soft knock front of engine (video)? 2004 2.5XT

amorgan93 · 10-10-2012, 11:14 AM

There is this soft knocking from front my 2004 forester xt. Can be heard best at around 1200 rpm, I had a weight on the gas pedal holding it at the exact rpm where it can be heard best. No noises in higher rpm, can faintly be heard between idle and 1500rpm. I dont think its pronounced enough to be a big end failure, its a somewhat softer knocking noise. Also, the noise remains even with the accessory belts removed. Any ideas of what it could be?

any help is appreciated!
thanks!

Soft knock from front of subaru. 2004 forester xt - YouTube

Youtube video of STI with bad belt tensioner. Sounds kinda similar doesnt it? The engines in both videos are even spinning the same rpm.

Subaru STi rod knock, piston slap, spun bearing, belt tensioner - YouTube

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chris@grimmspeed · 10-10-2012, 05:23 PM

That could be a very good possibility. I would check it asap brfore it has a chance to get worse.

stevejones19 · 10-11-2012, 02:38 PM

I am no expert on this, but I have had the same noise for quite awhile. I just ordered a new timing belt kit, and hoping that will take care of it. I could only reasonably believe it to be the tensioner in my case. The 2 stages my car has been through were tuned by very reputable tuners, and fluids were checked very regularly, so I doubt (more wishful thinking) that i'm having a knock.

What are your miles/mods?

Uncle Scotty · 10-11-2012, 03:11 PM

rod knock and a failing timing belt tensioner sound very similar

rod knock is usually apparent at higher rpm

what oil...EXACTLY....is in it

teiva-boy · 10-11-2012, 03:26 PM

being a 2004, when was the timing belt and other items changed as part of your normally scheduled maintenance?

stevejones19 · 10-11-2012, 08:01 PM

Quote:

Originally Posted by Uncle Scotty

rod knock and a failing timing belt tensioner sound very similar

rod knock is usually apparent at higher rpm

what oil...EXACTLY....is in it

This really good news on my end then, glad I saw this.

amorgan93 · 10-12-2012, 01:34 PM

I run rotella t6 5w-40. The timing belt and head gaskets were supposedly done at 124k according to the place I bought it from. I bought the car at 130k. There is evidence that someone has been under the hood, the plastic timing cover has a chip about the size of a quarter missing out of it, right under the crank sensor. I question if they just replaced the belt instead of all the pulleys, etc..

My car is cobb OTS stage 2, with a catless uppipe, invidia catless downpipe, and 05 sti catback. Have an 09 sti tmic sittin in the garage, hoping to go stage 3 soon.

stevejones19 · 10-12-2012, 04:42 PM

Yes some people try to skimp and save money. Just re-using the tensioner and not touching the water pump or idler pulleys.

JayDavies15 · 10-13-2012, 10:00 AM

Needs a timing belt tensioner. Id do the water pump and pulleys too. Gates makes a kit that you can buy on extremepsi.com for around $300.

amorgan93 · 10-13-2012, 11:36 AM

Yep was looking at the complete timing belt by gates, seems that it has good reviews amongst other subaru owners. What's not fun is timing a 2.5 DOHC, and I've never timed one that has AVCS, I don't know if that makes a difference or not.

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10-10-2012, 05:23 PM	#2
chris@grimmspeed Scooby Specialist Member#: 301037 Join Date: Nov 2011 Vehicle: 2003 & 2006 WRX WRB & OBP	That could be a very good possibility. I would check it asap brfore it has a chance to get worse.

10-11-2012, 02:38 PM	#3
stevejones19 Scooby Specialist Member#: 275250 Join Date: Feb 2011 Chapter/Region: NWIC Location: Lacey, WA Vehicle: 2006 WRX White	I am no expert on this, but I have had the same noise for quite awhile. I just ordered a new timing belt kit, and hoping that will take care of it. I could only reasonably believe it to be the tensioner in my case. The 2 stages my car has been through were tuned by very reputable tuners, and fluids were checked very regularly, so I doubt (more wishful thinking) that i'm having a knock. What are your miles/mods?

10-11-2012, 03:11 PM	#4
Uncle Scotty Scooby Guru Member#: 16200 Join Date: Mar 2002 Vehicle: OK Houston we have an Uncle	rod knock and a failing timing belt tensioner sound very similar rod knock is usually apparent at higher rpm what oil...EXACTLY....is in it

10-11-2012, 03:26 PM	#5
teiva-boy Scooby Guru Member#: 22825 Join Date: Aug 2002 Chapter/Region: NWIC Location: Seattle, WA	being a 2004, when was the timing belt and other items changed as part of your normally scheduled maintenance?

10-12-2012, 01:34 PM	#7
amorgan93 Scooby Newbie Member#: 267563 Join Date: Dec 2010 Vehicle: 2004 Forester XT Silver	I run rotella t6 5w-40. The timing belt and head gaskets were supposedly done at 124k according to the place I bought it from. I bought the car at 130k. There is evidence that someone has been under the hood, the plastic timing cover has a chip about the size of a quarter missing out of it, right under the crank sensor. I question if they just replaced the belt instead of all the pulleys, etc.. My car is cobb OTS stage 2, with a catless uppipe, invidia catless downpipe, and 05 sti catback. Have an 09 sti tmic sittin in the garage, hoping to go stage 3 soon.

10-12-2012, 04:42 PM	#8
stevejones19 Scooby Specialist Member#: 275250 Join Date: Feb 2011 Chapter/Region: NWIC Location: Lacey, WA Vehicle: 2006 WRX White	Yes some people try to skimp and save money. Just re-using the tensioner and not touching the water pump or idler pulleys.

10-13-2012, 10:00 AM	#9
JayDavies15 Scooby Newbie Member#: 298486 Join Date: Oct 2011 Chapter/Region: NESIC Location: Plymouth, MA Vehicle: 2006 Impreza WRX Black	Needs a timing belt tensioner. Id do the water pump and pulleys too. Gates makes a kit that you can buy on extremepsi.com for around $300.

10-13-2012, 11:36 AM	#10
amorgan93 Scooby Newbie Member#: 267563 Join Date: Dec 2010 Vehicle: 2004 Forester XT Silver	Yep was looking at the complete timing belt by gates, seems that it has good reviews amongst other subaru owners. What's not fun is timing a 2.5 DOHC, and I've never timed one that has AVCS, I don't know if that makes a difference or not.