I have this metal on metal ish clunking sound on idle. It is a EURO 2009 outback 2.5 (EJ253) with LPG conversion. At the moment of filming it was running on gasoline but also when warm the same sound persists only on idle when not in gear (in gear the rpm level is higher) when I throttle up it is gone and comes back when rpm drop to idle again. Oil level was fine though needs replacing. I really sounds from the front, and both serpentine belts look fine. Car has almost 100k miles and last valve adjustment was 25k miles ago and is advised to do so again. Also spark plugs were replaced 25k miles ago.

 

 

 

Hope someone recognises it.

kinda sounds like loose timing belt tensioner. Piston slap is possible I guess, but that's usually reported in older model year cars.

 

you a re very near needing to service that system (if you are reporting miles and not k'meters - 105K miles is the maintenance schedule)

 

compare to this video

 

 

skip to about 4:30

 

 

Not in Europe we do the same but than in km, so timing belt was serviced at 105K km (about 50K km ago).

But it indeed sounds a bit like that though mine goes away with rmp increase.

 

kinda sounds like loose timing belt tensioner. Piston slap is possible I guess, but that's usually reported in older model year cars.

you a re very near needing to service that system (if you are reporting miles and not k'meters - 105K miles is the maintenance schedule)

compare to this video

Edited January 28, 20179 yr by rverdoold

Could also  be noisy tappets.

First thing to try is to do an oil+filter change.

This sometimes works.

Hate to say it but that sounds like the beginnings of a rod knock.

 

Check the timing tensioner and idlers for play just to be sure.

definitely a metal to metal sound. Perhaps a bad bearing in the alternator. In this situation, it is nice to have a mechanics stethoscope . It looks just like what a medical doctor uses to check your heart. Only difference on the mechanics stethoscope, on the business end is a short rod of metal. Put the ear pieces on your head, then touch the metal rod to what might be making the noise. Once you find the source, you will hear it loud and clear in your ears. This tool is available at parts stores.

Was going to check the alternator, should be easy by removing the belt. Is that bearing replaceable?

Indeed either alternator or ps pump. The alternator runs ok with no noticeable play in pulley, however the ps-pump has back and forward play in the pulley and imaginable torsional play. I reinstallEd the belt with somewhat less tension and noise is less. Are both bearings serviceable?

Just to be safe, you can turn the car on with the ps belt off and if the noise is gone then you know for sure what the issue is. You could have it rebuilt if there's someone local but I would just replace.

That is what I did too. Without belt the noise is completely gone. Will rebuild the alternator bearing and brush. Those seem easy. The ps pump bearings seems harder.as it is differently mounted but haven't looked carefully to those diagrams yet.