Ever heard this noise?

Maybe someone here has heard this noise before. My shop suggested sending the oil out for analyzing, but the car would sit about a week until the results come back, instead I contacted Subaru for more info and they got me an appointment tomorrow morning.

Any information is better than what I have now Ive spent some time searching the forum and youtube but I came up empty handed.

A little history of the car,

It is a 2006 Outback XT 5MT

First owner was SOA corporate in Colorado for 1 year ending odometer 38,962miles

Second owner was an individual in Pennsylvania for 9 years ending odometer 102,250

I took ownership a month and a half ago with no maintenance records.

First thing I did was Timing belt water pump and power steering. A week or so later did both lower ball joints as the boots were torn. About a week later I really started to notice a clicking in the front right, turns out the front passenger axel had excessive play laterally and was clicking only when accelerating on a turn so it was replaced with a heavy duty replacement.

Now this odd noise on startup...

I took the time to record the noise anytime I would start the car, I tried to note if the car was reading warm or cold but it only happens on the first start up and for no more than 2 seconds as shown by the attached video link.

Say I start the car and the noise happens, if I were to turn it off and back on again no noise would be present on startup.

Hope this helps and yall can guide me through this.

https://youtu.be/yiI00WmZwXQ

Sincerely,

Zack

When you did the timing belt service, did you replace just the belt, or did you also replace the tensioner, idlers and water pump?

Your symptoms sound a lot like a bad timing belt tensioner.

The belt and pump were done but not the tensioners or idlers. Correct me if I'm wrong but if it were the tensioner or idlers a noise would be present for more than for 2 seconds immediately after starting, majority of the time on cold start.

You can see for yourself if you remove the right timing belt cover, get a flashlight and observe the tensioner while someone else starts the car up with the engine cold.

It is important to replace the tensioner and idlers when you do the timing belt service. These are wear items and they often fail before the timing belt does. This means, at best, having to do the job over again, or at worst, expensive engine damage.

I just received a call back from the shop, he confirmed the tensioner and idlers were replaced as a part of the Gates timing belt and water pump kit.

back to the drawing board....

When I dropped it off at Subaru this morning, the tech said it may be a bearing or something to do with oil pressure during initial startup.

How valuable would an oil analysis be at this point?

...the Gates timing belt and water pump kit...

Another thing that might help is to use a mechanic's stethoscope to see if it's possible to narrow down where the noise is coming from.

I can see where the shop is coming from with low oil pressure at startup, but bearing knocking noise does not usually just go completely away after a few seconds. You would expect it to get louder when the engine is under load. It'll be interesting to see what they find.

Gates tensioner = bad

I had the same problem with my last 2 Gates tensioners, but worse. It went away after an hour or two of engine operation.

I'd put my money on it being the tensioner. I wonder if the shop bled the new tensioner like gates says to. The tensioner might bleed itself over time, but I hope the belt doesn't jump before that happens.

https://www.gates.com/~/media/files/gates/automotive/resources/tech-tips-and-tsbs/gates-bulletin-pa002_16.pdf

https://uploads.tapatalk-cdn.com/20170323/e008024efe41840c096ea6bbd1dc2c74.jpg

Subaru just called and quoted me 1300 for an engine tear down. The technician is suggesting the noise is originating from a half spun bearing.

Thoughts?

Subaru just called and quoted me 1300 for an engine tear down. The technician is suggesting the noise is originating from a half spun bearing.

 

Thoughts?

If you had a bearing going bad, the noise doesn't normally go away completely. The noise would get louder as the engine is under load. Do these sound anything like your issue?

I called Subaru back to suggest that it is the tensioner.

As a matter of fact I have a video of cold start from 2 days before the invoice for the timing belt and the only noise I hear on startup was power steering belt squeaking.

I really do hope that it is the tensioner.

That # will climb fast if They tear it down and it's still the timing tensioner.

No, not at all.

Those examples are of a constant noise not one that goes away shortly after startup.

But since the tensioner is always running as the engine idles not sure how that would be a 2 second noise then go away.

That is $1300 to tear the engine down to diagnose what is wrong? Probably quite a lot more to repair it, like $4000+.

 

If you had a bearing going bad, the noise doesn't normally go away completely. The noise would get louder as the engine is under load. Do these sound anything like your issue?

 

 

 

 

I contacted IAG Performance and they confirm Subaru's suspicion based on the YouTube clip attached.

" Unfortunately that sounds like rod knock caused by a spun bearing. It

sounds worse after sitting due to the lower oil pressure. I wouldn't

recommend running the motor at all, as you could be pumping bearing material

and risking further damage."

Ouch.

So IAG Stage 2 Tuff is ordered already?

Order me one too!

I'm good for it.

Check the tensioner before you go block shopping. I have had this happen before, and when I did my timing belt with new Aisin tensioner, the sound went away. That was over 9,000 miles ago. If it was a spun bearing there's no way my car would still be running.

Edit, I've had two used oil analysis run since then as well, both of which indicated my engine internals were in great shape, and to push out my oil change interval to 7500 miles. Do a UOA if you want to be certain it's not internal, otherwise just make sure your oil is topped off and check that tensioner.

Could you assist me with some links or guide me through what steps to check the tensioner? I have done the needful and maybe im not searching the right keywords but I was unable to find something worthwhile in the forum or on google.

I really doubt that's rod knock... I think you need to check everything else like everyone keeps telling you.

Assuming things are generally the same on the turbos as my non turbo, you'll have to remove your two accessory belts from the front of the engine, you'll have to remove the crankshaft pulley, and you'll have to remove the timing belt covers. I'm thinking that when you first start your car, there isn't enough pressure for the pin to keep tension on the belt, so the tensioner bounces up and down, creating a knocking sound. After pumping up and down a for a few seconds, pressure builds, and the tensioner can keep pressure on the belt, and the knocking sound goes away.

This is what you don't want to see.

If you remove the tensioner from the car, you shouldn't remove the tensioner first, there's too much tension on the bolt that holds it in if you do that.

This is a non turbo motor, but this explains what I said above.

failed timing belt tensioner with motor running.

random youtube video of a dohc subaru timing belt replacement

Ill Check it with my own eyes when I get it back, but I am still skeptical because those examples show the noise happening non stop and continuing to increase with acceleration also its less similar in sound. The key to my issue is that it only occurs for 2 seconds then goes away completely. To my ear there is no noise at all through acceleration. If the engine is turned off after a cold start immediately, then turned back on, the noise will not return, which leads me to the believe it is an internal issue. Not the timing belt tensioner.

While Subaru still has the car while the airbag recall is being done, I am thoroughly enjoying their 2018 Forester loaner. The Eyesight, lane departure, and adaptive cruise control are fantastic features. I also really enjoy the ease of use on the touch nav and phone integration.

I think the difference is that your tensioner is not 100% bad, if that were the case, you would hear the noise all the time like in one of the videos.

I think your tensioner was not bled of air as instructed by gates. So that's why the problem only occurs for a short time. It's probably a good tensioner, just has air in it.

Ill Check it with my own eyes when I get it back, but I am still skeptical because those examples show the noise happening non stop and continuing to increase with acceleration also its less similar in sound. The key to my issue is that it only occurs for 2 seconds then goes away completely...

Thank you for your knowledge and patience.

Please do check it for yourself, then you won't have to be skeptical anymore. You will know for sure, one way or another, and we won't have to argue with you any further.