[Mitch T.]

This problem occurs after the engine is warm and I can hear it on passenger side under the timing chain cover. Accelerates with engine speed but seems to go away at driving speeds. Is there a common problem here with timing chain or something else that could cause this?
It doesn't seem to be coming from valve cover area.
Thanks.

 

[cardoc]

The 3.0 chain system is designed to last a very long time and a large number of miles. (100s of thousands) Ticking after the engine warms up is an indication that it is viscosity or flow related.

Has the oil maintenance been on time and proper viscosity used?

Does it have adequate oil now?

How long has it been doing it?

Unfortunately, there is no way to know what is worn or damaged without removing the front cover.

 

[1 Lucky Texan]

seems like anything under the tc cover would make a zipper noise - not a ticking noise. Of course, could be tensioner related but, if you see what I mean, the main moving parts are chains - how could they make a regular, discrete tick?

I assume it's a regular tick and not a buzz like heat shields could make. Not a whine from the power steering which is nearby, not a failing serpentine pulley - each of them fail with some regularity.

a stethoscope might help pin the sound down.

 

[idosubaru]

it's not the power steering pump or heat shields is it?

does the noise change with oil changes?

the guides are known to occasionally cause noise. mine was making noise when i bought it at 130,000 miles and it now has 201,000 and i've never addressed it. i haven't heard of a tensioner making noise yet but it is surely possible.

there are a couple of folks that have taken the covers off and shown some great pictures and details here. i'd look for those pictures and see if you can isolate the noise and if it's a guide or tensioner. i'd be inclined to escalate the repair if it's a tensioner, where a guide i wouldn't worry about nearly as much.

 

[TheGeologist]

I have a similar ticking sound from my '02 H6 OB. Its at a constant interval and very discrete. However, this is a constant sound--its there regardless of engine temperature and increases in frequency with higher RPM's. I haven't really given it much thought because my timing chain assembly is in good condition. Thoughts?

 

[1 Lucky Texan]

what mileage is on these cars? some folks say the valves need adjustment at 200K or more, others have reported problems with carbon buildup apparently interfering with valve closure but, these reports aren't very consistent/widespread.

the other noise sources mentioned ARE known issues and should be completely ruled out before further testing or disassembly is undertaken. measuring oil pressure is probably a good next step I'd guess.

 

[Mitch T.]

From Mitch T.

Oil is fine, viscosity is fine, heat shields are fine, power steering is fine.
We bought the car with 54K on it and noticed a slight ticking after a couple thousand miles. Now it has 85K on it and ticking getting louder when warm but goes away with acceleration. If there is a tensioner in the area or guide then that is what it probably is. But I didn't buy a Subaru to have to pull of the timing chain cover at this point to fix something that should be good for 200K.
Groosgary you are probably right and I will have to look for the pictures and waiting for warm weather in April to tear this thing apart.
A good engine diagram on this site would be helpful.

 

[Glennda5id]

I think it may be difficult to rule out valve noise especially if its coming from cylinder 1 which is passenger front. The sound may transfer to the timing cover. Have you tried using a stethescope on the valve covers?

The valve lash should be inspected every 100k miles or so I believe. While your car only has 85k miles on it it is still 10 years old. Many short driving cylces can lead to carbon build up which could cause your valves lash to loosen up and cause ticking.

As someone who has had to deal with the timing chain issue, this does not sound like a timing chain issue, but its difficult to say without seeing it.

I find the injectors to be pretty noise on these vehicles as well, although not usually noticeable during driving.

I personally would pull the valve cover and check the valve lash before doing anything else.

 

[147_Grain]

I find the injectors to be pretty noise on these vehicles as well, although not usually noticeable during driving.

This is most likely the source of the ticking sound. Not a big issue. Fuel injector cleaner will help, but not totally solve the ticking noise.

 

[idosubaru]

*** everyone with H6 ticking should also be inspecting (actually they should be even without ticking!) the serpentine belt bearings - tensioenr and idler pulley. massive issue and there's a sticky about it.

always rule that out first if you have noises in the front of an H6 engine.

can you record/post the sound?

These engines generally run a long time with noisy timing gear. Got mine at 130k and it now has 201k and it's had the same loud timing chain noise on downshifts since day one. And I've heard that story multiple times before so the chain guides/tensioners are somewhat robust. I'm sure it's happened but I haven't heard of a timing chain failure yet...if it's happened it is extremely rare even on the boards. I'm not worried about it, but then again I have a whole fleet of cars and can fix it so easy for me to say.