Jump to content
Please check your junk folder for registration emails ×

Timing Belt Tensioner the cause of this noise?


Recommended Posts

So my new WRX is making a lot of noise specifically on Passenger side of engine. I took it to Subaru mechanic for them to hear it and they said could be valve clearance or buggered piston.

I decided to try a few things before pulling the motor including applying pressure to the belt tensioner. As you can hear the sound goes away but I do have to apply a decent amount of pressure. I also notice the timing may be off by a tooth (although sometimes they 'look' out but are actually correct). The noise goes away when I apply pressure to the tensioner so it would rule out possible piston/valvetrain isues which means there is a timing or tensioner/idler issue correct? 

Interested to know if anyone has had something similar before.

 

The timing components are all from Japan and I can still see some of the yellow lines on the belt. Belt kit was done about 65000kms ago (unless there was one done since with no proof)

 Pictures of timing and video of noise below.

 

20210617_21451320210617_21460620210617_214552

 

Link to comment
Share on other sites

The timing belt being off by one tooth with not make a noise... the engine just won't run quite right.

 

But the exhaust wheel fouling on the intake wheel will likely cause a bit of a noise... as in the last picture.

  • Like 1
Link to comment
Share on other sites

2 minutes ago, Loren said:

The timing belt being off by one tooth with not make a noise... the engine just won't run quite right.

 

But the exhaust wheel fouling on the intake wheel will likely cause a bit of a noise... as in the last picture.

I talked to Alastair at Macbilt again and he confirmed it was off by a tooth and the belt was likley changed without a new tensioner or idlers. He said a new timing belt kit will likley fix it noise.

It definitly feels slow to boost and low power down low due to timing being out.

 

I don't think the exhaust wheels is fouling on the intake wheel, just looks like it due to the angle of photo. I'll double check that later tho.

Link to comment
Share on other sites

4 minutes ago, Subru said:

I talked to Alastair at Macbilt again and he confirmed it was off by a tooth and the belt was likley changed without a new tensioner or idlers. He said a new timing belt kit will likley fix it noise.

It definitly feels slow to boost and low power down low due to timing being out.

 

I don't disagree with any of that... I just don't think that noise would be caused by the belt being out by one tooth. I certainly WOULD be changing the belt, tensioner, all the idlers and water pump though.

 

 

4 minutes ago, Subru said:

I don't think the exhaust wheels is fouling on the intake wheel, just looks like it due to the angle of photo. I'll double check that later tho.

 

Link to comment
Share on other sites

4 minutes ago, Loren said:

 

I don't disagree with any of that... I just don't think that noise would be caused by the belt being out by one tooth. I certainly WOULD be changing the belt, tensioner, all the idlers and water pump though.

 

 

 

Yeah I agree, being out a tooth will only effect performance and wouldnt cause this noise.

If the tensioner is stuffed however, it can cause that noise (not sure how exactly). There are videos on YouTube that does similar thing to mine. The fact that it stops when I apply pressure tell me it must be a timing component so I will get new gear and hope that it fixes it. 🙂

Link to comment
Share on other sites

Usually you would have a belt guard above the crank pulley to prevent the belt from jumping... is it just off for checking the position of the belt, or is it missing?

Link to comment
Share on other sites

2 minutes ago, Loren said:

Usually you would have a belt guard above the crank pulley to prevent the belt from jumping... is it just off for checking the position of the belt, or is it missing?

Nope it was missing, good spotting. I did notice that but didn't think it was super important. I think I'll try find one before I put it back together.

Link to comment
Share on other sites

yeah they are important... once you find one, make sure the spacing is correct... too big of a gap and it won't prevent a jump... too small and heat builds up and damages the belt.

 

Edited by Loren
  • Thanks 1
Link to comment
Share on other sites

 

I installed new timing belt kit, water pump etc and it still makes the noise. I did notice when the cambelt was off that when I spin the passenger side intake cam anticlockwise it makes a clicking noise in the head when it starts to engage the valve bucket. It doesn't make the noise if I spin it clockwise (when it hits the other cylinder valve buckets) or with driver side intake cam. That tells me its probably a valve clearance issue after all and that its specifically the intake cam on passenger side of engine one one cylinder (someone can probably tell me what cylinder it is too). 

I'll continue to pull the motor and take off rocker cover and see what clearances are. Ill have to buy some feels gauges first...

 

Edit: if it makes a difference, this already has a second hand engine with avcs running on a non avcs ecu. I doubt they swapped everything to make avcs work when they'll did the swap years ago. So maybe that could be causing some issues?

Link to comment
Share on other sites

I tracked down the possible noise to the passenger side intake cam gear (avcs cam but not running avcs due to ecu being for a non avcs motor). The cam gear appears to have just a small amount of play which makes a clicking noise when I spin it back and forward. When I take the cam gear off and spin the cam with my fingers, the clicking noise goes away. I may find a second hand non-avcs intake cam gear and (hopefully its compatible with the cam) and see if that helps.

Im just not 100% sure if this cam gear clicking noise is the same noise as what im hearing when the engine is running, I thinking it probably is tho.

 

Link to comment
Share on other sites

7 minutes ago, Loren said:

I'm no AVCS expert but I know it's operated via oil pressure... maybe it needs some constant oil pressure to take up some slack in it's mechanism?

That's definitly a possibility. I'm going to talk to the guy from MacBilt again and see what he thinks.

May need to get a new cam and cam gear if that's the case as I think the non avcs gear won't fit onto the cam correctly 

Link to comment
Share on other sites

Valve clearances are roughly within spec. All intake clearances are 0.007 (0.168mm) except one is 0.008 (0.203mm) and one 0.009 (0.229mm). Those two are on the noisy side of the engine but I doubt are out enough to cause this noise.

 

Exhaust clearances are all 0.009(0.229mm) or 0.01 (0.254mm) except two are a tad small at 0.007 (0.168mm). Also on the noisy side of engine but doubt these are causing the noise.

 

After a second inspection there definitly is play in the avcs cam pulley (where oil pressure moves it normally but is currently dry) gonna pickup another avcs cam pulley one tomorrow and hopefully that one is good. This explains why the noise stops when I put pressure on the timing belt tensioner, maybe it puts enough pressure on the cam pulley to prevent it from clunking around.

Link to comment
Share on other sites

Motor is back in and running mint. The cam gear was the issue because they were AVCS cams but with no oil pressure running to them (running on a non avcs ecu and the oil lines are blocked off). I was very close to thinking I needed a new motor, glad I found it was an easy fix. The engine was put in back in 2013 so they lasted a long time so im not worried about it becoming an issue again for a years.

 

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share



×
×
  • Create New...