Timing belt - missing tensioner?

[abscate]

The picture of the mechanical tensioner above shows an incorrect tensioning.

The 6 mm hex cam should be on the bottom side of the tensioner , not the top

Many people get this wrong.

I’ll document this better.


The mechanical tensioner is superior as it allows greater temperature compensation. The timing belt service interval was lengthened by 50% with this change.

[abscate]

Here is the procedure for setting the mechanical tensioner

Note that you tension this turning COUNTERCLOCKWISE until the indicator arm comes past the setpoint, then ease back to the correct setting based on engine temperature.

A 6 mm hex key is best for the tensioner, starting at 10o/c position, the hex will end up on the bottom of the tensioner near 6 o’clock, when done.

A12 mm wrench tightens the m8 hex bolt once the set point is right


Tighten the timing belt as follows:
Turn crankshaft clockwise carefully until the camshaft belt is tensioned.
The belt must be tensioned between intake camshaft pulley, idler pulley and crankshaft.
Hold the belt tensioner center screw secure and turn the belt tensioner excenter counter clockwise until the tensioner needle passes the marked position.
Then turn the eccentric back so that the needle reaches the marked position corresponding to the relevant temperature.
At 20°C (68°F) the needle must be centered in the window.
See figure above.
Secure the eccentric and tighten the center screw to 20 Nm (15 lb ft)

[Richard99]

The picture of the mechanical tensioner above shows an incorrect tensioning.

The 6 mm hex cam should be on the bottom side of the tensioner , not the top

Many people get this wrong.

I’ll document this better.


The mechanical tensioner is superior as it allows greater temperature compensation. The timing belt service interval was lengthened by 50% with this change.

Exactly. I bet most mechanical tensioner haters probably did not install, or did not have it installed correctly.

[erikv11]

If water pump is original and not leaking...leave it alone.

I've been occassionally hearing a "groan" noise from the passenger side when the car is in motion but not yet warmed up. I was concerned the water pump might be failing...

Water pump is Aisin btw. Timing belt is OEM.

The oil cooler thermostat is well known to groan like that, especially when the engine is cold.

[scot850]

As it is a turbo 98 year, chances are the groan, is when it is cold. The source is probably the oil cooler thermostat. The make weird noises when they get old ( a bit like me apparently!).

Neil.

[smacknab]

Haynes manual has a pretty clean explanation for installing and adjusting the mechanical tensioner, I can upload the pics of it if you would like

[KHolden]

By way of a follow up - I'm pretty sure Volvo expects you to take that crank pully off. Getting the old belt off and a new belt on brought on a new level of obscene vocabulary from me. Did they really have to have bolts that come within an 1/8" of the crank pully making it near impossible to maneuver the timing belt off?

I'm just glad I never have to do that again...

[KHolden]

Haynes manual has a pretty clean explanation for installing and adjusting the mechanical tensioner, I can upload the pics of it if you would like

Thanks, I got it. It was actually pretty easy except that the tension on the belt changes depending on where the engine cycle currently is. When I went to turn it over manually a couple times to verify timing, I noticed the spring indicator moved significantly back and forth. I suppose that's actually the point though - it maintains a constant amount of tension at all times.

[scot850]

I had a nightmare with the mechanical tensioner when I first did this job. Could not get the tensioner to work correctly. It was an aftermarket version that was faulty. Swapped it for a Volvo OE and what had taken 3 hours of swearing and failure took about 5 minutes to set up correctly.

Neil.