Hi, fairly new to the group and first post.
A warm welcome to the forum.

I have a mk5 GTI and when cold i can hear a kind of squeeking noise which i have identified as coming from the top of cam belt area, if i put my ear to the top of the cam belt cover i can hear it. If i drive down the road i can hear it echoing off walls and other cars but by the time i drive 1/2 a mile its gone, i assume it is something heating up and possibly expending?
How old is your car? How many miles has it done? And what is your three letter engine code (just the first three letters, sommat like AXX or BWA - I don't need the full six digit number)?
From what you describe, it sounds as though it could be either of
two three things (or both!). One of the problems could be the actual timing belt is either damaged or contaminated with oil. The other issue could be one of the idler rollers, or even the tensioning roller - might have worn bearings. Finally, your water pump could be starting to go t!ts up. Either way, whichever one (or more) of those problems it may be, they are all inter-related. So I would recommend getting the cam belt and its associated components checked out as a matter of urgency. If the belt, rollers, water pump are all OK, then fine - but if any of them let go, you could be in for considerably expensive engine rebuild bills.
I took it to the dealers and they said a crank seal was leaking a bit of oil and that was getting onto the alternator belt, this seemed a likely cause as it could burn off the oil as i drive down the road. I had the seal and new belt put on but i can still hear the noise.
If the crank seal was leaking and contaminated the alternator belt, then it is extremely likely that the timing belt was also contaminated. Did the stealer not check this? Is your car still under warranty?
Has anyone else heard of anything like this?
Personnaly, no, not on the GTI. However, on engines of similar design, it is not uncommon. In fact, oil contamination is the leading cause of timing belt failure.
I now GTI's can be noisy but this is definitely something different. Any help much appreciated.
The two most common GTI noises are the rather loud fuel injectors (sound sort of "tappety" or some peeps report them sounding "diesely"), and the drive for the FSI high pressure fuel pump, located near the battery end of the cam cover, can also wear.
HTH, any more Qs, then post away and we will do our best to help.
