Changing belts and chain (S2) - hints and tips?
- Thread starter zcacogp
- Start date
Chaps,
Thanks for the answers. Thanks particularly to Pegasus as I didn't even know that there was adjustment of the cam timing available on the standard engine. I'd be genuinely interested in setting my engine up as described, the snag is that I only have one DTI. Does anyone in the London area have a spare one they could lend me? Or is it possible with only one? (I am guessing probably not, although haven't read the procedure in detail yet.)
One more tools-related question. The Clarks Garage procedure mentions a pin spanner - with studs pointing out of the sides to allow a certain nut (on the end of the cams, I think) to be undone. Is this essential? Can I improvise? (I am thinking of a couple of small bolts bolted firmly into some holes at the correct spacing in a sturdy piece of aluminium, cut for the purpose. Would this work?)
Oli.
Thanks for the answers. Thanks particularly to Pegasus as I didn't even know that there was adjustment of the cam timing available on the standard engine. I'd be genuinely interested in setting my engine up as described, the snag is that I only have one DTI. Does anyone in the London area have a spare one they could lend me? Or is it possible with only one? (I am guessing probably not, although haven't read the procedure in detail yet.)
One more tools-related question. The Clarks Garage procedure mentions a pin spanner - with studs pointing out of the sides to allow a certain nut (on the end of the cams, I think) to be undone. Is this essential? Can I improvise? (I am thinking of a couple of small bolts bolted firmly into some holes at the correct spacing in a sturdy piece of aluminium, cut for the purpose. Would this work?)
Oli.
JamesO
New member
I suppose easy is always relative if you already have the cams out. You do need two dti's (I borrowed mine)and they both need long noses, I used bike spokes screwed in, in place of the standard end of the dti.
The only thing I can think of that you need a pin spanner for is the balance shaft pulley bolts, if you are changing the seals and if you leave the belt in place, you can use the belt to hold it solid whilst you undo the bolt.
The only thing I can think of that you need a pin spanner for is the balance shaft pulley bolts, if you are changing the seals and if you leave the belt in place, you can use the belt to hold it solid whilst you undo the bolt.
Without the flywheel lock in theory you could put the car in gear and apply the brakes with a lever on the pedal or a willing assistant. However if your indie is going to get a bit of labour for checking the belt tension he may well loan you the tool. If not there is a good pic here http://www.arnnworx.com/Tools/944/flywheel_lock.htm and the tool for $35 but it might not make it time for the weekend!
Chaps,
Thanks again for the answers. I think a flywheel lock will be very useful and that picture was helpful - thanks Tony. Having the car in gear is never that great a solution as there is always quite a lot of slack to take up, and the idea of the engine being locked solid is quite appealing. I think I'll have a go at knocking some kind of lock up; a bit of bar, bolted across the starter aperture, with some kind of set of prongs to lock into the flywheel teeth should suffice.
Pin spanner - thanks James. I think it was for the pulley on the end of the cams, and is meant to need a fair amount of torque applied to make things happen. I'll see what I can get away with. As it is I only have one, short-nosed DTI so I won't be able to dial time the cams. Alas. I'll follow the existing witness marks when it goes back together and perhaps leave the tuning to another day. My S2 always seems to go pretty well compared with others so I am guessing it can't be far off ideal.
I am approaching the job with slight trepidation now - I am realising that while I could do a cam belt on my old Mk2 Golf in 30 minutes (including getting the tools out and opening a cold beer afterwards) this is quite a lot more of a job. There are two belts to change, quite a lot more idler wheels and a cam chain system to get to grips with. And it's not an engine I am familiar with. I'll keep you all posted on how it goes ...
Oli.
Thanks again for the answers. I think a flywheel lock will be very useful and that picture was helpful - thanks Tony. Having the car in gear is never that great a solution as there is always quite a lot of slack to take up, and the idea of the engine being locked solid is quite appealing. I think I'll have a go at knocking some kind of lock up; a bit of bar, bolted across the starter aperture, with some kind of set of prongs to lock into the flywheel teeth should suffice.
