Cam Belt tensioner - where do I stand?

Give it a petrol leak and when it goes up have an insurance claim.

Changing the belt if removed is normal practise. The problem for the garage is that with worthless cars like that, the owners kick up a fuss if the bill is too high, so the garage will try to keep the price low so as to avoid confrontation. The tensioner would add another 40 quid or so on the bill and since usually the people that buy cheapo cars are usually very mean or very poor or very clueless, the garage took the quiet life option and didn't change the tensioner. I doubt you have any chance of claiming off the garage.

Mrcheerful

You do not say whether they did replace the tensioner, whether the cambelt and therefore tensioner was near to its service interval or whether you have asked them about it so the following may or may not be of help

I had the tensioner go on my Volvo a couple of thousand miles after a belt/tensioner change at the recommended service interval Fortunately this happened at tickover so just put the engine management light on

Garage (independent not Volvo dealer) replaced tensioner and fitted a new belt as well when I asked who pays they said Volvo as the part was faulty

I asked what would have happened if this had occurred at speed and screwed the engine Reply was we put it right and charge Volvo

If your garage had replaced the tensioner and it had gone faulty then there should be no cost to them or you Repair may still be uneconomic but you may get some compensation

Tony