Hi all, I recently replaced a timing belt on a 156 Alfa 1.6 litre. This was my first time doing an Alfa, I would have done this job on other vehicles several times . Here are some notes that may be useful to others attempting the job for the first time.
The only odd ball tools I needed were the cam blocks to lock the cams in the correct position. You could mark the cams against the head with tippex but there is a chance you might be a tooth out. Buy the blocks. You will need torx tools. I had recently bought a kit like an allen tool set. There is no Haynes manual available but there is an “e-learn” maintenance manual CD avail on the net. It takes a bit of getting used to but it does have detailed procedures if you can find them. The timing belt replacement procedure is good .
If the variator is worn ( diesel knock on start up ) it is a good time to replace it . Also water pump replacement is recommended and ignition plugs if due.
1) Crack the wheel nuts on the front r/h wheel before putting the car up on axle stands at the front.
2) Remove the wheel, dust cover over the crank shaft pulley, and the top cover over the engine .
3) Un-tension the aux drive belt by putting a long ring spanner on the tensioner pulley nut and pull against the tension. Remove the belt when the tension allows it to come free. Check the condition of the belt , get a new one if needed. It`s not difficult to replace anyway. Remove the aux belt idler pulley. ( I had some trouble with this later ) Remove the crankshaft pulley. It is held on with four torx bolts. You can hold the crankshaft from turning by holding the central nut. Remove the timing belt cover .
4) Disconnect the ignition coil harness, the plate it screws to, and two pipes that connect to the black plastic cam cover. It would be a good idea to have a new rubber seal for refitting of the cam cover. Mine had evidence of reuse and gasket sealer and I had to do the same.
5) Remove the No. 1 cyl ( nearest the cam belt ) large plug and use something like a knitting needle ( or a long thin rod ) inserted in the plug hole to determine TDC. Be careful not to allow dirt to enter the plug hole. Turn the crankshaft using the central bolt and stop when the needle / rod stops rising. Check that both valves on no. 1 cyl are closed ( cams not depressed ) and the cam blocks should now fit in the cam bearing cap locations as follows ( go another 180 deg if not in the right place ) . You will have to remove the caps first and use the bolts to keep the blocks in place. The 3rd bearing cap from nearest the cam belt on the camshaft nearest the w/screen and second from r/h bearing on the camshaft near the front bumper.
6) The cams are now locked in place. I had some problems with the cam block / bearing cap bolts., more on that later. The crankshaft pulley locator dowel now points directly downwards in line with the engine. The crankshaft is not locked in place. Slacken the cam belt tensioner nut, a new lock nut would be a good idea, it did not come with the kit. I reused mine. The cam belt should come off easily. Direction of rotation arrows point towards the front of the car. I removed the tensioner and the idler pulley as I had new ones from the kit.
7) I removed the water pump , its another timing belt idler pulley . It is a good idea to replace it when replacing the belt. Two bolts hold it in place. There is a third smaller bolt on it that holds a plastic part of the timing belt cover attach. Remove the two bolts that hold this part in place. When you remove the two bolts that hold the pump in place , coolant comes out of the holes ( strange ) Be ready to catch it below . I used a basin. I removed the pump and allowed the engine to drain. My plans to flush the system did not work as it was too difficult to remove the crimped hose clips on the rad lower hose. Pouring water in the coolant tank just it to made it pour out the water pump hole without disturbing the coolant in the bottom half of the engine / rad. I fitted the new pump with the o-ring and plenty of gasket sealer on the o-ring area and the retaining bolts. There was evidence that this had been done previously . Refit the small plastic cam belt cover attach part.
8) I fitted the tensioner and idler pulley as supplied in the continental timing belt kit. I checked the timing belt was the correct 163 toothed version as apparently there is a 166 toothed version also. Even with the tensioner fully slackened it was fiddly getting the belt on . The crank shaft had to be turned to keep a pull on the belt coming off the front cam and ensuring it ended up in the right place ( locator dowel facing directly downwards as before ) I had marked everything with tippex before removing the belt . It took a few goes to get the belt on with the crank in the correct place.
9) The tensioner has to have its spring loaded pointer pointing to a hole when the belt tensioner is correctly tensioned. E-learn shows a special tool for this but levering with a screw driver ( not against the belt ) worked fine. When I was sure the belt was correctly positioned and the tensioner adjusted, I removed the cam locking blocks and replaced the cam bearing caps ( in the same positions and orientation that they came off ) I then discovered that the problems I had using the bolts to lock the blocks in place was because they had been overtightened previously and the threads damaged. Luckily there was enough thread left to fit and tighten. I had that terrible feeling the they could strip further if abused.
10) Two full turns of the crankshaft pulley proved the valves weren`t going to hit the pistons but also showed the tensioner needed further adjustment. That was done and two more full turns and it stayed with the pointer pointing at the correct hole as per e-learn. Belt fitting complete.
11) It`s a good time to replace the spark plugs if due ( approx 80 euro ) . Spark plug, ignition coil plate, ignition coils, ignition coil harness, black plastic cam cover ( seal cleaned and gasket sealer use on it also ) and the two pipes refitted also. Some of the ignition coil connectors did not lock in place so small black tywraps sorted that. Timing belt cover refitted, Crankshaft pulley refitted ( locktite on the bolts ) Aux belt idler pulley refitted……problem…..it wouldn`t tighten ! Luckily a longer bolt from the biscuit tin bolt collection with a few washers picked up the remaining threads and would tighten …..phew….lucky break. It`s obviously easy to strip threads on these alloy engines.
12) Aux belt fitted, wheel arch cover , r/h wheel ( tighten the bolts when on the ground ) top up the coolant and fit the engine top cover . Hold your breath and turn the key……it starts and runs smoothly and quietly. A test drive confirms all is well, no leaks and performance as expected……….a job well done .
I hope I haven`t missed anything but it`s my experience for what it is worth. It doesn`t mean it is correct. ( This is the disclamer part )
…..Best of luck on your job……………….regards ..Dannyboy