Pin spanner - thanks James. I think it was for the pulley on the end of the cams, and is meant to need a fair amount of torque applied to make things happen. I'll see what I can get away with. As it is I only have one, short-nosed DTI so I won't be able to dial time the cams. Alas. I'll follow the existing witness marks when it goes back together and perhaps leave the tuning to another day. My S2 always seems to go pretty well compared with others so I am guessing it can't be far off ideal.
I am approaching the job with slight trepidation now - I am realising that while I could do a cam belt on my old Mk2 Golf in 30 minutes (including getting the tools out and opening a cold beer afterwards) this is quite a lot more of a job. There are two belts to change, quite a lot more idler wheels and a cam chain system to get to grips with. And it's not an engine I am familiar with. I'll keep you all posted on how it goes ...
Oli.
HI there,if you not going to time the cams you do not need to refer to witness marks .when you remove the rotor arm fit 3 high tensile bolts with washers that will lock the cam drive together making it the same as a golf etc,make sure that you use top quality (snap on etc)triple square tools and "wake" the main cam bolt up as it will be tight I had my wife hold the cam with two spanners, one on the cam and one on the hex washer,when I broke mine free,all the best John.
John,
Thanks again. Good tip about locking the whole lot together. I think it was mentioned in the description on Clarks Garage as well.
When you talk about 'waking up' the cam bolt, I presume you mean the bolt on the end of the cam which holds the cam pulley on? I think this could be the one that the pin spanner was needed for. I'll be doing the job single-handed, so there could be fun and games to be had in this area ...
Oli.
Thanks again. Good tip about locking the whole lot together. I think it was mentioned in the description on Clarks Garage as well.
When you talk about 'waking up' the cam bolt, I presume you mean the bolt on the end of the cam which holds the cam pulley on? I think this could be the one that the pin spanner was needed for. I'll be doing the job single-handed, so there could be fun and games to be had in this area ...
Oli.
If you look at the pictures of my cam pulley you will see that there are no holes as in other makes of pulley to put a holding tool, the exhaust cam has shapes boult into it to place a spanner and the hex washer although it is not keyed to the camshaft will also help hold it until you free the bolt,I would try to enlist an assistant as even setting tdc using the flywheel marks require two people to do it easily,the only pin spanner needed was for removing and replacing the balance shaft pulleys and I had to pull the cam drive from the crank,unless you are going to do the oil seals at the same time you will not have this problem. It is all basic stuff but do read through the manual and do the job a few times in your head before starting. I was is no rush as it is just a toy and had the cam and distributer covers powder coated at the same time,hope this helps John.
John,
It does help, thanks. The advice about doing the job several times in your head is good advice too. I'm planning to spend this evening reading the manual before tackling the job tomorrow. Sadly it will have to be a one-person job, which will be a pain. However, I am planning to find an approximation to TDC by putting the dipstick into the spark plug hole in cyl1 and moving the crank until the dipstick reaches the highest point. This will give you a good approximation to where it should be (checking the marks on the cam pulley to ensure it is the correct TDC - for inlet not for exhaust), and I will then have a look at the back of the engine to find the mark on the flywheel.
Having said all this, is there any necessity to change the belts at TDC? Theoretically you could change them at any point in the cycle; the essential element is to make sure that all the parts are at the same point in the cycle when the belt is changed, and nothing moves relative to anything else. And, given that the belts are toothed, you can only get things out of time by units of one tooth. I'll be sure to get the engine as close to TDC as possible, and then may well make (scribe) my own marks on the various pulleys and wheels and ensure that all these marks line up as well before putting it back together. Is there any flaw in this plan? (Precautions say I will hand-crank the engine through several cycles before starting it for real.)
Not being in a rush is a luxury I don't have. Broadly, the car needs to be done tomorrow, and it needs to be drivable on Saturday. If the worst comes to the worst, I can have it taken (in pieces) to my local Indie on Saturday and throw myself on his mercy to sort the job out ... but I hope it doesn't come to that!
Oli.
