Technical Cam sensor ????
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Technical Cam sensor ????
Yes I believe it can. Never tried myself though.
Hopefully somebody else can confirm this.
Hopefully somebody else can confirm this.
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The phase sensor is behind the exhaust camshaft pulley. Belt needs to be removed...
Well I'll be joining you soon Phil. Wife's 'B' is due 5 year cam belt change. Mileage is low so will probably be skipping the variator and water pump. Being an 2005 model later parts were of better design quality and known to be a little more reliable. I will of course check them.
I'll also look carefully at the cam/phase sensor. I gather people have damaged them doing a cam belt change so clearances must be very small.
I'll also look carefully at the cam/phase sensor. I gather people have damaged them doing a cam belt change so clearances must be very small.
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It's about using the correct tools s130, people probably damage them when they undo the exhaust cam pulley before putting the belt on. There is a special FIAT tool for this job, it is important to make note of the phase sensors location before damage occurs.
In my eyes, tippex will not suffice, instead use cam locks, a dti gauge, the tensioner tool, the cam pulley tool and the variator tool to perform the job correctly.
In my eyes, tippex will not suffice, instead use cam locks, a dti gauge, the tensioner tool, the cam pulley tool and the variator tool to perform the job correctly.
I have the tools.
Namely:
Fiat Cam Lobe Locks/BLocks : Fiat P/N: 1870697000/1 & /2
Tensioner Ajusting Key: Laser 3826
Variator Socket 24mm: Laser 3951
Sprocket Counter Torque Tool: Laser 2869
Only one I'm a little unsure of till I try is the Sprocket Counter Torque tool.
I'm not planning on changing that variator so won't need the variator socket but I bought the tool anyway.
I intend to very very accurately mark crank, and pulley positions because I'm not yet convinced about the need to slacken off the sprockets. I'll lock everything down before slacking off the pulleys and dummy fit the new belt to see how much belt manufacturing tolerances throw out the timing positions. As belts marginally stretch in use/age all the pinpoint accuracy during set will move slightly anyway.
I'll be timing the crank off the flywheel via the gearbox 0 - 5 - 10 markings. I could DTI guage it but find the flywheel markings much more accurate/easy to set TDC to.
I've lost count of the number of cam belt changes I've done. I have over 15 that I've kept and I don't keep them all. Fiat have some odd procedures and possibly too perfect procedures. Other times they get it wrong. e.g. using a DTI guage to detect TDC is NOT the most accurate way. Most accurate way is to depth guage pistons 1 & 4 or 2 & 3 till they are exactly the same. Now the crack is EXACTLY at 90 degrees. Now you use a perfect 90 deg. template to reposition the crank.
Anyway no doubt I'll enjoy doing the job.
Namely:
Fiat Cam Lobe Locks/BLocks : Fiat P/N: 1870697000/1 & /2
Tensioner Ajusting Key: Laser 3826
Variator Socket 24mm: Laser 3951
Sprocket Counter Torque Tool: Laser 2869
Only one I'm a little unsure of till I try is the Sprocket Counter Torque tool.
I'm not planning on changing that variator so won't need the variator socket but I bought the tool anyway.
I intend to very very accurately mark crank, and pulley positions because I'm not yet convinced about the need to slacken off the sprockets. I'll lock everything down before slacking off the pulleys and dummy fit the new belt to see how much belt manufacturing tolerances throw out the timing positions. As belts marginally stretch in use/age all the pinpoint accuracy during set will move slightly anyway.
I'll be timing the crank off the flywheel via the gearbox 0 - 5 - 10 markings. I could DTI guage it but find the flywheel markings much more accurate/easy to set TDC to.
I've lost count of the number of cam belt changes I've done. I have over 15 that I've kept and I don't keep them all. Fiat have some odd procedures and possibly too perfect procedures. Other times they get it wrong. e.g. using a DTI guage to detect TDC is NOT the most accurate way. Most accurate way is to depth guage pistons 1 & 4 or 2 & 3 till they are exactly the same. Now the crack is EXACTLY at 90 degrees. Now you use a perfect 90 deg. template to reposition the crank.
Anyway no doubt I'll enjoy doing the job.
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If you slacken off the pulleys, it allows you to tension the belt to full tension, you can then return to TDC, tighten the pulleys, turn the engine over two full revolutions, slacken the tensioner to the correct tension and turn the engine over again and check the cam lock tool positioning. It's essential to bed the belt in correctly.
Now assuming the original cam and crank timings were correct in the factory initial engine build then by not locking the cam lobes then if they are not moved when the old belt and new belt are changed then during tensioning they will move a very very small fraction. This is usual in almost all other cam belt changes. What I would call "Tooth Pitch Perfect Alignment".
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You simply would not notice any difference. If you want it to be as accurate as possible then by all means spend as much time that is necessary.
The method I use is the method taught to all technicians from the Fiat, Alfa, Lancia group.
I'm not disputing your line of arguement, simply stating that you may be reading a little too far into things for the engine's purpose in an automotive environment.
