Help me fix my Car. 1.8T (aux belt)

( |-| |2 ][ $ · 26 Nov 2010 at 07:17

I own a Seat Leon FR, so it's the 1.8T 20v engine.
Last winter I noticed the aux belt squeeking during the cold spells, I got a quote at the time for £280 to do the belt and tentioner, knowing better I left it and it was fine all summer.

Come a few weeks ago it's started doing a few little churrps for a few mins after starting, so I thought I'd attempt the job myself.

I started just with the tensioner as I thought this might have slackened over time, unfortunately the noise was just the same. Anyway bringing the costs of parts to £60 I bought a new belt and fitted it yesterday.

Went on fine, started the car fine, turned it off and went back inside.

Cue two hours later starting the car and the belt comes off. I put it back on, drove 20 miles home and parked up for the night. 06:30 this morning I set off for work, clunk, off it comes again.

Now my very angery. I'm 100% it's fitted around the pulleys in the right order, and 90% sure it's in the right place on all the pulleys (ie the middle) so why does it keep coming off when starting the first time, but not the second?

Help?!

Maz · 26 Nov 2010 at 08:15

It's not tight enough if it keeps coming off.

( |-| |2 ][ $ · 26 Nov 2010 at 08:24

Maz said:
It's not tight enough if it keeps coming off.

I compared the size against the old belt and it's exactly the same.

I'm at a loss as what to do now though, I've got a brand new belt and tensioner which don't work, how could it not be tight enough, there's nothing to tighten.

Matt82 · 26 Nov 2010 at 08:39

when you say you changed the tensioner, did you change the pulley too?

id guess on a duff tensioner keeping it tight enough

when the engine is running, are all the pulleys running true?

( |-| |2 ][ $ · 26 Nov 2010 at 08:53

Matt82 said:
when you say you changed the tensioner, did you change the pulley too?

id guess on a duff tensioner keeping it tight enough

when the engine is running, are all the pulleys running true?

That's depends what you mean by the pulley, the tensioner has a pulley wheel on the end of it.

But that new tensioner ran fine for a week on the old belt, (all be it with a few squeeks)

I'll try starting the car again at lunch time and if it comes off I'll try the old belt.

Firestar_3x · 26 Nov 2010 at 08:58

Provided the belt is the correct one for your car, you've either miss aligned something (tensioner not flush up against the block) or you've not fitted the belt round the pullys in the correct order / you have the slack in the wrong place in the belt.

collisster · 26 Nov 2010 at 12:25

The tensioners are self tensioning i think via a spring, take it off and give it a waggle around and make sure nothing is holding it back or slowing it down.

Dogbreath · 26 Nov 2010 at 12:42

( |-| |2 ][ $;17870560 said:
Now my very angery. I'm 100% it's fitted around the pulleys in the right order, and 90% sure it's in the right place on all the pulleys (ie the middle) so why does it keep coming off when starting the first time, but not the second?

When you say "keep coming off", has it done it more than once? Starting on a cold morning the PS pump and alternator will be putting a lot more load on the belt than a warm engine.

With the engine running, can you see that the belt is running in the middle of the tensioner pulley? If you rev the engine does the belt flap/move around significantly?

ci_newman · 26 Nov 2010 at 14:53

Dogbreath said:
When you say "keep coming off", has it done it more than once? Starting on a cold morning the PS pump and alternator will be putting a lot more load on the belt than a warm engine.

With the engine running, can you see that the belt is running in the middle of the tensioner pulley? If you rev the engine does the belt flap/move around significantly?

"I stuck my head under the bonnet and the aux cable came off and slapped me in the face"

( |-| |2 ][ $ · 26 Nov 2010 at 14:59

I've just had another look at this.

Started first time okay but then the second time it came off.

I've turned the belt inside out, not sure why, it appears to be the same bough sides and it's not labeled up at all. And it's started okay four times in a row.

Things I have noticed, no the belt is not running on the middle of the tensioner pulley. The pulley is very close to the engine block and the belt runs only on 50% of the pulley.
The belt definately is on all the pulleys correctly.

As far as I can tell though this is how it was before, well maybe it was more like 70%.
I guess I could add a washer in to move it away from the block a little but there wasn't a washer on before.

Couple a of people with 1.8T engines perhaps take a photo of theirs? I'd be interested to see how it compares to mine?

Firestar_3x · 26 Nov 2010 at 15:01

My Aux belt covers all the pully and doesn't fall off to one side, sounds like you could have the wrong tensioner.

( |-| |2 ][ $ · 26 Nov 2010 at 15:08

Firestar_3x said:
My Aux belt covers all the pully and doesn't fall off to one side, sounds like you could have the wrong tensioner.

Well I will admit to buying a none OE one off VW spares but I compared it to the one I took off and it was EXACTLY the same (aside from the VW logo)
I also ran that with the old belt fine for a week.

http://www.vwspares.co.uk/product_info.php?products_id=118

However I think it's clear something is wrong, I am going to look for some washers I could add on to move it a couple of mm away from the block.

Firestar_3x · 26 Nov 2010 at 15:09

Might have missed it before but does the new belt have the same number of ribs and does it have the same groove profile?

( |-| |2 ][ $ · 26 Nov 2010 at 15:11

Firestar_3x said:
Might have missed it before but does the new belt have the same number of ribs and does it have the same groove profile?

Yes

Firestar_3x · 26 Nov 2010 at 15:14

The only other thing i can think of (but this won't fit your belt not running on all the tensioner problems) is when you fit the aux belt i had to leave the belt slack on a particular side of the tensioner, otherwise the tensioner can't pull the belt tight.

I think the slack has to be on the side that the tensioner roller pushes against, have it anyplace else and the belt is likely to skip off.

( |-| |2 ][ $ · 26 Nov 2010 at 15:30

Well that does make a little sense but the system is free to move and mine only seems to have the problem when being started after it's been running. (and has cooled down again)

I'm going to consider swaping back to the OE tensioner or perhaps adding some washers in. (thinking about it, I'm concerned the side of the tensioner wheel might even be touching the block)

I'm angry now because I'm at work and I have got to work all weekend and don't have the sockets to take the tensioner off.

Might see if my parents can drive them up to me tomorrow.

( |-| |2 ][ $ · 28 Nov 2010 at 12:31

So yesterday I put the old tensioner back on with the new belt and it works great.

Matt82 · 28 Nov 2010 at 14:34

and the squeak? i haz a squeak. im betting either on tensioner pulley or one of the ancillaries itself

( |-| |2 ][ $ · 28 Nov 2010 at 19:05

Good so far, fingers crossed.

Given my experience I'd start with a new belt, it's only £20 inc del. and is a 5min job, 2 mins when you've done it a few times.

After that perhaps try the tensioner which is a fiddly but still only a 15min job. As above my experience with a none OE tensioner was not good.

Although i think I still might try it again to see if it was my fiting mistake or it really doesn't fit properly.

If it still squeaks after that then you might need a microphone type thing to determine the source.