It does help, thanks. The advice about doing the job several times in your head is good advice too. I'm planning to spend this evening reading the manual before tackling the job tomorrow. Sadly it will have to be a one-person job, which will be a pain. However, I am planning to find an approximation to TDC by putting the dipstick into the spark plug hole in cyl1 and moving the crank until the dipstick reaches the highest point. This will give you a good approximation to where it should be (checking the marks on the cam pulley to ensure it is the correct TDC - for inlet not for exhaust), and I will then have a look at the back of the engine to find the mark on the flywheel.
Having said all this, is there any necessity to change the belts at TDC? Theoretically you could change them at any point in the cycle; the essential element is to make sure that all the parts are at the same point in the cycle when the belt is changed, and nothing moves relative to anything else. And, given that the belts are toothed, you can only get things out of time by units of one tooth. I'll be sure to get the engine as close to TDC as possible, and then may well make (scribe) my own marks on the various pulleys and wheels and ensure that all these marks line up as well before putting it back together. Is there any flaw in this plan? (Precautions say I will hand-crank the engine through several cycles before starting it for real.)
Not being in a rush is a luxury I don't have. Broadly, the car needs to be done tomorrow, and it needs to be drivable on Saturday. If the worst comes to the worst, I can have it taken (in pieces) to my local Indie on Saturday and throw myself on his mercy to sort the job out ... but I hope it doesn't come to that!
Oli.
I would get hold of the flywheel lock before you start the job,get an assistant,set the engine to tdc and lock the flywheel,follow the service manual and use the factory timing marks,remember you have to time the balance shaft as well,I would not even think of timing it at any position using your own marks,we have gone from how to do the job properly by dialing in the cams to sticking something down the plughole for the approx tdc and making your own marks,this is not acceptable for even a poor back street garage,as for turning the engine over ,yes this will show you if any valves are touching the pistons but you could still be one tooth out and probably clear the pistons.Its your car to do with what you wish but as this job is a preventive measure as opposed to a breakdown I would cool my jets and pospone the job until you have gathered the tools,totally absorbed the manual and enlisted an assistant.It's up to you the job is quite easy but not if you are not geared up for it,do it properly and you will not have any problems,do it your way and you may get away with it but my advice for what it is worth is leave it for now,all the best John.
John,
Sage advice! Thanks. My last post came across as a bit flippant and not very clear. Perhaps I should have said that it would theoretically be possible to time the engine at any point in the cycle, but I intend to follow the factory procedure and only scribe my own marks if the existing ones aren't completely clear (although with the engine clearly at TDC.) Reading around, it sounds as if the TDC mark on the flywheel is often quite hard to see. When I did the clutch I did clean the flywheel so the mark should be moderately visible, but I will believe it when I see it (literally!)
I am quite a fan of easy-to-understand tests so would defend the dipstick-in-the-plughole procedure, but only to give an approximation. This will let you know that the engine is within (perhaps) 10 degrees of TDC, hence the marks should be almost visible, with minimal rotation of the engine necessary to get them fully into view.
I'll make the flywheel lock as the first part of the job. I've done a cam belt on a 928, which is a bigger job (V8, more tensioners, automatic cam belt tension warning system and the longest cam belt on any production car ever!) and made a flywheel lock for that without any problems. Once I have found TDC and fitted the lock then I think I'll be a bit happier.
An assistant would be lovely. But not possible; Mrs zcacogp won't be around. I may (may) be able to find a friendly neighbour, but it's not garunteed. While I would love to have the luxury of as much time as I like to do the job, several extra hands to help out and a warm, heated garage, these simply aren't possible. It's a daily driver (my only car), and the work will be done on the street, in the time available.
I'll keep you posted on the outcome. (Even if it is bent valves!) Thanks again for your input.
Oli.
Sage advice! Thanks. My last post came across as a bit flippant and not very clear. Perhaps I should have said that it would theoretically be possible to time the engine at any point in the cycle, but I intend to follow the factory procedure and only scribe my own marks if the existing ones aren't completely clear (although with the engine clearly at TDC.) Reading around, it sounds as if the TDC mark on the flywheel is often quite hard to see. When I did the clutch I did clean the flywheel so the mark should be moderately visible, but I will believe it when I see it (literally!)