The method I use is the method taught to all technicians from the Fiat, Alfa, Lancia group.
I'm not disputing your line of arguement, simply stating that you may be reading a little too far into things for the engine's purpose in an automotive environment.
Thanks afroking
Question (if I may)
What keeps the camshsft pulley wheels locked to the cam shafts? Are they a tapered friction fit or are there very fine splines/undulations/ripples that ensure thet when tightened the two parts can not slip?
I ask because I know that cam rotation forces are very high and in non keyed/dowled cases then someting else is ideally required to ensure no rotational slip.
Question (if I may)
What keeps the camshsft pulley wheels locked to the cam shafts? Are they a tapered friction fit or are there very fine splines/undulations/ripples that ensure thet when tightened the two parts can not slip?
I ask because I know that cam rotation forces are very high and in non keyed/dowled cases then someting else is ideally required to ensure no rotational slip.
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Hi S130, they are a tapered fit, I believe the correct tightening torque is 120NM for the exhaust pulley bolt, the inlet pulley has four ribe bolts instead which need to be undone or removed if removing the variator (tightening 120NM for variator). I am unsure of the torque setting of the ribe bolts, sorry.
Please ask as many questions as you wish, we're all here to help!
Please ask as many questions as you wish, we're all here to help!
Well I've just about finished doing the cam belt job. Just the rocker cover, cam belt cover, header tank, battery and wheel arch liner to put back.
Now that I have done the job using the proper tools and workshop manual this is what I find:
1) Manaual only calls for the inlet cam sprocket to be relased. On later models (ours is a 2005 model), then the single sprocket bolt is replaced by four smaller ribe bolts, very similar to the traditional vernier camshaft timing spockets but with no angle markings
2) With the cams and crank locked then the belt is not a perfect fit (about a 1/4 tooth pitch) on the exhaust to crank drop. This is exactly what happens in every cambelt change I have ever done. For me this time I removed the crank lock to allow the belt/crank to nestle/mesh together. A little fiddly to do as you have to keep manual tension on the belt and gently wiggle the crank. Note the inlet exhaust sprocket just rotates into place. By moving the crank as opposed to the exhuast cam the inlet and exhuast cams are kept exactly in sync / timed with each other.
3) Now releasing the exhaust cam would get round the 1/4 tooth pitch problem but I did not do this for three of reasons (a) the later engine uses different profile cam locking blocks to the original 'B' engine (namely P/N:1870697000); (b) manual only calls for inlet to be released and (c) the different cams in the later model engine clearly have on the inlet a different adjustment mechanism to the earlier models and I couldn't but help think that the exhaust cam to sprocket fitment might not be adjustable so left it alone. Also saves risking damaging the phase sensor or phonic wheel.
Regarding not using the full tooling and just using common sense, belt & pully marking and buldog paper clips, as one can easily do on the older style engines, then I would say it is possible with extreme care and the proviso that you know the cam timing is correct from factory and noone esle has been messing. However apart from the flywheel TDC markings there are no corresponding camshaft timing marks hence the extreme caution.
Also, unlike older style adjustable fixed or simple sprung loaded tension adjusters the modern toothed adjusters are actually very fiddly in comparsing. With the older tensions you could fully back them off (if sprung like to older twin cam engines then lever them down) and then lock them in position. The timing belt was then very easy to just slip over all the components with very little risk of mving them. However with the later toothed tensioners then they are always pushing back against the belt as you try to fit it. They cannot be locked off. This make it far easier to pull on the belt and disturb the positions.
Now that I have done the job using the proper tools and workshop manual this is what I find:
1) Manaual only calls for the inlet cam sprocket to be relased. On later models (ours is a 2005 model), then the single sprocket bolt is replaced by four smaller ribe bolts, very similar to the traditional vernier camshaft timing spockets but with no angle markings
2) With the cams and crank locked then the belt is not a perfect fit (about a 1/4 tooth pitch) on the exhaust to crank drop. This is exactly what happens in every cambelt change I have ever done. For me this time I removed the crank lock to allow the belt/crank to nestle/mesh together. A little fiddly to do as you have to keep manual tension on the belt and gently wiggle the crank. Note the inlet exhaust sprocket just rotates into place. By moving the crank as opposed to the exhuast cam the inlet and exhuast cams are kept exactly in sync / timed with each other.
3) Now releasing the exhaust cam would get round the 1/4 tooth pitch problem but I did not do this for three of reasons (a) the later engine uses different profile cam locking blocks to the original 'B' engine (namely P/N:1870697000); (b) manual only calls for inlet to be released and (c) the different cams in the later model engine clearly have on the inlet a different adjustment mechanism to the earlier models and I couldn't but help think that the exhaust cam to sprocket fitment might not be adjustable so left it alone. Also saves risking damaging the phase sensor or phonic wheel.
