PD 130 cam belt tension??

[Wobby]

I have today changed the cam belt and water pump on my Passat TDI (242k).

Firstly.. A big thanks to Rusty.... It was the water pump that had lost its impeller, i found it hard to believe this could be the problem. Amazed the engine could have the cooling it had for the 600 miles i have done in the last few weeks with virtually no water pump!

Bought the Sealey PD engine tool kit and everything went ok except a few studs were seized and either rounded or snapped so it took a little longer to drill and tap about 6 of the fixings.

The existing belt had covered 120k so was well past its best! It looked in an ok condition but was very very loose, i am amazed it hasn't jumped. I can only assume the hydraulic tensioner has helped prevent it jumping as on any other engine i have worked on i am sure it would have.

My questions...

1. How does the hydrualic tensioner work? Does it run an additional fixed tension once the engine is running or does the belt tension have a steady increase as revs increase?

2. How tight should these belts be once fitted, do they feel very tight? Mine feels nice and tight with only slight play, the old one i had more than 1" side to side movement in between the cam and pump pulleys. It was tensioned with the correct tools and with the instructions, does it sound right?

Been for a run and the over heating problem is gone and the temp sticks bang on 90. Also the engine sounds much healthier, with less vibration and quieter! Suprised the difference this has made

Thanks for the help

[pingpongpo]

Thats probably why VW say you should change it more often

[Wobby]

Your probably right.

I have been in 2 minds for a while now regarding changing the car, so it hasn't had the looking after it deserves! It does need a few bit sorting out but i have decided to keep it going and take on the challenge of 300-400k!

It will need a new front bumper and inserts (something fell off a lorry and knocked a large hole in it). Power steering cooler also suffered some damage but is still working.

I have a feeling the clutch will have gone before 300k.

shocks and springs may need attention, i think something is not 100%

If i have to do/change major engine components the challenge has been lost and the Passat is considered a poorly made heap of s**t

[Tobes49]

1, The hydraulic damper is a pressurised unit with a very stiff damping on the rod, The cam belt stays at the same tension through the rev range but alters with engine heat. The tensioner is fitted onto the slack side on the belt.

2, On PD engine the cam belts are like bow strings when fitted and seem very tight.

To set the tension you should make sure there a 4mm gap between the tensioner plate (the part the damper rod hits on the tensioner) and damper body (not the damper rod). When the engine is cold and the crank has been turned 720deg's.

[Wobby]

Thanks Tobes.

We set it said to in the Sealey toolkit and manual says so hopefully its ok. Will look at your method on next change.

Cam timing must have been moving all over the place, a nice steady run today and i have seen 60.8 MPG. Been lucky to get to 53 MPG on runs lately. Car used to run over 60 until i had belt done at 120k.

Always thought the reduction in MPG and extra noise was engine wear. New belt has taken the engine back 2 years in terms of noise and MPG, guessing the extra MPG would have paid for the belt over that time. I live and learn!