Astra coupe 2.2 Cam chain issues

sigibbons

Hi im new here i have a 2.2 bertone astra coupe which im rebuilding it looks like the cam chain tensioner has snapped (the plastic straight one towards the front of the car, not the banana shaped metal one) bits have gone everywhere so im assuming i can buy a new tensioners peice and time the engine up and all will be well??

Upon inspection of the other engine chain (dont know the name for this one) it seems slack at the moment, i assume when the engine starts up it tensions up??

Thanks, Simon.

vocky

you must replace the complete camshaft timing set - £95

if the balancer shaft chain is slack that must be replaced too - £105

they don't auto tension, so if slack = duff

cheaper than an engine rebuild !

sigibbons

What does the camshaft timing set include and why must it be replaced?
Oh right the other chain is a balancer chain! Thanks, briefly does it balance the timing chain or something?

I did see a forum member selling these kits who is he and where do i find him?

Oh and is there some sort of guide to replacing timing and balancer chains?

Thanks very much, Simon.

baldie87

the kit includes everything you need to replace the chain apart from the gaskets for the chain cover

tensioners
chain
nozzle
etc..

sigibbons

So why cant i just replace the tensioner on the timing chain?
And what does it mean has happened if the balancer chain is slack?

Thanks

vocky

basically when the tensioner breaks it damages all the guides and the chain + sprockets, the balancer chain is slack because a piece of the broken tensioner has damaged that chains tensioners

failure to replace both chains will lead to a total chain failure and a new engine = £2000 !

the chain timing is out and the chains have to be removed to reset the timing, if it wasn't required we wouldn't advise changing them, but you do need to replace them 🙁

sigibbons

So if the balancer chain has a hydraulic tensioner surely that tensions up when oil is forced into it? So the chain should be slack when not running???

How do the sprockets and chain damage then?

I dont want to sound as though im not listening but i would like to know reasons why these things are a must? It just looks as though im replacing parts which dont look damaged anyway?

Thanks very much!

vocky

the balancer chain still has tension without oil pressure, the internal spring does that, oil pressure just makes the tensioner much stronger as when the engine is running the internal spring isn't strong enough.

the same with the cam chain tensioner, it works exactly the same way

for either to have no tension means something is broken, for £100 a chain set it isn't worth risking

george

sigibbons said:
What does the camshaft timing set include and why must it be replaced?
Oh right the other chain is a balancer chain! Thanks, briefly does it balance the timing chain or something?

I did see a forum member selling these kits who is he and where do i find him?

Oh and is there some sort of guide to replacing timing and balancer chains?

Thanks very much, Simon.

On a 4 cylinder engine out of balance forces are present due to the rotational mechanical forces on the crankshaft inherent in combustion timing of the firing cycle on a four cylinder engine i.e. firing every 90 degrees of crankshaft rotion, the purpose of the balance shafts are to even out these peak forces and dampen out of balance mass. 6 cyinder engines have inherent in their design a smoother output (rotational torque) on the crankshaft due to the increased firing cycle i.e. firing every 60 degrees of crankshaft rotation and have an improved balance effect without the need for balance shafts. 8)

I would think that a sagging balance chain would only have a minimal effect on the damping process.

Is there any history of balance chains breaking? notsure.gif

sigibbons

Ok well looks like i'm going to stump up and get both chain kits.
Where is the best place to buy and what price should i be paying?

Also is there some kind of step by step guide on the net anywhere, that would be usefull.

Thanks, Si.

vocky

autovaux are probably the cheapest or sometimes they are on ebay, search for z22se