whats 'tensioner'?

[Overseer]

can some expain what this is pls...

my cars going in (2 months early) for its full service soon, and i'm getting the cam belt done at the same time (the schedule i got with the car said it should be changed this time) at my local dealership they recommended i get the tensioner replaced too.. i'm like.. uhh great.. whats that?

if it goes is it dangerous?

is it worth doing?

[MK316V]

As far as I know it keeps the cambelt at the correct tension, thus the cambelt not becoming lose and damaging your engine. So yeah its quite important.

On a side note I had my cambelt snap at 80mph on the M6 and cost me ?900 to get the engine running again  :'( my engine had only done 54,000 and the cambelt was due for replacement at 60,000 miles.

So I would get the tensioner and the cambelt changed at the sametime so you know where you stand.

[richandhazel]

Its a good policy to replace the tensioner at the same time. They aren't expensive and have been known to fail.

[golfvr6]

The tensioner simply does what it says, it keeps the cambelt tight. What usually happens is after high mileage, the bearing in the tensioner wears out and seizes up, this strips all the teeth on the cam belt, and bang goes the engine. So it is good policy to change it.

[Overseer]

will do

[The VolksWizard]

if the tensioner fails it's as bad as the belt breaking.

compared to the cost a belt, a tensioner is quite a bit more, especially from a VW dealer, ?40 vs ?10 or thereabouts so can add to the bill a fair bit.

Here's a tip - as soon as you have a cambelt change, get the engine warmed up and check it can rev all the way to the red line.

I've experienced too many cases where the timing is slightly out afterwards and it's like the rev limiter has dropped 1000 rpm, not fun when you are on wrong side of road overtaking!

[Overseer]

they said about 40 quid extra.. i'll just tell em to do both at the same time..

[i-espedair]

I used to have a ford (company car). Cam belt was changed at 60,000 as recommended. Two months later i'm heading back from a club in Brighton at 5am and the engine goes bang, pistons hitting valves, limping me home at 1500rpm max!!!

Turns out some trainee mechanic spun the belt tensioner when they changed the belt and decided it would be ok for another 60k. The tensioner should ALWAYS be CHANGED at the same time as the belt!

As a result i always do belt changes my self and always at 50k! VW say 60k for the mk3 golf, some garages say 70K. I know people who have had them break in the 50k's. Never heard of one snapping before 50k. A 50k belt change is nice and safe!

The tensioner on the ford was a small nylon plastic wheel with a brass spring that had done 60k, It is incredable. On the golf the tensioner is twice the size, weighs about 2lb's, is made of solid steel with big sealed bearings in the middle and Made in Germany stamped on it! It is a beast so cost is justified. Looks like one of those guides they have on tank tracks. I use my old one as a paper weight on my desk at work!!!

Good old german engineering! This is why we love our Dubs!

[golfvr6]

I wouldn't always change the tensioner when doing the belt, but i would probably change a belt every 40k. If the car has done over 60k then change the tensioner as well.

[Overseer]

ok guys.. well thanks for convincing me its really a good idea to change both.

I wasnt going to put it through until december (the schedule i got with the car says to do it on 85k or dec '03.. its on 75k right now)... but almost like an omen the vw/audi specialist the car is going to tomorrow (mainly for cat1 cert and some ice related bits..) said "whats the mileage on that.. has the belt been done" outta the blue.. kinda put the willies up me.. so I booked it into the dealership next door to work (how great is that) the next morning