My '01 H6 Outback has 99k on the odo and will often have a sort of loud rattling/vibration type noise near the front of the engine on start up that goes away after a few seconds. It's fairly loud. I've never changed out the timing belt. Any clues as to what I'm hearing? Is it possibly a timing belt tension issue, or maybe time for a new belt? Thanks.

The H6 has a timing CHAIN, not a belt. Replacing the timing chain is not inexpensive. It would be unusual to have to replace the timing chain under 100,000 miles. Have the engine inspected. Excessive rattling noises is one sign of a worn timing chain. It might just be the chain giudes. Failing to regularly change the engine oil is the most common cause of premature timing chain wear.

rattling is really common and can be a number of things. exhaust heat shields are most common and can vary, have those inspected.

 

oil level and changes are very important on this vehicle with it's timing chain set up. like he said, no belt.

 

if it is the engine then it's your timing chain guides probably and that is a rather large job but it's roughly the cost of a timing belt job so not the end of the world either. mine has a light whine when i floor it. it isn't likely to cause issue (i didn't say that it *can't*), mine has been that way for about 30,000 miles since i got it and no doubt for awhile before that.

I remember but can not find now something about bad chain guides. This is not an impossible job to do, and may be easier to set the timing then a belt. That said, there are literally 105 bolts to hold on the cover. There may be a gasket I dont know. If you keep track of what bolt cam from where it is fairly straight forward. I bet a guide is worn, and these guides are like rubbing blocks.

 

http://www.endwrench.com/current/summer03/H-4.pdf

 

Forget what I said about straight forward. It is also not a cheap job to do. I would ask an area service rep about it.

Edited July 27, 201015 yr by nipper

The trouble may just be due to bad idler pulley bearings. You have the right kind of mileage for that kind of thing.

Lets back up a bit. Remove the serpitine baelt and see if it goes away. There have been a few issues with the serpitine pully.