OP
OP
Latest update on this one... Took the beast for a test drive... and the engine wasn't sounding too great, so..... while I don't need the car much... I decided to take the cam-belt off again for another look at it.
First thing I dealt with was the TDC sensor countersunk screw. I had recently bought myself a pukka chisel from Wickes @ £7... since it saves my screwdrivers when I want to apply some "persuasion" to stuff..
Anyways, it's sharp and it's "hard"... so I used it on the outer edge of the screw to put a notch into it. The chisel ate into the screw head fairly easily... and at the same time, the force of me tapping it freed up the screw. I used the chisel to slowly rotate it past the point where the corroded threads were out of the hole... and then took it out by hand. Result!
A new hex-head screw was too tall to clear the camshaft sprocket but a regular M6 x 12mm hex head bolt *just* fits under it. So that's done. TDC sensor will be easy to remove next time.
Next off, the camshaft sprocket. I noticed that with the crankshaft locked, the marker on the sprocket was *almost" aligned with the pointer on the head. It's never aligned, nor "almost" aligned.. it's always had the appearance of being one tooth out...
I was initially pleased that it's all lining up at long last... even though it ran fine before, when it wasn't... and now it's a bit rough.
I removed the sprocket so I could re-seat it.. and I took notice this time, that the sprocket has a lot of "slop" on the camshaft. I think in the past I always just replaced the sprocket so that it appeared one tooth out (which works) but last time out I rotated it as far as I could to get it closer to the marks lining up.
It turns out that the key on the back of the sprocket seems to have been mashed up at one time in the past.. probably put onto the cam in the wrong place (maybe by someone trying to line up the marks) and then tightened up against its will, till the cast "key" fractured. Without square shoulders, the damaged key allows the sprocket to rotate slightly on the cam, until it's tightened up.
In the past I've always lined it up by eye (setting the sprocket mark "one tooth out", how it came off), so never really given it any thought, even though I realise I did notice that it was "sloppy" and that maybe it should be more precise.
So... the next job is to re-set the sprocket by eye "one tooth out".. which is probably not really one tooth out... (it could be the pointer isn't straight) or maybe it is but the car runs great like that, so I'm not going to insist...
But it may be an idea to get a new sprocket with an undamaged key. The sprocket can't rotate, since there's enough key left to locate it into the camshaft slot.. but it can move backwards and forwards, once located.. just a few millimeters but that's probably what's making it run a bit ginger at the moment.
Does anyone knoe where I might find a cheap/good sprocket? Otherwise I can persvere/repair mine, so that it's more how Fiat intended.
Ralf S.
First thing I dealt with was the TDC sensor countersunk screw. I had recently bought myself a pukka chisel from Wickes @ £7... since it saves my screwdrivers when I want to apply some "persuasion" to stuff..
Anyways, it's sharp and it's "hard"... so I used it on the outer edge of the screw to put a notch into it. The chisel ate into the screw head fairly easily... and at the same time, the force of me tapping it freed up the screw. I used the chisel to slowly rotate it past the point where the corroded threads were out of the hole... and then took it out by hand. Result!
A new hex-head screw was too tall to clear the camshaft sprocket but a regular M6 x 12mm hex head bolt *just* fits under it. So that's done. TDC sensor will be easy to remove next time.
Next off, the camshaft sprocket. I noticed that with the crankshaft locked, the marker on the sprocket was *almost" aligned with the pointer on the head. It's never aligned, nor "almost" aligned.. it's always had the appearance of being one tooth out...
I was initially pleased that it's all lining up at long last... even though it ran fine before, when it wasn't... and now it's a bit rough.
I removed the sprocket so I could re-seat it.. and I took notice this time, that the sprocket has a lot of "slop" on the camshaft. I think in the past I always just replaced the sprocket so that it appeared one tooth out (which works) but last time out I rotated it as far as I could to get it closer to the marks lining up.
It turns out that the key on the back of the sprocket seems to have been mashed up at one time in the past.. probably put onto the cam in the wrong place (maybe by someone trying to line up the marks) and then tightened up against its will, till the cast "key" fractured. Without square shoulders, the damaged key allows the sprocket to rotate slightly on the cam, until it's tightened up.
In the past I've always lined it up by eye (setting the sprocket mark "one tooth out", how it came off), so never really given it any thought, even though I realise I did notice that it was "sloppy" and that maybe it should be more precise.
So... the next job is to re-set the sprocket by eye "one tooth out".. which is probably not really one tooth out... (it could be the pointer isn't straight) or maybe it is but the car runs great like that, so I'm not going to insist...
But it may be an idea to get a new sprocket with an undamaged key. The sprocket can't rotate, since there's enough key left to locate it into the camshaft slot.. but it can move backwards and forwards, once located.. just a few millimeters but that's probably what's making it run a bit ginger at the moment.
Does anyone knoe where I might find a cheap/good sprocket? Otherwise I can persvere/repair mine, so that it's more how Fiat intended.
Ralf S.