Regarding not using the full tooling and just using common sense, belt & pully marking and buldog paper clips, as one can easily do on the older style engines, then I would say it is possible with extreme care and the proviso that you know the cam timing is correct from factory and noone esle has been messing. However apart from the flywheel TDC markings there are no corresponding camshaft timing marks hence the extreme caution.
Also, unlike older style adjustable fixed or simple sprung loaded tension adjusters the modern toothed adjusters are actually very fiddly in comparsing. With the older tensions you could fully back them off (if sprung like to older twin cam engines then lever them down) and then lock them in position. The timing belt was then very easy to just slip over all the components with very little risk of mving them. However with the later toothed tensioners then they are always pushing back against the belt as you try to fit it. They cannot be locked off. This make it far easier to pull on the belt and disturb the positions.
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If you had of undone the exhaust cam pulley bolt you wouldn't have had the problem with the belt tooth pitch being out. The exhaust pulley floats. Never mind though sounds like you got it sorted!
Are you sure this "exhaust pulley floats" applies to 2005 models? If you have done a cam belt change on a 2005 'B' then great and I'll bow to your knowledge/experience.
Most 'B's and related tech info on this forum relate to the earlier models.
I'm still intrigued as to how a single bolt securing a camshaft sprocket wheel to camshaft can adequately secure (over extended periods of time and temperature cycles) the sprocket positioning to the camshaft.
On later 'B's the securing surfaces are 3 odd inches in diameter. On the earlier models it looks like 0.75 to 1 inch max surface contact area.
Yes I know it is torqued to a high value. This is proably why Fiat changed the inlet clamping design to four bolts on a larger radius. Torgueing to 120Nm (?) and using a counter tool on the sprocket is still difficult to do without applying ANY movement in the whole cam belt chain.
Most 'B's and related tech info on this forum relate to the earlier models.
I'm still intrigued as to how a single bolt securing a camshaft sprocket wheel to camshaft can adequately secure (over extended periods of time and temperature cycles) the sprocket positioning to the camshaft.
On later 'B's the securing surfaces are 3 odd inches in diameter. On the earlier models it looks like 0.75 to 1 inch max surface contact area.
Yes I know it is torqued to a high value. This is proably why Fiat changed the inlet clamping design to four bolts on a larger radius. Torgueing to 120Nm (?) and using a counter tool on the sprocket is still difficult to do without applying ANY movement in the whole cam belt chain.
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Yes I am sure, it has about 20-30 degrees of rotation when the bolt is slackened off. Both pulleys should be slackened and rotated towards the front of the car i.e. clockwise until their stop point. This allows the correct meshing of the belt.
The exhaust camshaft pulley is a tapered fit, there is still a key in the pulley but it allows slight movement. I'd imagine 120NM is more than sufficient to ensure the pulley doesn't slip independent from the camshaft, otherwise all 1.8HGT engines as well as the entire twin-spark range would have an excessive failure rate.
Yes it can be tricky to tighten the pulley, however after experience it becomes second nature. I think the idea of it seems worse than practice.
The exhaust camshaft pulley is a tapered fit, there is still a key in the pulley but it allows slight movement. I'd imagine 120NM is more than sufficient to ensure the pulley doesn't slip independent from the camshaft, otherwise all 1.8HGT engines as well as the entire twin-spark range would have an excessive failure rate.
Yes it can be tricky to tighten the pulley, however after experience it becomes second nature. I think the idea of it seems worse than practice.
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Ah Ha!
Thanks for that info afroking.
So it is still keyed but will only allow 20-30 degrees of rotation. Now that is sensible because if that pulley were to slip then the valves would not impact that pistons and the phases sensor should immediatley throw the engine MIL light on.
Thanks for that info afroking.
So it is still keyed but will only allow 20-30 degrees of rotation. Now that is sensible because if that pulley were to slip then the valves would not impact that pistons and the phases sensor should immediatley throw the engine MIL light on.
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Not just a pretty face my friend
And today I was moving my car workshop manuals around after clearing some more space and looking my Coupe WSM at the 16V 4 cyl Coupe cambelt change instructions.
Contrary to the Barchetta manual the Coupe manual asks for BOTH intake and exhaust camshaft sprockets to be released.
Just out of interest I might fire up my Punto worshop manaul (CD) and see what that calls for.
Sometimes these offical manuals can be very confusing and contradictory.
Anyway, big plus point is the the boss (wifey) took her 'B' for a run today and gave me the proverbial thumbs up. Whirring has gone and driveabilty / performance seem perfectly OK. Will give the car a few more miles and we'll both then be giving it a good thrash to checkout top end performance.
Contrary to the Barchetta manual the Coupe manual asks for BOTH intake and exhaust camshaft sprockets to be released.
Just out of interest I might fire up my Punto worshop manaul (CD) and see what that calls for.
Sometimes these offical manuals can be very confusing and contradictory.
Anyway, big plus point is the the boss (wifey) took her 'B' for a run today and gave me the proverbial thumbs up. Whirring has gone and driveabilty / performance seem perfectly OK. Will give the car a few more miles and we'll both then be giving it a good thrash to checkout top end performance.
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