Auxiliary / Serpentine Belt Tensioner

[flakeypaul]

I've noticed a loud whirring noise developing coming from the cam belt end of my engine (2003 S80 2.0t) when I'm driving. I'm pretty sure it's not the turbo (CBV operates but the whirring continues).

I've done a quick visual check and I can see that the auxiliary belt tensioner is slightly wobbly when the engine is running. With the engine off I am able to rock the plastic pulley slightly.

I'm assuming the tensioner is shot and I've ordered a new belt & tensioner from Volvo, but does anyone know if this is a sign of a worn/failing pulley or whether a little play is normal?

[Brendan W]

There is a little play in them when new with the belt off. Unfortunately 'little' is not a well defined term. There should not be a visible wobble running and for that reason I would think you have found a culprit , assuming only one.
I would suggest that you run the motor briefly with the belt off to eliminate anything on the timing belt side ( unlikely) and then check all the pulleys on the aux belt,

[oragex]

As above, you may remove the auxiliary belt and run the engine for less than a minute (so as to not discharge the battery) and listen.

Or with the belt in place you can also use - carefully around rotating belt and pulleys - a 1ft. flexible plastic pipe to listen near the pulleys when the engine is running as well. It is important to rule out either auxiliary or cambelt pulleys about to freeze as if they fail they can damage the engine (and chirping might mean a pulley is about to fail)

[flakeypaul]

Thanks guys,

First step will definitely be to get the belt off and have a listen - I've got a replacement belt and tensioner on hand to get the job done in one go if the tensioner turns out to be the culprit. Have to say whilst the new tensioner does have a tiny amount of play in it it's nothing like the play on the pulley fitted to the car (probably a good millimetre of 'wobble' when it's running).

I cannot see the aux belt having ever being replaced in the part history I have, so either way probably worth fitting both parts even if they're not the culprit. Looks like Volvo have changed the design, the one on my car can be de-tensioned using a 14mm spanner, the replacement needs a huge torn bit. There goes another £10.

The timing belt (and pulleys - a kit was fitted at a volvo specialist according to the service history) is 4 years and 70,000 miles old so technically not in need of replacement yet according to the book but definitely on the to do list (as soon as we get a nice day).

Hopefully the aux belt and tensioner will sort it but I'll report back here whatever happens. Really hoping the snow holds off at the weekend!

[D5meister]

dont buy the full tensioner - just replace the black INA pulley on the tensioner £17

[flakeypaul]

Well the whine got louder still today. The car is now parked up outside and will be started up tomorrow minus its aux belt - hopefully the noise will go away.

The only concern I have now is that the sound is much louder and seems now to be coming from the other end of the engine i.e. the gearbox, which would obviously be quite bad!

[Brendan W]

See what the morrow brings. Human ears aren't the greatest of instruments. Hopefully the noise goes away with the aux belt removed.

[flakeypaul]

Thankfully removing the auxiliary belt brought total peace and quiet (and a lot of warnings on the dashboard).

Removed the old tensioner (which had a loose top bolt) which was a bit of a pig of a job due to my shovel like hands and penchent for dropping sockets but straightforward enough (two bolts). Took me a while to figure out how to get it out from under the car (can't be lifted out from above due to other pulleys).

Actual pulley wheel was clicking when span and had a lot of movement. The tensioner could also be operated by hand (unlike my new one) so it looks like it was well and truly past its best.

Unfortunately the new tensioner came without a 14mm bolt so a trip to Halfords was needed to get a 60mm torx bit.

Refitting the tensioner was a reverse of removal - there's nothing to hold it in place so it's just a case of locating the top bolt and pivoting to locate the bottom bolt. Not a lot of room and much more easily done from under the car (although I did not have to jack it up or remove the wheel.

New belt went on fairly easily once the wife got her head around how it fitted. Using the 60mm tore bit to release the tensioner, it actually fouls the belt when not under tension, so you have to counter-intuitively wrap the belt over the socket to get it to work (pain in the back side).

Took it for a 15 mile test drive and it's like a different car! So quiet now I can actually hear the CBV when I lift off.

Next job - ATF change. Checked it yesterday and its not pretty.