had my belt tensioner changed belt keeps going over when I start car after being re lined anyone help thanks

Not clear with that image you post, but are the belt ribs facing the outside as it passes over the alternator pulley?

Who replaced the belt tensioner?

It looks like either the belt is inside out - or it has been fitted with a twist.

My cuzzion done it he said he compared both tensioner they was same before he fitted god knows what he done 

I will get a better picture give me 5

If you look your car up on 

 

https://navigates.gates.com/emea/

 

select the accessory belt, it normally shows you a fitting diagram. 

Does look like the belt is inside out. It should sit in the grooves on the alternator pulley and the crank pulley. Either that or something is out of alignment and pushing it off. If its not in the grooves the slightest misalignment would cause it to slip off.

Alasdair

32 minutes ago, Alasdair1 said:

Does look like the belt is inside out. It should sit in the grooves on the alternator pulley and the crank pulley. Either that or something is out of alignment and pushing it off. If its not in the grooves the slightest misalignment would cause it to slip off.

Alasdair

The V grooves mainly serve to increase the surface area (therefore grip) of the belt. That belt does appear to be fitted incorrectly, but still waiting on clearer image.  

Hi guys will get a clear image now 

 

That belt is definitely fitted incorrectly - as another poster has said, the ribs must be facing against the pulley surface. 

Reckon its inside out and maybe wrong fitting. What engine do you have in the car

Alasdair

 

Okay thank you and 1.8t 20v 

2 minutes ago, Ashley2714 said:

Okay thank you and 1.8t 20v 

Got this from gates online

 1U5 RS 1.8 T FWD Estate, AUQ engine.

I just looked at belt there 2 ribbed side on belt I do have ac also ?

Am I supposed to have 2 ribbed sides as that's what's on mine atm

Not sure, Havent come accross one with ribs both sides before. From the gates pic the belt should run on the outside of crank,alternator and power steering but the inside of aircon and tensioner which would explain double sided ribs.

Alasdair

Edited 7 February, 20251 yr by Alasdair1

The belt tensioner does not have a drive component, so would not require 'ribs' (act. multiple V) to maximise drive contact.

I am sure my Octavia 3 (with AC) aux. belt is flat-sided on the outside.

Pretty sure my octavia mk2 1.9tdi is one sided as is my 1.6tdi 12 plate. I always use Gates. Maybe the MK1 is different or perhaps you have the wrong belt.

Alasdair

Dont suppose there is a part number or manufacturer on the new belt. If its slightly too long it maay not be tensioning properly.

Edited 7 February, 20251 yr by Alasdair1

@Ashley2714 As others (and my 1.9TDi) that belt looks outside in.

13 minutes ago, Paws4Thot said:

@Ashley2714 As others (and my 1.9TDi) that belt looks outside in.

Its grooved on both sides.  As said havent come across one on skoda but think the beetle 1.9 has double sided from memory on my daughters old one. 

Reckon its the wrong belt but may be wrong.

Just checked febi parts finder and there are two One sided for non aircon but double sided for aircon. (You learn something everyday) Part number for double sided is FEBI 34459 Febi list skoda part numbers 06A 260 849 C ,06A 260 849 B 1195mm long

Alasdair

I know exactly what the problem is.

 

Its easy to run the belt the wrong way around the tensioner and/or idler pulleys, the falling off is a big clue that the tensioner has run out of travel.

 

A better description would be following the wrong path.

 

I did it myself as the incorrect routing looks the most obvious, I didn't have the benefit of a diagram and it took a lot of head scratching, the correct routing looked so so wrong but the belt tensioner sat in the correct mid position and the belt covered a greater circumferential area on the driven pulleys.

3 hours ago, Alasdair1 said:

Just checked febi parts finder and there are two One sided for non aircon but double sided for aircon. (You learn something everyday) Part number for double sided is FEBI 34459 Febi list skoda part numbers 06A 260 849 C ,06A 260 849 B 1195mm long

Alasdair

 

The spare belt I carry is one for non AC, it was a deliberate choice, I bought it when I had an AC coupling problem so I could run with the unit disconnected, as a spare belt it will serve for 2 potential breakdowns, a broken belt (temporary replacement) and a broken AC pump.