1995 MkI Petrol.
I've just had the cambelt changed at my local garage. The mechanic said that he always liked to change the "rollers" as well but when I went to the main dealers to buy the bits I was told that I only needed the cambelt and tensioning spring. The head mechanic spoke to me and said that they never change the rollers and have never had a problem. Besides which the rollers were an extra £100.
So just the belt and spring were changed and now there is a noise which seems to be coming from the top of the engine (cambelt end). The noise is very pronounced when the engine is cold and is only just audible when it warms up if you know what you're listening for. When cold the noise seems to be present between tickover (which seems to be a lot higher than it was) up to 2000 rpm. As it warms up the noise is only there at 2000 so as you accelerate you quickly pass through the noise. It's difficult to describe the noise but to me could be likened to a thin piece of metal vibrating very quicky.
I haven't had chance to return to the garage to let him listen to it yet and fear that as the engine will be warm when I get there he may have trouble hearing it.
If this was a roller then I would have thought it would be present all the time. Does anyone have any ideas please.

If they are not tensioned properly they will resonate on the non-tension side. It sounds a bit like a vibrating noise more promenant when you take your foot off and the revs are dying.

you could always fit a straight through exhaust so you don't hear anything at all through the delicious rumble. Only the crack of a bolt hurtling out of your tyre at 100mph disturbs the 'purring'.

Or I would just take the car back to the guy and tell em theres a fault. The heatshield on these things sometimes cause a vibration if its not fitted back right. If the problem continues, torch the garage. Then it won't happen to anyone else.

this happened to the wifes rav 4 when i changed its belt , i think the timing is out by a nad , but seems to put itself right after a day or 2 of driving . sounds like cam shaft/tappet wear . if the guy never took the spark plugs out and turned the engine its possible he squeezed oil from a hydraulic tappet .

It's going back in tomorrow. He's had a listen to it and thinks it's the bottom cover which is a bit loose. I hope it's that simple.

Bothwell, if I do need to torch the garage do you have any suggestions for an accelerant. Petrol's soo expensive these days.

Cheap Polish vodka's probably the best bet. Theres other stuff as well I believe but if its mentioned, yer emails get watched by CSI or whatever they're called....

Damn - thats the knighthood oot the windae!

Few years back, on a previous car, I had a whining sound (similar to a supercharger) from the engine after a cam belt change. I think the garage had to reset the belt tension.

It's been fixed. It turned out to be the tension of the belt as suggested by a couple of people here. Thanks to everyone who replied. I won't need to waste that polish vodka after all.