Walking timing belt

[darrylrobert]

So i always thought the "washing machine" noise from my 2001 xc70 2.4t engine was my coolant pump, on closer inspection i can see the timing belt "walking" side to side on the idler pully. I have bought a new Volvo pump and timing belt kit.

I find the Haynes desciption of tensioning the idler puller rather confusing, am i tensioning it wrong? or is this walking normal??

Also do i need to remove the crankshaft pulley or can i squeeze it past like i did my 1998 p1 v70???

walking timing belt 2001 xc70 2.4t

walking belt.png (617.18 KiB) Viewed 2678 times

[- Pete -]

Just so we, and anyone who reads this in the future, are clear, the tensioner is circled in red. Don’t take that the wrong way, just trying to help out respectfully. Also, it looks, to me, like your tensioner may be set too tight, but I have no idea what the temp was at the time the photo was taken.

The idler is circled in yellow.

The tension on the tensioner needs to be set according to engine temp (cool, ambient). Use your 6mm Allen to hold the tensioner eccentric while you snug down the hex farstner.

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When verifying timing it’s a good idea to roll the crank 90* past your crank alignment mark. Then roll it back CCW to alignment mark. Set tensioner to engine temp (temp gun). Re-verify timing/tension as above after rolling engine over a few times by hand.


Are there rub marks on your timing cover?


People talk about slipping the t-belt over the serp pulley, but I've always just removed the serp pulley. The plastic lower/front shield is easily removed if you don't want to remove the serp pulley.

[RickHaleParker]

When setting the tensioner, go past the set mark and then come back to the set mark.

[- Pete -]

Hang on a second here. Is your idler and belt alignment truly that far kitty-wompus? If so, that idler bearing is kah-poot! That or the 2 bolts securing the idler have loosened themselves.

I'll post an edited photo, but if so, I would not start that engine until you can replace that idler!


The angle of the dangle on this appears off & worrisome to me.

[darrylrobert]

Thanks i will check it tomorrow, hopefully just the angle ofthe photo. the belt is not genuine volvo so thats a good enough reason to change it anyway and redo the tensioner. The ambient temp was 20c but the car was upto running temp when i took the photo.

[abscate]

I’m still googling “ kitty-wompus” before I can add anything.

[oragex]

If the belt is moving left-right on the cam pulleys, it's a problem with the tensioner. I'm not saying it's really bad, but worth replacing it. My belt was also 'walking', after replacing the tensioner is now steady. Also, the belt should be sitting about centered on the cam pulleys, not near the edge. If you hear a loud noise, the side cover may also be rubbing against the cam pulleys (look for fine dark plastic material).

To set the tensioner is a bit tricky, also read the video description and comments.
Careful with the bolt torque: only 15 ft-lbs or (20 Nm)

[vtl]

the belt is not genuine volvo

All my Conti belts did that (swaying left-right on sprockets), I've had 3 or 4 of them.

[darrylrobert]

thanks Oragex thats the video i was looking for.

[SuperHerman]

For future readers: Everything in the system should be in alignment. Crank gear, pulley, tensioner and water pump.

If one has an issue confirm all bolts are correct in size - specifically length, straight and are properly torqued. (I had a V50 in the past where I failed to properly seat the crank gear which caused issues. I don't know how I messed it up, but I did. Fortunately it was solved before damage happened.) At the same time confirm that the tensioner was properly installed and torqued - temperature dependent. Next confirm that the belt and any replacement parts are the correct size. One forum member was provided the "correct belt" which couldn't be installed because it was not the correct belt. Confirm all parts are properly seated. Confirm any reused part is still in working order. Finally, although not common, a improperly installed/torqued/worn harmonic balancer can cause excessive wobble.

Unless one has never changed a part and they are factory original - always consider a wrong part(s) may have been installed even from the dealer. Mistakes happen, parts and their numbers are updated, and monkey mechanic fixes are common. If all these check out - start looking at any wobble or noise from the serpentine belt circuit.

The timing belt should have no visible side to side movement, maybe a very tiny (if any) bounce near the tensioner slack side. The serpentine belt should also have no visible side to side movement, but a little bounce near the tensioner is rather common.