Timing chain slipped

So it looks like the chain has slipped! Just thought I'd start a thread and see how long it takes to fix! I have a couple of queries in CAPS below - if anyone has a couple of mins to spare I would really appreciate it.

The wife was driving our 2003 Zafira when apparently it started to rattle and then conked out. RAC man thought starter motor might have failed to disengage - but I suspected the chain. When you tried to turn it over all you got was a click and a beep - which I think is the alarm/imobiliser playing up.

I whipped the cover off and the chain has not broken, but the inlet and exhaust valves look all over the place in terms of position. (ANYONE KNOW WHERE THE CAM LOBES SHOULD BE POINTING RELATIVE TO EACH OTHER?).

I had a mechanic round yesterday who was picking up my kit car to take it away to do some work for me. While he was round he rang his mate who works at a VX dealer and it was this conversation that makes me think the chain has slipped.

The VX dealer said that when they slipped they don't usually damage the valves. I have to say, from reading a load of posts on here I beg to differ! I think it would be daft not to take the head off and check (I'LL SEE IF I CAN FIND A BOLT REMOVAL SEQUENCE FOR THE HEAD REMOVAL, BUT IF ANYONE HAS ANY HEAD REMOVAL TIPS IT WOULD BE APPRECIATED).

Assuming I take the head off, HOW OBVIOUS WILL VALVE AND PISTON DAMAGE BE?

I'm nearly done trying to remove the timing chain cover. Engine mount was a pain but I managed to raise the engine a bit to get to the last bolt. All that's left is the bottom pulley - the bolt on that does just not want to budge.

Last question - given that my cam timing is probably massively all out there is no point locking the cams before I take the chain and head off - IN TERMS OF SORTING THE CAM TIMING OUT WHEN I PUT IT BACK TOGETHER, HOW DO I START FROM SCRATCH?

Thanks in advance for any comments guys. I think I've decided to not get stressed, treat it as a bit of a project and consol myself that in a year the money I've spent will be good news for my kit car. That weighs less than 600kg and runs a 160 bhp zetec. I think a Z22se running weber 45s, a megajolt ECU with Ford coil pack and EDIS and a decent exhaust should be 180 straight off - 200bhp plus if I port, polish and cam it. Anyone got a Z22 in something other than a Vauxhall?

Dan
 
at top dead center the passenger side cam lobes(cylinder no4) lokking from the passenger side of the car should show the inlet cam lobes pointing at 1-2 o'clock and the exhaust cam lobes pointing at 11-10 o'clock.

before you take the head off compression test each cylinder then u will know which valves to be looking at, no compression meens something isn't sealed,with the head off remove the cams that way all vales should be seated, any that aren't are bent and may have damaged the valve guides too. with the head off u will see where the piston and valves have contacted any deep gouges will more likely crushed the piston rings although light gouging will more than likely have crushed them too,also depending how badly damaged the piston head is they may also need replacing.

the new timing chain comes with the timing marks on the chain so assuming the car is still TDC the chain and sprockets will all line up with just a little adjustment of the cams to allign correctly. hope this helps u out mate,if i'm incorrect on anything one of the boys will point u in the right direction.hth

martin.
 
Many thanks Martin - I wish I'd thought to do a compression test before I started taking it apart! Mind you it won't even try to turn over.

I'll check the cam lobe direction later, but assuming it is wrong do I need the engine at any particular position when the head comes off?

ta

Dan
 

BURT150

Senior Member
Tip for bottom pulley is get a couple of extention bars and a breaker bar so you can turn it out of the wing and use a axle stand under extentions to support it and hold it strait then select a gear and get someone on the brakes while you swing on the bar . there normaly hard to do so dont be scared of giving it some (y)
 

cavaddict

Senior Member
On the ones i've done, you generally find the valve guides have cracked and will need replacing (engine shop). I may have been lucky, but the light contact on the piston just leaves slight witness marks and in my case has had no effect on the rings. Actual working time is probably a day if you include the service time too. Engine shop turned the ones i gave em around in a day too. Just gotta be methodical and don't swear too much at the bolts that are hidden away. ie the 4 torx bolts holding the head on.
 
Contaminated said:
Many thanks Martin - I wish I'd thought to do a compression test before I started taking it apart! Mind you it won't even try to turn over.

I'll check the cam lobe direction later, but assuming it is wrong do I need the engine at any particular position when the head comes off?

ta

Dan

i would say that it doesn't matter too much but i would have put it at top dead center first.
 
Thanks for your help guys - I'll keep you posted. I'll have some dinner to build up my strength and give that bolt another go!
 
BURT150 said:
Tip for bottom pulley is get a couple of extention bars and a breaker bar so you can turn it out of the wing and use a axle stand under extentions to support it and hold it strait then select a gear and get someone on the brakes while you swing on the bar . there normaly hard to do so dont be scared of giving it some (y)

That worked a treat. Never would have thought of using extra extenders to get it out of the wing. On mine I left the wheel in place (on full lock) and this was exactly the right place to support the extenders while I gave it the beans!

Edit to say that initially (to get a bit more length) I used a section of 1/4 inch extender on an adapter. It bent! 1/2 inch did the job!
 
Another quick one if I may. I assume it doesn't really matter at this stage if the engine is at TDC, but how would I set TDC if the chain has slipped? No good eye-balling the cam lobes becasuse they are out. Is there a mark on the bottom pulley?

Dan
 

cavaddict

Senior Member
At this stage..just get the head off. If you were to turn the crank with a badly slipped chain you risk doing more damage. Simply remove the head and set the crank to tdc then.
 
Update again. I don't think the chain has slipped after all. The lobes look about right at TDC. Wife says rattling was under the car more than in front. I'm going to have a look at the pre-cat before I do anything else. Issue compounded by stupid alarm and imobiliser issue. As soon as I connect the battery both alams go off! Any idea what I can do to sort this?

Dan
 

Daz

Former Staff
Senior Member
Does your central locking work off the keyfob?.....

and does the alarm stop sounding if you turn the ignition on..?
 

Daz

Former Staff
Senior Member
seen ure other post just after i wrote that.,....still in thought.....
 
OK, so there is no pre cat on a 2003 Zafira then! Still not found any real issues - bolting it back together now. If it becomes melted metal when I turn the key so be it :eek:
 
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