So I don't often post on forums but felt this may be beneficial for anyone embarking on this journey. So a bit of history. Back in 2015 my daughter was turning 21. So I figured I would be a good dad and buy her a brand new car. The local vauxhall dealer were having a special and when I found that the 1.0 had a cam chain I thought great here is a car that will last her for years trouble free. I mean I qualified as a mechanic many moons ago (although I am no longer in the trade) and every cam chain car I had hitherto owned or worked on had been Uber reliable. Alas I should have done more research because as I now know that particular theory was soundly shattered by this series of engines and I believe the 1.2 and 1.4 suffer the same. Anyhow what I learned\n\n1. Change the oil EVERY 10K miles maximum and the filters every 5K. The filters have a bad habit of collapsing causing oil starvation and premature chain wear. The tensioner is a stupid hydraulic system with no return arrester. In other words when the hot oil drains overnight there is none left in the tensioner in the morning meaning that each one of those cold starts is done with effective a slack chain. "F***ing STUPID idea.\n2. Use the correct grade and spec oil. For the reasons above, slightly too viscous (even within the same 5W30 band) seems to result in collapsed filters and so on\n3. When you come to change the cam chain make sure you buy a full kit and ensure you have the proper timing tools. I am fortunate to have a fully outfitted garage with more tools than I will ever need but you probably won't so be prepared. BUY A HAYNES MANUAL !!\n4. Buy a new water pump WITH new gaskets !!!\n5. Drain the coolant\n6. The instructions say remove the sump. DO IT, do NOT read (as I did) these stories of guys that managed to do it without taking off the sump. I am sure they managed but it is just not worth the hassle. Drop the cross member bracket under the exhaust, remove the bolts from the flange, take off the rubber supports and let the exhaust gently fall to the ground.\n7. Remove the sump (OBVIOUSLY drain the oil first). You WILL need a rubber (MUST BE RUBBER) mallet to encourage it off. Be careful, there are two hidden recessed bolts near the bell housing and there are three bolts that go through the bell housing\n8. Remove the spark plugs and cam cover before anything else and get the number one cylinder at TDC on the compression stroke, using the timing tools as described in the Haynes Manual.\n9. Remove the TDC locating tool from it locating hole and loosen the crank pulley bolt before you go any further. Trying to do this with the right hand engine mounting bracket on won't be a good idea. I use a sacrificial 14cm screw driver with a 5mm diameter shank on which I have bent the first 3-4cm at 90 degrees. I then wedge this into the teeth of the flywheel just above the right hand drive shaft. to lock the flywheel. Make sure you have a good fitting TORK socket and if available an impact drill. If not use a ling power bar and get someone to push against the head (using a piece of wood or something to protect their hand, so as to ensure the socket doesn't come off. Give a series of sharp tugs which is more efficient than a long gradual pull.\n10. Then follow the instructions as per the manual.\n11. When you get to the valve timing part, this is where I found the manual to be erroneous. They state you must remove loosen and lock the cam chain tensioner. I found that by having slack in the chain it was very difficult to time up the valve timing perfectly so that after two 360 cycles you could easily put the setting back back into the slots on the camshafts. Having tension on the chain meant that the pulleys were less likely to move when I was tightening up the bolts. ALSO I found that inserting the TDC locking tool rotate the crank VERY slowly when you are just about at TDC and apply pressure the whole timing until the pin goes fully in but go no further. You will find that you can still go a fraction of a millimetre after it is fully in. This fraction equates to enough of a degree on the camshafts to knock out your perception of the cam setting.\n\nAnyhow hope someone will find this useful, hope I never have to do it again and once I get rid of my Zafira and my daughter gets rid of her Corsa I will never buy another Opel/Vauxhall/Peugeot or whatever they are calling themselves in the future.\n\nGood luck.