Think it's going to be best to take the head off and inspect it while I'm at it. Be a shame for two month down the line cylinder 3 gets worse and starts miss firings.

Contrary to what Toxic said, i dont know why these engines burn up exhaust valves, probably as Wino said, poor valve guides/valve seats at the manufacturing state.

 

I have heard of people not topping up the oil, which has resulted in chains stretching/premature wear on the valve train, I am under the impression that the 1.2 12v's do have oil pressure controlled chain tensioners. So it only takes someone to mistreat the engine and they seem to go pop!

 

 

Regarding Compression, with the Oil at atleast 30 degrees Celsius

 

at new:          15 Bar

wear Limit :   11 Bar

Max diff :         3 Bar 

 

if you are reseating the valves, both intake/exhaust valves have a 45 degree valve seat.

 

hope this helps

So cylinder 3 is past the wear limit regardless then!

Is there a way to just remove the "rocker cover" and line up the timing to check it runs or is that not possible on these? Ie a full strip down is needed.

As for the valves, I was going to replace the exhaust valves and just clean up the inlet valves if they are ok, will be grinding them in by hand (well a tool you put in a drill) and the paste so the angle shouldn't be a problem would it?

Thanks.

Edited 30 January, 201511 yr by hutchysrs50

but as i said, with oil temp at atleast 30 degC. if you did it in the blistering cold, it would be less, no?

I guess, it was snowing and frozen outside. The car hasn't been started / turned over in about a month.

I'm just worried about cylinder 3 being lower than the other two to start with.

I reckon it would be worth trying to get it indoors, and a bit warmer, charge the battery fully, then repeat the compression testing.  It might be wishful thinking, but could it be that you did the logical sequence cylinder 1 first, then 2, then 3, and the battery was tiring by the time you tested No.3? I'm not sure that speed of cranking should really affect the compression reading much, but it must do to some extent.

No, warming it up won't help, cylinder 3 isn't very clever but it should run nonetheless if you correct the timing issue.

For my own piece of mind, I think I'm going to take the head off, at least I don't have to worry about it at a later date. For the price of some valves and a head gasket set its worth doing when the timing chains off, since it's abit of a chew just changing the chain.

For my own piece of mind, I think I'm going to take the head off, at least I don't have to worry about it at a later date. For the price of some valves and a head gasket set its worth doing when the timing chains off, since it's abit of a chew just changing the chain.

 

Agreed, you'll need new headbolts as well.

If the valves are gone (judging by the reading you have from the compression test it is likely gone) Then replace all of them with the guides. Car will start with the iffy valve but run on one less cylinder, which is super fun when you're 80 miles away from home and haven't a clue when you are. Hope you get it running!

I've never changed a valve guide, so don't think I'll be replacing them. I will however check for play in the valve and if it does need replacing get an engineer that does them for me usually.

It's just an extra cost for a cheap run around, don't want to go over £150 - £200 ideally.

I had all three valves and guides replaced with a new head gasket + all stuff needed for that for £250 (I didn't pay it, my dealer had too as car was sold to me broken) Can't complain! 

When the car does fire up, it'll shut down the cylinder pretty quickly, mine was when it idled hot so i got a misfire code.

Got round to pricing up parts today.

Timing chain kit - £115

Chain, guides, tensioner, sprockets, proper sealant, crank seal and bolts.

Head gasket set - £46

Head gasket, valve stem oil seals, head bolts, exhaust gasket and 5 o rings for coolant and inlet.

Exhaust valves (6) - £40

So a tad over £200 for everything needed to do the full job.

Will have to check valve guides but really hope they are ok or will at least be better with new valves in. Will also give the cylinder head a very light lick over so it's totally clean and flush.

Good luck with it. 

Does Haynes (or Autodata, or wherever) have a figure for maximum acceptable valve-in-guide front-to-back waggle?  Can't remember whether I've seen reference to checking them.  

I've got a manual so will check, if it's bad then it will have to be done, but slight play I can live with. Hopefully the new valve will be slightly thicker and take up a tiny bit of the play. At the end of the day if it runs fine now, then it will run fine with some new valves and the others taken out, cleaned and ground in some extra also.

I suspect you'll find that the wear on the valve stems themselves is virtually unmeasurable.

:(

Like I say, it's somthing I've never done before.

Quite low mileage at 82,000 though, should have life in it still.

Also, any advice on removing the side cover?

All the vauxhalls I've done in the past have handy raised lips at the side so it prises off no problem, I've done two fabias now but a few year ago and can't really remember how I got it off.

Hopefully the new valve will be slightly thicker and take up a tiny bit of the play.

 

Not a chance, the guides wear, not the valve stems.

Not a chance, the guides wear, not the valve stems.

Thanks, I wasn't sure. I hoped it might have been 50/50 wear. I'll find out next week hopefully.

Wear limit is 0.55mm for exhaust and 0.50mm for inlet.

As for advice for removing the side cover it says..

"Removethetiminggearcover.Useslightknockswith a rubber-headed hammer from outside to loosen the cover as necessary (the timing gear cover sits on the fitting sleeves)"

Although it still seems pretty solid!

Well done finding the wear limits, I didn't find that in Haynes yesterday.

What it does suggest when taking the chain cover off is taking the sump right off first, which then gives you a bottom edge (of the chain cover) to grab and pull, I guess. Never done it though, so maybe no help?

Wear limit is 0.55mm for exhaust and 0.50mm for inlet.

As for advice for removing the side cover it says..

"Removethetiminggearcover.Useslightknockswith a rubber-headed hammer from outside to loosen the cover as necessary (the timing gear cover sits on the fitting sleeves)"

Although it still seems pretty solid!

 

Nylon hammer, give it some.

 

20 thou on the guides means the valves will rattle from side to side with no springs fitted.

Edited 21 February, 201511 yr by sepulchrave

There's a pic in Haynes showing where the loacting dowels are; near the bottom of the rear edge, and just below halfway up the front edge.

So avoid trying to knock those areas, it won't help.

Thanks, might get to try next week depending on the weather.

The sump is still on currently, removed half the bolts from it though, it will need to stay in place until the day the job gets done so the bonnet can still get closed. When I fit the engine support the Bonnet will be left open until the jobs pretty much finished.