Timing belt, tensioners and water pump on the Audi TT 8N...easy does it (not)

The timing belt on the TT was approaching its end of life; although there was still a bit to go before the 180k interval, the belt was already 8 years old, and needed replacement because of that.

A timing belt job on the 1.8t is not overly difficult, except for two major design issues:

• The timing belt runs around the right engine mount. So to replace the belt, the engine mount must come off.

• Space is a little tight, particularly around the said engine mount, so you have to wiggle the engine up and down to be able to access the bolts.

Otherwise there should be no major hurdles, unless your bolts are stuck and break. Oh well.

Both the Bentley and Haynes manuals describe the procedure in good detail. Basically the steps are:

Removing the coolant overflow, power steering bottle and the charcoal canister (left right corner below), pushing them to the side. There's no need to remove these, just removing them from the brackets gives ample room, see picture below. Note that in the picture the valve cover and intake manifold are also off, for other purposes (another post coming on the oil leak issues).

Removing the serpentine belt, below. The serpentine belt tensioner can be released by turning it with a wrench.

Pulling the timing chain covers.

Supporting the engine and removing the right engine mount by lifting and lowering the engine. The engine mount is in the top left corner of the pictures below, circled in pink. As can be seen in the images, the mount resides inside the timing belt.

You can get better access to the harmonic balancer by disconnecting the intercooler piping, below.

First big hurdle here. I took a small drill bit allen key to remove the bolts on the balancer. I thought these would be fairly easy to remove since they are not terribly big. Bad idea. One of them was really stuck though and the allen bit twisted in the bolt, mangling it completely. And as the bolt is recessed inside the balancer, it is really fun to get to. After a lot of effort, it did come out with a bolt removal socket, even though it is a round allen bolt and not a normal hex bolt.

The harmonic balancer can be locked in position for removal. It's going to be tight though.

To remove the timing belt, the tensioner must be loosened. There is a VAG tool for this but you can make your own as well from a 5mm bolt and washers. Tightening the tool is a real pain though, as it is in a super tight space, accessible from below in an awkward position.

Upon installation, I made the second big mistake and tightened the engine mount bracket incorrectly when putting it back. I had a hard time understanding the references in the Haynes manual and overtightened one bolt, which snapped almost immediately... The engine mount bolts are stretch bolts and you should be careful with them. Fortunately the bolt was in a spot where it protruded a flange in the engine block and was accessible from behind. It was quite the forearm workout to remove the broken bolt from the backside.

The engine is quite oily in these images. This is before a major oil leak fix operation, which is in another post.

A new timing chain with a new water pump, tensioner and pulley cost 120 euros and a new serpentine belt and tensioner some 60 euros (Autodoc). New bolts for the engine mount (which are stretch bolts and one time use) were about 30 euros (Vagbolts).