Technical Crankshaft timing out?

[maffp]

Hi!

I'm currently working on a head gasket change on a friend's Bravo SX 1.2 16V (51 plate). I purchased the camshaft locking bolts with two piston height gauges. I turned the crankshaft until the piston heights were similar then just turned a bit each way till the locking tools would go into the camshaft grooves and tighten up to lock the camshaft in place.

However, once the camshaft was locked I noticed that the piston gauges aren't exactly the same. There's about 3mm difference (pistons 1-2). I tried pistons 1-3 and they were the same.

The timing belt is off, does this mean I need to make an adjustment to the crankshaft?

Many thanks,
Maff

 

[L33 HCX]

Hiya Maff.

Just done this on mine, yeh you just need to turn the crankshaft sprocket until the gauges are aligned.

Also a bit of a heads up, when you put the belt back on you need to loosen the nut on the camshaft sprocket to stop the tension of the belt turning the engine over and unsyncing it again. I suggest using a sprocket locking tool if you've got one as to much pressure on the cams my damage them.

I learnt this the hard way! haha.

 

[maffp]

Hi L33,

Cheers for that... thought it must be the case but wanted to check it wasn;t part of some weird Fiat timing or summat!

I've fashioned a camshaft sprocket holding tool with two pieces of steel and some bolts (as per Haynes manual tip) so hopefully I won;t go knackering it.

I'm just very paranoid cos the last time I changed a head gasket was on my astra when I was 17 (13 years ago) and when I fired it up the camshaft snapped! I didn't have any locking tools back then though so I think I must have got the timing miles off or summat! :bang:

 

[L33 HCX]

Yeh its always a nervous time when doing anything with the engine.
Just get it all setup up and then turn the engine over by hand a few times, you'll know for sure then if somethings out.
Then when you feel pretty sure, fire her up, but be ready to knock her off straight away incase.
Another hint, for about a day after my tappets were quite noisey, possibly a combination of the re-timing and oil change. This soon silenced though and shes now good as new.
All the best.
Lee