16v timing belt tension?

[cubed 0]

im just about to set about my cambelt on my 90 16v, ive done the job on 8v,s before but hear timing belt tension is more critical on the valver.

would anyone have any advice on checking tension or is it a case of getting the vw tool? any help always appreciated!!

[Supercharged 2]

I think it's the same tool as the 8v's - if so then GSF sell these for bout a fiver...

[davidwort 0]

im just about to set about my cambelt on my 90 16v, ive done the job on 8v,s before but hear timing belt tension is more critical on the valver.

would anyone have any advice on checking tension or is it a case of getting the vw tool? any help always appreciated!!

 

there are two tools, one with two lugs to hold the tensionner still while you torque down the nut (don't really need it) and one that checks the belt tension. VAG garages sometimes insist on using the tensionning device but it's not needed.

If you over-tighten the belt it will squeal horribly.

It actually feels quite slack when correctly tensioned and sometimes you think it's OK and one run of the engine and it then feels too tight.

I've found the best approach is to tighten until you can turn the belt to roughly 90 degrees mid way between the cam pulley and intermediate shaft pulley, run the engine and stop again, then slacken very slightly until it runs without squealing when you increase the revs.

The only reason it's more important to get right on the 16v over the 8v is the 16v will bend valves if the belt jumps more than a tooth or two.

 

David.

[cubed 0]

thankyou very much gonna crack on with that now.

thanks again!!!

[cubed 0]

right job done but the tensioner is causing me problems,if i tighten it it squeals nastily,but if i back it of even the smallest amount the belt flaps,

just wondering if im doin somethin wrong??

[steveo29 0]

back it off till its not noisey

[Gman 0]

I have just done this job too and am having the same problems. I cant seem to get the belt to stop flapping around. I can turn the belt through 90 degrees.

 

It sounds fine when i the engine is idling but as soon as the revs rise a little the belt starts to flap about and make a horible slaping noise. I dont have either of the VAG tools.

 

any help and advise would be great thanks.

 

G

[keithmac 0]

I use the 90 degree rule, the belt does flap slightly but any tighter and you`ve loading up the tensioner bearing which isn`t good! From my experience the proper tension does seem to be too slack, it isn`t. I bought a brand new VAG tensioer and got the same results.

[Supercharged 2]

Guy's - as the tensioner is excentric does it matter which way you rotate it to tension???

[Valerian 0]

Check your tensioner for side to side play in the bearing....their shouldn't be any play at all.

 

Always worth replacing the tensioner anyway .....tad expensive at £35 mark from VAG.......but well worth doing as this part is nearly always neglected on any car.

[Supercharged 2]

Always worth replacing the tensioner anyway

 

VW state you must change it!!!

[keithmac 0]

I always rotate clockwise to tension, if you do it the other way round the belt will try to push the lock nut undone which isn`t good.

[RapidVII 0]

I must have done 2 dozen cam belt changes on the 16v engines, and this has happened to me once or twice,

 

Remove the tensioner and and check it for excess play, it shouldn't have any.

 

Spin the tensioner, if you hear any bearing noise, its on its way.

 

Any excess play, bin it.

 

Any bearing noise, either oil it back up or replace it.

 

For the price of them, id change it TBH.

 

The tensioning ( without automatic belt tensioner )

 

Make sure when you check and adjust the tension that you are at TDC when you do so ( or just a smidge over clockwise is fine )

 

Find the middle of the belt, at its longest point, and tension so you can twist the belt on its own axis no more than 90 degree's. ( If your using a belt tensioner, it should measure 13 to 14 units. )

 

When you've done that, spin the crank 2 turns clockwise ( 720 degrees on the crank pulley ) make sure that timing marks are aligned exactly - cam sprocket and inspection cover on the flywheel. Then check and re-adjust tension if needed.

 

Tightning torques as I remember are tensioner bolt M8-25Nm M10-45Nm

Crank pulley bolts are 20Nm ( on both models )

 

If your car has the automatic tensioner,

 

Note: The engine MUST be cold.

 

Get TDC, turn tensioner anti-clockwise until it stops.

 

Tighten tensioner nut to 25Nm

 

Turn crank 720 degrees until timing marks align ( cam sprocket & inspection hole mark on the flywheel )

 

The marks on the tensioner must align ( if not, retry until they do )

 

Push your thumb in the centre of the belts longest point ( between cam sprocket and the aux pulley ) The tensioner marks MUST move apart. Take your thumb of the belt and spin the crank 720 degs clockwise until the timing marks align. Tensioner marks should re-align.

 

If they do, job done and if it whines, then the problem lies elsewhere.

 

I will assume that your engine has the manual tensioner, most of them usually do, are you hearing the whining noise with the fan belt and power steering belt on and tensioned up ?

 

If you are, take the aux belts off and start the car again, if it still persists and your belt tension is fine, I would say that the tensioner is knackerd.

 

If it whines with the aux belts on, obviously check and adjust the tension, but also make sure the Hex bolts are tight on the pulleys.

 

Follow this and I think you'll be fine.

 

Personally, I used to like to hear them whine ( just a slight whine I might add, not screeming its balls off ) then you know that the jobs done right and its not slack as a bag of nackers.

 

You'll be fine im sure.

 

R7