Snapped chain...

kmbrad

Hi all.

What a great site. I visited yesterday for help in indetifying a slight tapping noise from the chain cover.

I've been a mechanic for 6 years but not that familiar with the z22se engine.

My dads friend is a sales manager at the local Vauxhall dealership and I was taking it down to him to get it diagnosed. I made it half way to the garage before the chain snapped.

I've towed it back now to my garage and I'm going to start a strip down.

Any help / tips would be appreciated.

I'll keep you updated of my progress.

Karl

Matt

Hi Karl, welcome to the site. Sorry to see your first post is one about a snapped chain. Hope too much damage wasn't done.

kmbrad

Thank you Matt.

I was just exiting a roundabout when it happened doing around 20mph. Hoping the head hasn't received any damage. But as the chain is snapped I cannot do a compression test. So I'm undecided whether to strip the head down, or put the new chain on, then see how she runs.

I'll let you know how I get on.

vectra2k9

kmbrad said:
Thank you Matt.

I was just exiting a roundabout when it happened doing around 20mph. Hoping the head hasn't received any damage. But as the chain is snapped I cannot do a compression test. So I'm undecided whether to strip the head down, or put the new chain on, then see how she runs.

I'll let you know how I get on.

the exact same thing happend to me mate literrally strip the head down and see the damage shoould only take a hour or so

kmbrad

Took the chain cover off today, and found no chain.

Took the rocker cover off and found the two rockers on the exhaust side on cylinder 4 were missing. Found them laying next to the camshaft. They don't appear to be damaged. Thought the valves must have been hit so removed the cylinder head.

Will strip the head down tomorrow and have a close look.

I have noticed a crack in the exhaust manifold. Not sure what to do about that yet.

Took best part of 3 hours to get the head off (on axle stands, not ramp). Gotta say, I found the hardest part removing the plugs from the injectors.

kmbrad

vectra2k9 said:

kmbrad said:
Thank you Matt.

I was just exiting a roundabout when it happened doing around 20mph. Hoping the head hasn't received any damage. But as the chain is snapped I cannot do a compression test. So I'm undecided whether to strip the head down, or put the new chain on, then see how she runs.

I'll let you know how I get on.

the exact same thing happend to me mate literrally strip the head down and see the damage shoould only take a hour or so

Vectra2k9, I was looking at your previous posts. You sent your head away to get done? What did they do and how much did it cost you?

rik1083

you can remove the rail with the plugs still in then unplug them

kmbrad

rik1083 said:
you can remove the rail with the plugs still in then unplug them

Now he tells me. 😃

rik1083

just watch that you don't lose an o-ring in the inlet port with standard injectors, there's barely anything holding them on, unlike z20let type ones

kmbrad

Will check the injectors now as the heads going away later today.

Thanks for the heads up,

daaaaavek

kmbrad said:

rik1083 said:
you can remove the rail with the plugs still in then unplug them

Now he tells me. 😃

hehe .. you always learn more by doing something the hard way first!

karl, sorry to hear about your snapped chain. care to post some photos of the damage and what you find .. ? i've been fortunate not to have the chain problem with my engine, and I keep reading horror stories but have never eyeballed what exactly the damge looks like..

kmbrad

Thats always the way isn't it. lol.

Damage, hmmm where do I start?

Found a guy who will recondition my head at what I believe a reasonable cost. It was collected today by courier and should be a 2 - 3 day turn around. Confident not too much wrong with that. Two rockers on both 7 & 8 inlet valves slipped off and I think just the two inlet valves on that cylinder damaged.

So today, with the head gone I took the bottom chain cover off. Once removed I found more bad news.

The bolt holding the oil nozzle jet inplace has sheared and the nozzle jet itself is in three parts. Also sheared was one of the bolts holding the cam chain guide rail. Luckily, both of the broken threads have came out with not to much work involved.

I'm taking the sump off tomorrow to check if any debris has landed in there.

I also got price on parts from local Vauxhall dealer to me. Then I called a friend who's a sales manager at another dealership and he is seeing what prices he can get for me.

I think I need, the balance chain kit and cam chain kit. The guy who is reconditioning my head has quoted me for a head gasket set and head bolts, alot cheaper than Vauxhalls.

It continues......

BURT150

Thats a bad one :eh: sorry to hear about that. These things are sent to try us and all that!

Looks like the chain took out everything in its path then!

Best to do both chains and might be worth looking at a z20net balancer chain tentioner(spring loaded instead of oil pressure)

timing cover gasket, bottom pulley seal and bolt to add to the list too :thumbup:

kmbrad

Hi Burt

Well I'm gonna buy both chain kits as all the guide rails are shot.

Both the sprocket gears on the crank shaft have teeth missing too.

I need to find out whats included in the chain kits first before I start ordering all the parts.

I'm taking the sump off tomorrow to have a peek in there. That should all be OK, but if there is anymore damage, I'll write the engine off.

si_c1978

definately try and pick up th z20net tensioner like burt says!

kmbrad

whats the z20net tensioner when its at home?

si_c1978

its the 2.0l t lump out of the signum and vec c the blocks essentialy the same as the z22

BURT150

The timing chain kit includes a chain, 2 cam sprockets,crank sprocket, all the guide rails and bolts and a tentioner and oil jet(5mm oil jet).

Balancer chain kit is chain, crank sprocket, guide rails, bolts and tentioner.

Ive seen some kits with all the sprockets and some without so yea i think you'd be right in checking first,

The z22se balancer chain tentioner has been known to fail. It uses oil pressure to take the slack in the chain so a good replacement is the z20net tentioner because its a spring loaded job and holds its own without oil pressure.

Ill see if i can find a part no.

you can still use the new z22se tentioner but the you have another option for total peace of mind, totaly up to you tho.

BURT150

Hopefully it'l just be the top end then. I got lucky with mine it started getting noisy when cold so changed both chains and bin fine ever since.

z20net chain tensioner:GM part no. 55352127

kmbrad

Thanks Burt, I'll add that to my list of ever ending parts.

I drained the oil earlier and it looked as clean as it did when I changed it last month. So many broken parts in the timing chain area and I hadn't located them all. So I took the sump off earlier, didn't want to as they don't have a gasket and in my experience, trying to seal to metal faces with just sealant never works. I'm glad i did though...

Cleaned it thoroughly and tried to work out where the bits came from. I'm missing a couple of teeth off both crankshaft sprockets and bits of plactic from the guide rails. I've found all of that, but I've found a copper / brass bit with a spring? I'm assuming it's part of a tensioner?

I've washed down the whole side of the block where the timing chains run and I'm now ready to do the balance chain.