Timing belt tensioner...1.4 TDI PD

[bob54321]

Hi,

I've recently done the timing belt and tensioners (and water pump) on my 1.4 TDI PD. I did it using the official skoda service manual (which you can find out there on the internet, it's really good - probably better than haynes manual, there's on here for my engine:

http://sziget.mine.nu/~tAB/nem_megnezni/Skoda/Biblia/Fabia/Engine AMF.pdf

Plus, I consulted several forums/youtube videos, this one is good, although not exactly like the 1.4 TDI PD I have:

The operation went more or less fine, had a bit of wrestle, did a fair bit of beard-scratching, but finished it and car runs fine. Except for a slight whining noise which follows the engine speed RPM's. I think, although not certain, that this noise was there before (only had car a week or so).

Years ago I did the timing belt on a Polo, and I remember that I adjusted the tension way too tight and it sounded like a hover-craft, slackening the tension cured the noise. The Skoda sounds like it could be a similar thing....which is why I am questioning the tightness. When I tensioned the belt, I did it as described in the service manual and illustrated in this video:

http://www.youtube.com/watch?v=RSQA0kF7Sh8

You can see the silver pointer on the back rotate clock-wise as tension is applied, the correct tension is achieved when the pointed is in the middle of the two noggins. I did have a bit of confusion to begin with, as the instructions that came with the new tensioner were different to that in the service manual. The tensioner came out the box with a pin in it and the instructions said to put the tensioner on, then put belt on, then apply tension and pull out the pin (or similar). Unfortunately I could not get the belt on with the pin in (i.e. there was not enough slack in the tensioner), so I removed the pin then follow the service manual instructions. Note: with the pin removed, the new and old tensioner seemed to operate identically - so I am a little baffled as to what the reason for the little pin is? Anybody?

Now when I tensioned the belt I though it seemed a little tight...but I assumed this is normal as I've followed all instructions to the letter. I even compared old belt with new to check it was exact same size. So is it normal to have it pretty tight? And does you're 1.4 TDI PD have a slight engine whine?

Thanks,

Matt

[bob54321]

Anybody?

Does this sound normal to you:

http://217.168.155.130/engine-noise.m4a

Cheers.

Matt

Edited 18 January, 2011 by mattiker

[rotodiesel]

There seems to be a lot of misinformation about VAG timing belt tensioners.

The early PDs had a hydraulic tensioner - shown in your first link which requires the use of the spacer plate on assembly.

All later PDs and (I assume) all of the 3 cyl engines use a Litens friction damper with the installation pin. The purpose of this pin is to allow you to set the tensioner in the fully retracted position to aid belt fitting. To do this, fit the pin and with the tensioner in its normal position on the cylinder head (tang in slot) and the securing bolt loose, wind the tensioner clockwise until the pointer is just to the right of the slotted scale plate. Lock in this position. This fully retracts the tensioner allowing the belt to be easily fitted.

The locking nut is then slackened, the tensioner revolved anticlockwise and the pin removed. The tensioner is then rotated clockwise until the pointer is centrally in the slot.

My view is that the VAG torque figure for the tensioner securing nut (20 Nm + 45 deg) is excessive and can pull the stud out of the Al head. Use your own judgement - I set mine to 20 Nm + 20 deg - which is plenty tight enough.

As usual, the VAG instructions for this Litens tensioner and its lock pin are useless. No wonder the dealers mess up timing belt changes.

rotodiesel.

[mogwye]

A whining noise usually means a too tight belt.

DB.

[bob54321]

All later PDs and (I assume) all of the 3 cyl engines use a Litens friction damper with the installation pin. The purpose of this pin is to allow you to set the tensioner in the fully retracted position to aid belt fitting. To do this, fit the pin and with the tensioner in its normal position on the cylinder head (tang in slot) and the securing bolt loose, wind the tensioner clockwise until the pointer is just to the right of the slotted scale plate. Lock in this position. This fully retracts the tensioner allowing the belt to be easily fitted.

The locking nut is then slackened, the tensioner revolved anticlockwise and the pin removed. The tensioner is then rotated clockwise until the pointer is centrally in the slot.

rotodiesel - so are you saying the pin is only there to facilitate easier fitting of the belt? I managed to get the belt on without the pin in, it was a slight squeeze but easy enough. I then tensioned it like you described, so that the pointer was positioned in the gap in the back plate. So, I think that means I've got the correct tension?

Anybody listened to the sound clip? Like I said previously I not 100% sure this sound wasn't there before, or in fact if it's pretty normal for this engine!

I'm going to scan in the instructions that came with the tensioner and post here later, just so others who follow get a heads-up - they are pretty shoddy!

Cheers,

Matt

[vladisslav]

Hello, 

 

I have the same problem of "whining" sound in my amf engine, after timing belt, pulley and tensioner replacement. 

I firstly thought that the belt is too tight and went back to the mechanic. He said that according to him is OK and the tensioner automatically  regulates the tension, and he cannot influance on the tension. Is this true ?