Armed with a Hyanes manual and a cambelt kit from Vauxhall I decided to have a go at changing the cambelt on my wife's Corsa 1.4 16v (X14XE engine).

Spent ages lining things up, turned it over by hand twice and checked it all lined up again.

Started it and it did nothing but mis-fire.

So I checked the alingment and the tension again, the marks were spot on and the tensioner was in the "new" tension position.

Started it again and it misfired and idled really badly.

Decided I must be doing something wrong so took it all off and started again, this time I got a friend to check the alignment and tension as per the Haynes manual - all was good.

Started it and the thing reved its nuts of all on its own - racing towards the redline, so we had to turn it off.

As you can tell I'm not best pleased with my day's work!

Any ideas?

My wife wants to use the car in the morning LOL!

The lines meet in the middle on the 1.4 16v dont they?

Are you using the bottom pulley to set the crank up?

Yes, I'm aligning the mark on the gear at the bottom to align it with the mark on the inner cover bit that sits behind it (as per Haynes). I cant use the mark on the bottom pulley because when its in the car you cant see where the mark is on the block.

Yes, the lines meet in the middle.

Is the throttle body back on its stop? Is the cable slack when the throttle is closed?

Problem solved via MSN Thanks Ross - it was an air leak

However, it now sounds rather "tappety" if you know what I mean. Almost has a diesel clatter.

With the bonnet open it sounds like it is coming from the back of the engine in the middle somewhere.

Does that engine have hydraulic tappets?

Does that engine have hydraulic tappets?

yes

that was my immediate thought, but just changing the belt should cause the hydraulic lifter to bleed down and start rattling, they normally keep thier tension for weeks

Problem solved via MSN Thanks Ross - it was an air leak

However, it now sounds rather "tappety" if you know what I mean. Almost has a diesel clatter.

With the bonnet open it sounds like it is coming from the back of the engine in the middle somewhere.

was just about to say air leak , obviously waaaaaay too late :(