I am quite a fan of easy-to-understand tests so would defend the dipstick-in-the-plughole procedure, but only to give an approximation. This will let you know that the engine is within (perhaps) 10 degrees of TDC, hence the marks should be almost visible, with minimal rotation of the engine necessary to get them fully into view.
I'll make the flywheel lock as the first part of the job. I've done a cam belt on a 928, which is a bigger job (V8, more tensioners, automatic cam belt tension warning system and the longest cam belt on any production car ever!) and made a flywheel lock for that without any problems. Once I have found TDC and fitted the lock then I think I'll be a bit happier.
An assistant would be lovely. But not possible; Mrs zcacogp won't be around. I may (may) be able to find a friendly neighbour, but it's not garunteed. While I would love to have the luxury of as much time as I like to do the job, several extra hands to help out and a warm, heated garage, these simply aren't possible. It's a daily driver (my only car), and the work will be done on the street, in the time available.
I'll keep you posted on the outcome. (Even if it is bent valves!) Thanks again for your input.
Oli.
Rich,
Thanks - that's what I am learning from reading the cam chain replacement procedure.
In which case the job is looking a bit easier, presuming I don't have to change the water pump. (I will have a spare one on hand should it be necessary, but if I can avoid fitting it I will. And this will also avoid having to make a flywheel lock, which is good news too.)
I'm feeling a fair bit happier having read a couple of the procedures in more detail now.
Oli.
Thanks - that's what I am learning from reading the cam chain replacement procedure.
In which case the job is looking a bit easier, presuming I don't have to change the water pump. (I will have a spare one on hand should it be necessary, but if I can avoid fitting it I will. And this will also avoid having to make a flywheel lock, which is good news too.)
I'm feeling a fair bit happier having read a couple of the procedures in more detail now.
Oli.
Chaps,
OK, job done. I'm not going to say how long it took me (apart from the fact that it would have been much quicker had I not done it on the side of the road, without a lift or pit, and had pretty much every neighbour, friend and passer-by buttonholing me for a chat about what I was doing, why I was doing it, what a lovely car I have, how they think the older Porsches are so much nicer than the newer ones, would I like a cup of tea, it's going to rain this afternoon - will I be done by then?, what do I think about the Panamera and had I seen one and so on ... )
The bit that wasn't done was to change the cam chain. I couldn't shift the bolt on the end of the exhaust cam, holding the cam pulley on, and hence couldn't get the cams out. It's not meant to be that tight, but I managed to ruin a spline drive socket on the end of it, and then mangled the bolt head when I applied another spline drive socket. I don't know what was going on (I don't think it's a left-handed thread, for instance), but I do know that there was no way I was going to shift the bolt, for sure. I did take the cam cover off and changed the slipper pads (top one was a bit worn, bottom one wasn't, but I changed them both anyway.) I closely examined the chain and sprockets and there was nothing at all untoward about them as far as I could see. I know that the chain was changed (by Parr, before I owned the car) at about 100k miles, and it's now on 160k, so it should have some life left in it yet. There was no sign of stretch and the cam teeth profiles looked completely symetrical to my eyes (although how valid a test this is I don't know.)
Suffice it to say that the rest of the job was indeed pretty easy. Things I would have liked to know before I started it (and now do know) are as follows:
1. The timing marks on the flywheel are hard to see through the window on the bellhousing but not impossible. (It wasn't made easier by the fact that the car was jacked up and I am quite short, and getting myself into a position to see the window was difficult!) The 'OT' mark and line are right at the front of the hole as you look through it, and there are a number of other items on the flywheel further back which are a bit confusing (bolts, teeth and so on.) However, it's not hard to get the engine to very close to TDC using other marks at the front, and swing the crankshaft back and forth with a breaker bar on the front to see the marks at the back, and to get them to line up.
