Cam belt inspection

[Stewart7]

Dear all

As suggested by the service manager when I bought my Octavia, I've just done a 4 year cam-belt inspection.

I didn't want to disconnect any pipes or cables so couldn't get the inspection cover completely off, and had to use a dentists mirror and torch to see all of the belt.

If anyone is interested, I have some pictures and can pass on some info about what it was like to do.

Would this be of use to anyone?  And is this the right place to post it?

Thank you

Stewart

[Saints92]

The belt doesnt fail, the pulleys the belt runs on do. 

 

How did you check them?

[Guest]

Did you use a dentist mirror because it was a toothed belt?

 

For a number of years now Skoda has recommended checking the cambelt at 5yr so even back in 2015, the service manager was giving out-of-date advice. No harm done checking sooner I guess but have my doubts you've checked it properly.  

[OldBoyScout]

I see that Halfords are offering cam-belt inspection free of charge, subject to asking the customer some questions about time and mileage.

 

I have never had one inspected. Always been told they should be replaced at the recommended interval regardless of condition.

 

[Stewart7]

11 hours ago, Saints92 said:

The belt doesnt fail, the pulleys the belt runs on do. 

 

How did you check them?

I've seen or heard nothing on this forum or anywhere else about the pulleys failing so didn't try to check them in any way.  They were both nice and clean and shiny.

To answer other's questions above, I Used the mirror to look at the belt from the side so I could see the profiles of the teeth, and with the torch, I could see the whole width of the teeth from underneath.

It took about 3/4 of an hour to check the whole belt.  I made a small mark on the belt with tailor's chalk so I was sure I checked it for one whole revolution. 

Turning the crank 1 or 2 clicks at a time until about 4 inches of fresh belt came into view, check with mirror & torch, then crank to get the next section into view.

I could only crank 1 or 2 clicks at a time before my fingers were hitting the end of the generator pulley.

As each piston came up onto compression, because of the angle of the ratchet handle, I could only manage 1 click at a time.

 

Stewart

[Stewart7]

10 hours ago, Scot5 said:

Did you use a dentist mirror because it was a toothed belt?

 

For a number of years now Skoda has recommended checking the cambelt at 5yr so even back in 2015, the service manager was giving out-of-date advice. No harm done checking sooner I guess but have my doubts you've checked it properly.  

Nice one Scot.  Dentist's mirror, toothed belt.  I also like a good corny joke.

[Saints92]

6 minutes ago, Stewart7 said:

I've seen or heard nothing on this forum or anywhere else about the pulleys failing so didn't try to check them in any way.  They were both nice and clean and shiny.

 

I've been in the motor trade over a decade now, and never seen a belt break. The pulleys are the weak spot.

 

I'm very over cautious but I'd be loathe to go beyond specified time frames based on just the belts condition.

[Stewart7]

3 minutes ago, Saints92 said:

 

I've been in the motor trade over a decade now, and never seen a belt break. The pulleys are the weak spot.

 

I'm very over cautious but I'd be loathe to go beyond specified time frames based on just the belts condition.

I'm also very over cautious and try not to leave anything to chance, so I'd be very interested to know how the pulleys fail, and if you get any warning.  Do they break up?  Do the bearings go?  Do the bearings get any lubrication from the cam shafts?

 

[OldBoyScout]

10 hours ago, Scot5 said:

For a number of years now Skoda has recommended checking the cambelt at 5yr

I have had my older Octavia for 12 years now and my local Skoda dealership has always recommended replacement rather than just checking at 5 years. Nice earner for them as they recommend changing the water pump at the same time.

 

My 2015 Scout has just been in for service and MOT, but not cam-belt. I expect they will catch me with that next time.

 

[Saints92]

11 hours ago, Stewart7 said:

I'm also very over cautious and try not to leave anything to chance, so I'd be very interested to know how the pulleys fail, and if you get any warning.  Do they break up?  Do the bearings go?  Do the bearings get any lubrication from the cam shafts?

 

 

Water pump the most usual cause on cars with that set up. It wears and, if you get your hand on it, you can shake it about side to side and up down, which obviously begins to throw the belt off when the engines running. Cant check that without removing the belt, you sometimes get a visible leak/noise before it goes completely, sometimes not.

 

The idler pulleys dont get lubricated and are just bearings, as with every bearing, eventually they wear out and again you'll get free play on them, with them not being toothed pulleys the belt finds it easier to come off once they start to move. Some models have plastic idlers which over time become brittle and start to crack.

 

Rarer cause is the spring loaded tensioner blackening off as it ages and weakens, but I've only seen that once.

 

I dont know what your model is, but I'm always afraid of when people only check the belt and assume its fine. I'd feel terrible if I seen someone saying it, said nothing myself, and then they came on here talking about it failing. As I say though, I'm very over cautious, and there'll be people on here who swear theyve gone decades without changing the belt and being fine, so it's all up to yourself. Just trying to help advise you.

Edited 23 August, 2019 by Saints92

[Neolithian]

12 hours ago, Saints92 said:

 

I've been in the motor trade over a decade now, and never seen a belt break. The pulleys are the weak spot.

 

I'm very over cautious but I'd be loathe to go beyond specified time frames based on just the belts condition.

I have a few taxis, high mileage vehicles I’ll grant you. Nonetheless the weak points tend to be water pumps and the teeth can come off the belt to cause loss of timing - however I’ve been lucky so far  as the engine has gone noisy and just taken it to the garage and not done damage (twice).