Timing Belt Change - A tinkerer's tale
There is some good advice on the web, not least on Alfaowner about DIY timing belt replacement. Having just done one, I thought I'd add a few points that may not necessarily be covered.
Note this refers to a 147 1.6 TS with air conditioning. This post isn't supposed to be instructions for fitting the belt, just some additional advice; apart from postings on the web, eLearn is essential for this task.
First, the tools you definitely need are the cam locks, longer bolts to fit these in place of cam caps, tensioner setting tool, a tool to hold the exhaust cam pulley while you loosen/tighten the nut, a torque wrench or wrenches covering a range from about 15NM to 130NM, two offset combination ring spanners 15mm/16mm and 19mm/19mm. On the 1.6 you don't need the dial gauge and fitting tool, but I believe them to be essential for 1.8 and 2.0 engines. I'd definitely recommend getting a set of RIBE keys from Machine Mart for just under £20. The bolts you need to undo to get to the cam caps are probably okay done with a Torx key, but those holding pulleys, especially the ancillary belt pulley, will definitely need the right tools (if they were as tight as mine). I was going to get the full set of specialist tools from Totallyalfa, but the shop has been down for several weeks and I didn't want to wait. I got the cam locks from Shop4parts, tensioner tool and M7 x 45mm bolts from Ebay, pulley holding tool from Amazon and the two spanners from Halfords. A final item that will be handy is a long luggage strap with a self-locking buckle.
The 1.6 has timing marks on the ancillary belt pulley and timing belt cover. It is much easier to use these to find TDC than to faff around with the dial gauge. After removing the ancillary belt (first remove a plastic cover that runs above it as it crosses the timing belt cover - this is held by two hex bolts that run through the belt cover and a 10mm nut just above the A/C pump), set the engine to TDC (turning the bolt on the bottom pulley clockwise until the marks line up - check that the inlet cam lobes on cylinder 1 (visible through oil filler) are facing towards the back of the car and, if not, turn it through another full turn and they will be. Undo the four RIBE bolts that hold the pulley on. As mentioned, these were very tight; I had to fit a 19mm socket to the nut and jam the handle against the driveshaft while loosening the bolts with the RIBE key fitted to a breaker bar. Once the bolts are out, work the pulley gently backwards and forwards until it comes loose. I levered it away from the engine a little (and very carefully) with a crow bar at the bottom, then tapped it back with a rubber mallet; it then cam off easily enough. The next job almost had me give up - getting the ancilliary belt idler wheel off. Here you'll need the 15mm ring spanner and a lump hammer. It's very tight, but will come off. the nut is accessed by removing a little plastic cap.
replace the pulley, ensuring it is lined up (there's a small key) and check engine is still at TDC. Remove it and remove the belt cover (3 x hex bolts). Use paint or the traditional tippex to mark TDC at the crank pulley.
The 19mm offset ring spanner is used for turning the engine over, acting on the nut on the crank pulley. You can do this with a socket wrench if you can lock it both ways; if not, you have no control of the wheel, which will spin forwards when it passes TDC. Removing a plug from each cylinder makes it easier to turn the engine over, but, without the additional pressure, it's more likely to move if disturbed.
For fitting cam locks, removing belt, loosening pulleys, replacing tensioner, idler and belt, refer to other posts and e-Learn.
Be very careful when loosening/tightening the exhaust cam pulley. I was careful to avoid the cam position sensor behind it (at about 8 o'clock) with my locking tool, however I managed to distort the track on the back of the wheel and the track took out the sensor. If you put everything back together and then find you've buggered the sensor, it all has to come off again and you're into about £80 in parts. Make sure the locking tool is firmly held against the wheel and isn't pressing on the edge of the track. There's a fair range of torque for the nut and you don't need to tighten it to the top of the range if you are worried about the track.
e-Learn advises a certain order for fitting the belt, with it going onto the water pump pulley last. I couldn't do it that way working with the engine in the car, so slipped it onto the idler pulley last. Do turn the loosened cam pulleys clockwise when you run the belt over them and have the tensioner quite loose. It took a few tries to get the belt on without moving the crank pulley off TDC. Make sure you have the belt on the right way before you go any further.
I couldn't get the tensioner adjusting tool onto the car with the tensioner assembly in its loose position. I put a 1/4 drive extension into the hole, slipped a screwdriver in beside it and turned it 90 degrees, then tightened the pulley nut. It won't be correctly set, but this gives you enough space to get the tensioner tool in to do it properly. The way the tensioner and tool work is hard to explain, but you'll get the idea when you see it. Follow instructions on eLearn to set tension.
So, belt is on and tensioned, cam locks removed and cover, coil packs and engine cover back on, belt covers, pulley and idler back on and the last task is refitting the aux belt. I brought the belt into the house and left it on top of a radiator while I was working to keep it supple. Run the belt around all of the pulleys and tensioners except the a/c compressor. run the luggage strap through the 16mm end of the 15mm ring spanner and bring the end of the loop above the engine. Loop it around something (top of the dipstick for example) to stop it dropping. Working under the car, put the 15mm end of the spanner onto the tensioner nut with the spanner as far clockwise as you can fit it. Working above the engine, get youself inside the loop in the strap and tighten it so your body is as low as you can comfortably get it. Then lift yourself up as far as you can. It the loop was small enough, the spanner should go all the way around and the tensioner be fully compressed. holding your position, work the belt over the a/c pump pulley, then gently lower yourself, slip the strap off your body and go for a soak in a Radox bath.
If working outdoors, try to keep the engine covered while the cam cover is off. Before putting the cover back on, wipe all of the cam lobes with a clean piece of kitchen tissue to remove any dust that may have settled on them. Check around for dust, bits of gasket material or bits of latex glove and clean them away. Lastly before refitting the cover, dribble a little clean oil on to the cam lobes. I actually used 3 in 1 as it's easiest to apply and you only need a drop, though I suppose one should use engine oil really.
Use Loctite on the tensioner bolt, idler pulley bolts and water pump bolts if you change the pump. Use copper grease between the ancillary belt pulley and crank pulley.
The belt change is a straightforward job if all goes well. I found that the hardest parts of the process were to do with the ancillary belt - removing the idler pulley and refitting the belt. I doubt I saved any money by the time I'd bought all of the tools and replaced the pulley and sensor I buggered, but doing this myself was as much about the satisfaction of achievement as a money saving exercise.