Alfa Romeo SZ Technical Page

Timing belt replacement (22/05/10)

The timing belt on an Alfa Romeo V6 (12v) should be changed every 60,000 kilometres (Schedule). For my car, that means more frequently as it has yet to break 8,000 miles!

Here is the process I followed, please read the SZ Workshop manual in conjuction with these always, any DIY work is at your own risk!

This is what faces you...
Close up....the bits we're concerned with.

Purchase a timing belt. This one is made by Dayco (p/n 94423) and also fits the Alfa Romeo 6, 75, 90, 164 and GTV V6 models.

134 teeth x 25.4 wide.

You may also want to be extra careful and purchase a tool or two:

1.825.013.000 - TDC gauge holder
1.825.019.000 - Dial gauge



1.820.053.000 - Tensioner lock pin

Totally Alfa

Remove water temp sensor and water temp gauge sender connections (on the thermostat).

The manual doesn't mention this bit...drain the coolant by removing the Fan Temp Sensor on the lower left hand side of the radiator.

Disconnect the thermostat water hoses.

Disconnect both water pipes for the oil heat exchanger.
The first belt, for the aircon compressor.

Undo the centre pulley bolt and either remove or bring to the top of the slot and tighten, remove the belt.

The belt on my car was extremely tight and needed the engine rotating to assist removal.

The power steering pump.

There are two bolts in slots.

Undoing these did not provide enough movement to remove the belt.

But removing the additional two mounting bolts allowed enough movement, without undoing the rear mount.

Again, rotating the engine helped removal.

The alternator belt.

Release the bottom bolt a little, you may need to put a spanner on the rear bolt too.

Loosen the top bolt, now the alternator should move toward the engine. Remove belt.
Once all the belts are off, you can remove the crank angle sensor, just a bolt top and bottom, then pull away from the pegs.
Unclip the plug leads and move to one side.
Remove the timing covers bolts.
Look hard, they're hidden... recesses!
Remove the plug leads.

Before removing the plugs, check your plug socket fits. Sometimes there is gasket material intruding into the plug well, or the plugs are off-centre in the hole.

I had to grind down an old plug socket to permit it to fit.

You'll just need a long extension to get into five of the plug wells, but number six is under the brake fluid reservoir so you'll need a small extension and knuckle to get at it.
Remove plugs
If you have a TDC holder, screw it into number one plug hole and insert the dial gauge.

As well as relying on the timing marks present, I always like to add something to make them more obvious..."Tippex" works well.

I put a blob on the crank wheel to make the timing mark stand out.

Rotate the engine until the mark on the phonic wheel approaches the pointer...

...keeping an eye on the TDC gauge for maximum deflection.

Ensure the cam marks are at roughly 1 and 11 (see white dot near top bolts). If not, rotate the engine again, you should now be at TDC.
Remove the distributor cap to check the armature is aligned with the notch on the distributor body.

Lift the cambelt tensioner (use a lever or water pump pliers) and insert the locking tool (or suitable sized drill or other rod) to hold the tensioner in place.

Undo the two bolts and push the tensioner downwards, lock it in place by tightening the top bolt.

Inspect the tensioner carefully, they are known to leak, but this one was fine.

Now remove the cambelt, being careful not to disturb anything else. Turn the belt sideways to remove from the crank as there is a shield in the way, to protect it.

If anything moves (mine did!) then reset the various wheels to the timing marks/TDC.

Be careful of the auxiliary pulley as it moves easily and because it controls the distributor, can cause problems when the car won't start later (ask me how I know!?) have been warned!

Refit the cam belt as follows:

crank > tensioner > Auxiliary pulley > right cam pulley > left cam pulley

It'll be tight, but will go eventually.

Undo the top bolt to allow the tensioner to return and tension the belt, tighten both bolts.

Lift the tensioner arm slightly and remove the locking tool.

Rotate the engine fully, at least twice, to ensure the timing marks continue to line up.

That's the donkey work done!

I decided the clean up the thermostat apertures to ensure a good seal when the pipes go back.

All the gunge has gone.

Now you only have to put everything back in the time honoured "reverse of removal" fashion, paying particular attention to the belt tension.

Considering mine had moved(!), I connected and strobe timing light up and adjusted the timing to ensure it is exact.


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