B20dth cambelt replacement.

[lizzard-t]

The below has been provided By Drew who is a long term member and well thaught of by each and every person .
as he quite rightly says, this conversation is going to come up more frequently as thease engines become ready for the cambelt change
so he thaught he would share his experience of replacing.

• Firstly watch this Video a few times. https://youtu.be/dAcDYCvO8tw?si=MCcx_Oss3xPeN2td
  
  I bought a kit that included the cam belt a set of idlers and a new tensioner. Crucially the set included a steel idler to replace the plastic one that wears out prematurely. (Though later cars may already have a steel idler as my Dec 2017 Insignia had)
  
  I used a standard 1/2in drive socket set, a 1/4in drive socket set a male Torx set and a set of ring spanners. A scissor jack and axle stand.
  
  Chock rear wheels and apply handbrake.
  To make it easy I jacked the car up and removed the front offside wheel then rested the car on an axle stand.
  Use a block of wood on top of the jack and support the engine from underneath.
  Remove the plastic engine cover. (You have to remove the oil filler cap first.)
  Disconnect the maf on the airbox and tuck the plug out of the way. Undo the inlet hose at the turbo and then lift the airbox out of the way, it just pulls up.
  Take note of the route of the auxiliary belt and remove it.
  Remove 4 torx screws from the wheel arch liner to allow you to fold the liner while you undo the 4 crank pulley bolts and remove the crank pulley.
  Undo the 5 engine mount bolts and the mount will lift away.
  Undo the engine mount from the engine.
  Remove the aux belt idler that sits below the engine mount.
  Remove the plastic cambelt cover it comes off in two parts, the bolts are all captive so you can't drop them.
  With the car out of gear put a socket on the crankshaft and gently rotate the engine clockwise until the timing marks on the crankshaft, camshaft and fuel pump are all visible as in the video (marked white) and photographs.
  At this stage you can if you wish use a bolt or something to lock the cam in position. (I didn't)
  Remove the belt and replace all the idlers and tensioner. Be careful not to remove the grenade pin from the tensioner.Insert an allen key in the hexagonal hole in the front of the tensioner, slacken the centre bolt and using the allen key turn the tensioner clockwise until the pointer lines up with the centre of the 'V' in the backplate. With it held in that postion re tighten the centre bolt.
  
  Check the rotation arrows on the new belt and note the 3 lines. These line up with the timing marks on the cam pulley, crank pulley and fuel pump. Fit the belt so that these line up exactly (see pictures).
  When you are confident the belt is correctly lined up pull the pin on the tensioner to release the spring that tensions the belt.
  Replace covers.
  Replace the auxiliary belt idler and crank shaft pulley, take note there is a small locating dowel.
  Replace the auxiliary belt.
  Resecure the wheelarch liner.
  Replace the engine mount, air box and reconnect the maf.
  Remove the jack from under the engine and refit the road wheel.
  
  
• 
  

[Drew]

Crucially I missed the belt tensioning bit out so I have put it here in the right order below:

Firstly watch this Video a few times. https://youtu.be/dAcDYCvO8tw?si=MCcx_Oss3xPeN2td

I bought a kit that included the cam belt a set of idlers and a new tensioner. Crucially the set included a steel idler to replace the plastic one that wears out prematurely. (Though later cars may already have a steel idler as my Dec 2017 Insignia had)

I used a standard 1/2in drive socket set, a 1/4in drive socket set a male Torx set and a set of ring spanners. A scissor jack and axle stand.

Chock rear wheels and apply handbrake.
To make it easy I jacked the car up and removed the front offside wheel then rested the car on an axle stand.
Use a block of wood on top of the jack and support the engine from underneath.
Remove the plastic engine cover. (You have to remove the oil filler cap first.)
Disconnect the maf on the airbox and tuck the plug out of the way. Undo the inlet hose at the turbo and then lift the airbox out of the way, it just pulls up.
Take note of the route of the auxiliary belt and remove it.
Remove 4 torx screws from the wheel arch liner to allow you to fold the liner while you undo the 4 crank pulley bolts and remove the crank pulley.
Undo the 5 engine mount bolts and the mount will lift away.
Undo the engine mount from the engine.
Remove the aux belt idler that sits below the engine mount.
Remove the plastic cambelt cover it comes off in two parts, the bolts are all captive so you can't drop them.
With the car out of gear put a socket on the crankshaft and gently rotate the engine clockwise until the timing marks on the crankshaft, camshaft and fuel pump are all visible as in the video (marked white) and photographs.
At this stage you can if you wish use a bolt or something to lock the cam in position. (I didn't)
Remove the belt and replace all the idlers and tensioner. Be careful not to remove the grenade pin from the tensioner.
Check the rotation arrows on the new belt and note the 3 lines. These line up with the timing marks on the cam pulley, crank pulley and fuel pump. Fit the belt so that these line up exactly (see pictures).
When you are confident the belt is correctly lined up pull the pin on the tensioner to release the spring that tensions the belt.
Now Insert an allen key in the hexagonal hole in the front of the tensioner, slacken the centre bolt and using the allen key turn the tensioner clockwise until the pointer lines up with the centre of the 'V' in the backplate. With it held in that postion re tighten the centre bolt.
Replace covers.
Replace the auxiliary belt idler and crank shaft pulley, take note there is a small locating dowel.
Replace the auxiliary belt.
Resecure the wheelarch liner.
Replace the engine mount, air box and reconnect the maf.
Remove the jack from under the engine and refit the road wheel.

[0ggy]

I have D20DTH.
What is period for replacement, saw in some documents from dealer its 120.000km/6years, is this correct?
Think 120k/6Y is for chain also...

[lizzard-t]

I would never go by manufacturers recommendations
Remember it's milage and time based whatever comes first.

And the chain can go at any time that's the weak link on this engine and we have had a few on here that have thaugh about doing the chain.too late .

[0ggy]

You think 120.000km/6year is too high or too low for belt/chain?

For the chain problem, is D20DTH also effected (as b20dth) and what to do besides listening for grinding chain noise?

[lizzard-t]

The chain deffonatly get it done as soon as money allows.
Sometimes you can hear a bit of a death rattle.
But it's not so prominent as say a timing chain rattle .
I think 120,000 km or 6 years in my mind is way too high.
Remember at the end of the day it's rubber .
It deteriorates.
I would do no more than 40.000 miles.4 years.