2. It may be possible to do the job without removing the crankshaft pulley, but it would be very difficult.
3. You need to hold the crankshaft to remove the pulley. I borrowed (hired) a flywheel lock from ChrisG on here, who persuaded me of the need for it - thanks Chris. It made the job a lot easier, both for undoing the pulley nut and in terms of knowing that the engine was locked at TDC and wouldn't move.
4. The crankshaft pulley nut isn't that tight. 210Nm. It undid with a 3ft breaker bar without too much fuss (and I'm not large), and I torqued it back up to 210Nm with a normal torque wrench. This was part of the job that was worrying me in advance, but it proved to be quite easy.
5. The three bolts on the front of the tensioner are NOT the way to take it off. The tensioner is an assembly, and is held on by another three bolts, which are hidden behind it. These are tricky (but not impossible) to see but pretty easy to access.
6. The tensioner does almost all of the tensioning for you. When I put the new cam belt on I left the tensioner loose (i.e. didn't lock it) and hand-wound the engine through 4 cycles, before checking the tension with my fingers. It felt OK, but I gave the tensioner a tug to make it tighter before locking it off. When I started the engine, the belts were whining quite noticably, which indicated that the belts were too tight, so I slackened off the tensioner again and the whine stopped. I will take the car to an indie to have them checked properly before the end of the week.
Yes, I would do it again, and yes, I would encourage others to have a go.
I checked the water pump very carefully while the belts were off (I had a replacement pump to put on if need be), and there was no sign of any leaks, and there was only a minute amount of play on the pulley (so little I spent some time wondering whether it was really there). I was happy to leave the old pump in place.
Since doing the job I have driven the car about 20 miles (to a client site this morning), and it is very much smoother and quieter than before. Yes, I did change the oil, plugs and filters at the same time, but it is so much smoother I am wondering whether the timing belts were out by a notch before.
So, a good day out. Even if it was raining and dark by the time I was finished, and I was soaked to the skin! (And when I let the car down from the axle stands, I had to wheel the jack pretty much underwater as the car was parked in the gutter!)
Oli.
OK, job done. I'm not going to say how long it took me (apart from the fact that it would have been much quicker had I not done it on the side of the road, without a lift or pit, and had pretty much every neighbour, friend and passer-by buttonholing me for a chat about what I was doing, why I was doing it, what a lovely car I have, how they think the older Porsches are so much nicer than the newer ones, would I like a cup of tea, it's going to rain this afternoon - will I be done by then?, what do I think about the Panamera and had I seen one and so on ... )
The bit that wasn't done was to change the cam chain. I couldn't shift the bolt on the end of the exhaust cam, holding the cam pulley on, and hence couldn't get the cams out. It's not meant to be that tight, but I managed to ruin a spline drive socket on the end of it, and then mangled the bolt head when I applied another spline drive socket. I don't know what was going on (I don't think it's a left-handed thread, for instance), but I do know that there was no way I was going to shift the bolt, for sure. I did take the cam cover off and changed the slipper pads (top one was a bit worn, bottom one wasn't, but I changed them both anyway.) I closely examined the chain and sprockets and there was nothing at all untoward about them as far as I could see. I know that the chain was changed (by Parr, before I owned the car) at about 100k miles, and it's now on 160k, so it should have some life left in it yet. There was no sign of stretch and the cam teeth profiles looked completely symetrical to my eyes (although how valid a test this is I don't know.)
Suffice it to say that the rest of the job was indeed pretty easy. Things I would have liked to know before I started it (and now do know) are as follows:
1. The timing marks on the flywheel are hard to see through the window on the bellhousing but not impossible. (It wasn't made easier by the fact that the car was jacked up and I am quite short, and getting myself into a position to see the window was difficult!) The 'OT' mark and line are right at the front of the hole as you look through it, and there are a number of other items on the flywheel further back which are a bit confusing (bolts, teeth and so on.) However, it's not hard to get the engine to very close to TDC using other marks at the front, and swing the crankshaft back and forth with a breaker bar on the front to see the marks at the back, and to get them to line up.
