AHU timing belt tensioner new or old

[boxer246]

Just bought a '98 Jetta TDI, bought with broken timing belt. Pulled the head, so far it looks pretty good, actually, considering the carnage that a broken timing belt often creates. All lifters trash, most valves bent, but head looks really good.

Anyway, the car has 170,000 on it, hard to say if the head's ever been off, but I noticed it has the old style belt tensioner....the all metal one used on pre-TDI motors. Along with that, it has the associated larger stud that goes into the head rather than the smaller diameter stud used on other TDI heads that I own or have seen.

The threads in the head appear cut very nicely, factory like, it doesn't have the appearance that someone drilled a larger hole and tapped threads for the old style tensioner stud, but obviously its a possibility.

My question is, is there any particular reason why the old style tensioner should not be used with the TDI head? I personally have always wondered why VW decided to use a mostly plastic tensioner on the TDIs....they seem really cheap and flimsy. I understand that the earlier TDIs had some sort of temperature related tensioner system attached to the belt tensioner....and obviously this couldn't be used with the old style tensioner....other than that, why is the new plastic one better?

[BigVWman]

My 1z has the same tensioner on the timing belt! It wasn't originally an auto engine though. It started life as an industrial engine!

[boxer246]

Ah.  Good im not the only one.
I'm fairly sure this motor did not start out life as an industrial motor, but I did not buy the car new, so I cant say for sure.  I would highly doubt that it is anything but the original motor of the vehicle.

So you haven't had any trouble with yours? 

You know when I took the plastic timing belt cover off from down by the crank pulley, out fell a little plastic (what appeared to be a spark plug wire separator) clip.  I'm wondering if somehow this fell down into the timing belt and caused the belt to break. 
The previous owner stated that he wasn't sure why the belt broke because "the timing belt was changed at the correct interval".....so naturally when I took the head off and saw this old style tensioner I was immediately suspicious that the tensioner might be the cause....because i've never seen another one on a TDI.  However, the tensioner appears fairly new, good quality (says Germany on it) and shows no signs of wear.

[lucasone]

I would change the tentioner to the newer style because it's spring loaded (auto tentioner) once its adjusted. It's a better design and it will compensate for any movement of the pump if you had to adjust pump timing. Even though the stud is smaller on the new style tentioner it will screw into the head because the threaded end is bigger.

Just my opinion.