel bearing. Soobs have odd wheel bearing symptoms at times.

if it seems related to road surface, it might be suspension...

It's independent of how smooth or potholed the road is, and the suspension feels very competent otherwise. I don't think it's a bad shock or spring at the moment.

[1 Lucky Texan]

lugnuts are around 80 ftlbs I think.

EMPI axles are only about 10-$15 more than (generally) crappy rebuilts from local car parts stores. RockAuto has good prices on EMPI. Yeah, they're chinese, but most people have good service from them. properly case hardened new units that are better than re-ground rebuilts. You may discover a split cv boot. Unless you KNOW it has recently split, that joint would be suspect due to being exposed to grit/water from the road.

[cardoc]

Originally Posted by IBx1

Hey everyone, we just bought an '04 Outback LL Bean edition with the flat-six. It has 117,000 miles and it's a gem, but the one problem with the car is this fast knocking sound from the front-driver's side wheel. At almost any speed above 10mph it makes this relatively fast knocking/popping sound while turning left, but it also happens when the engine goes over 3,500RPM in any gear when going straight down the road.

Any clues? CV joint, sway bar link, tie rod end? I'm mechanically inclined so I'll understand technical replies.

Thanks!

According to what you posted, you either have a lifter issue which is making the noise and you think its from the wheel, when its actually internal to the engine and the design of the engine and where it sits in the engine compartment makes it appear to come from the wheel. Or, you have 2 different problems with the second being a bad axle.

A bad axle will make noise when turning when it develops enough wear that the joints pop.

The lifters will make a knocking noise with engine acceleration regardless of driving or not.

If it makes the knock at 3500 in park, you can narrow it down, at the next oil change, or change it now, by poring in a bottle of Lucas oil treatment for the last quart, it holds 6, and run it at idle for about 10 minutes and see if it still makes the noise. And you can do this without driving the car. Just have it sit in park and rev the engine to the rpm level it makes the knock. If the knock goes away, it has a lifter leaking down that will need to be replaced.

If it only makes the noise while driving, it may not be associated with engine rpm at all, but related only to the drivetrain, suspension or steering.

[IBx1]

Doesn't happen when parked and the engine is revved up, so no lifter problem! Thank god...

[cardoc]

If you can get a recording of the noise and post in relation to the engine/transmission operation, it may be easier to determine the issue. If I hear it, I'll know what it is.

The turning effect seems like a CV axle. Its the 3500 rpm that is leading me to think you have 2 separate issues.