2. It may be possible to do the job without removing the crankshaft pulley, but it would be very difficult.
3. You need to hold the crankshaft to remove the pulley. I borrowed (hired) a flywheel lock from ChrisG on here, who persuaded me of the need for it - thanks Chris. It made the job a lot easier, both for undoing the pulley nut and in terms of knowing that the engine was locked at TDC and wouldn't move.
4. The crankshaft pulley nut isn't that tight. 210Nm. It undid with a 3ft breaker bar without too much fuss (and I'm not large), and I torqued it back up to 210Nm with a normal torque wrench. This was part of the job that was worrying me in advance, but it proved to be quite easy.
5. The three bolts on the front of the tensioner are NOT the way to take it off. The tensioner is an assembly, and is held on by another three bolts, which are hidden behind it. These are tricky (but not impossible) to see but pretty easy to access.
6. The tensioner does almost all of the tensioning for you. When I put the new cam belt on I left the tensioner loose (i.e. didn't lock it) and hand-wound the engine through 4 cycles, before checking the tension with my fingers. It felt OK, but I gave the tensioner a tug to make it tighter before locking it off. When I started the engine, the belts were whining quite noticably, which indicated that the belts were too tight, so I slackened off the tensioner again and the whine stopped. I will take the car to an indie to have them checked properly before the end of the week.
Yes, I would do it again, and yes, I would encourage others to have a go.
I checked the water pump very carefully while the belts were off (I had a replacement pump to put on if need be), and there was no sign of any leaks, and there was only a minute amount of play on the pulley (so little I spent some time wondering whether it was really there). I was happy to leave the old pump in place.
Since doing the job I have driven the car about 20 miles (to a client site this morning), and it is very much smoother and quieter than before. Yes, I did change the oil, plugs and filters at the same time, but it is so much smoother I am wondering whether the timing belts were out by a notch before.
So, a good day out. Even if it was raining and dark by the time I was finished, and I was soaked to the skin! (And when I let the car down from the axle stands, I had to wheel the jack pretty much underwater as the car was parked in the gutter!)
Oli.
OK, to finish this one off. I took the car (now with about 100 miles on since the belt change) to my local indie this afternoon to have the belt tensions checked.
Chap whipped the covers off and declared the balance belt to be just fine, but the cam belt to be a bit tight. Which is interesting as I had slackened it off once already, and it was only done up to the tension from the tensioner. Either way, he slackened it off a smidge, and declared it all to be just as it should be. Which is good - I took careful note of how tight everything is so I can remember for next time!
And, best of all, after a nice chat about the job and how it wasn't that bad, and the offer of a cup of coffee (declined - mugs in backstreet garages the world over are all the same: disgusting) and the use of his toilet facilities to both have a pee and wash my hands, he didn't charge me a penny! Bravo to Tower Porsche (just sarf of tower bridge in Lahndahn). [
]
Job done. I'm happy. [] Thanks again for the advice and help.
Oli.
Chap whipped the covers off and declared the balance belt to be just fine, but the cam belt to be a bit tight. Which is interesting as I had slackened it off once already, and it was only done up to the tension from the tensioner. Either way, he slackened it off a smidge, and declared it all to be just as it should be. Which is good - I took careful note of how tight everything is so I can remember for next time!
And, best of all, after a nice chat about the job and how it wasn't that bad, and the offer of a cup of coffee (declined - mugs in backstreet garages the world over are all the same: disgusting) and the use of his toilet facilities to both have a pee and wash my hands, he didn't charge me a penny! Bravo to Tower Porsche (just sarf of tower bridge in Lahndahn). [
]Job done. I'm happy. [
] Thanks again for the advice and help. Oli.
robwright
New member
Well done Oli. After this post I think I will defo be slackening off my belt as well. I too relied just on the tensioner but now I am thinking differentlyYou should also see the state of the cups in my workshop. I actually found mould growing in one today!!! Still at least it's a sign that they are too busy getting on with the job than worrying about the state of the guest cups.
PS smoke me a kipper I'll be back for breakfast!!!
PS smoke me a kipper I'll be back for breakfast!!!
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