306oc - Peugeot 306 Owners Club & Forum

Ok so as few of you have tried to help with this via messages and chatbox thought I'd show you exactly what the issue was...























Probably my favourite cylinder this one...










Now as funny as that is, I really can't understand why it's happened! The cambelt is still intact and the cams line up, not checked crank but I can't see that slipping? And why have only some valves been damaged, both valves open together, yet one of each pair seems to be worse off. The car has sat for a while, but the engine turned over by hand ok before starting (starter solenoid broke while sitting unused).

So anyone know why it's happened? Or anything I can do/see to confirm why it's happened?

Cheers
Tom

Mate i think that needs a new head gasket. Theres some coolant in them cylinders....

No idea why its happened. All i can say to you in my professional opinion its f*cked!

(03-11-2015, 05:31 PM)bashbarnard Wrote: [ -> ]No idea why its happened. All i can say to you in my professional opinion its f*cked!

Even my unprofessional self could've guessed that lol. I need closure though, need to know why its happened or it'll keep going round my mind lol.

Belt slipped.

No similar pics or tales of woe on the rover or MG forums?

you f*cked that one tom! i recon the warrantey has expired

Wow

Any chance the bottom key way sheared off seen this happen to a vw crafter before but not as bad as yours lol that's sum mess :-)

yeah bottom key way or a section of the cambelt teeth have stripped.

Cambelt is perfect all the way round, it's been turning over fine on the starter with no compression until Sunday when it finally locked solid, presumably that was the inlet valve getting stuck in the head.

I really should check the bottom pulley though, requires jack and probably something to remove the alloy that will be seized on after not being removed for years lol. It still turned backwards this morning before I pulled the head though, so keyway can't have failed either. It's possible the belt may have slipped around the crank pulley I guess.

Let us know when you find something would really like to no :-)

Yeah I will, I really want to know as well lol! It's not like it's a rough old car either, it's only covered 61k and he's owned it from new with regular services. Whatever has happened is almost certainly caused by being sat unused for over 2 years, and not even started in the last year. Cars really can't be left standing, if it was mine I'd have sold it back when it still had some value, but I know some people get attached to cars lol.

looks to have been a tapper for some time then finally dropped a valve or two, bending the rest when the heads come off and stop the crank turning.

Its not a '6 lol. Ran fine last time it was running so I'm told.

That devastation can only have happened at ~250rpm on the starter motor amazingly! That's why I'm so shocked about the smashed piston, I can understand valves bending or even snapping at low rpm but you must need some serious force to smash a piston like that.

(03-11-2015, 08:11 PM)Toms306 Wrote: [ -> ]Yeah I will, I really want to know as well lol!  It's not like it's a rough old car either, it's only covered 61k and he's owned it from new with regular services.  Whatever has happened is almost certainly caused by being sat unused for over 2 years, and not even started in the last year.  Cars really can't be left standing, if it was mine I'd have sold it back when it still had some value, but I know some people get attached to cars lol.

Ye ur right about it not being good for them to lying up I rebuild a lot of engines in the van breakers that I work in had a (01) 2.8hdi Peugeot boxer camper come  In only 12k on the clock and it dropped a valve  but luckily we got her up and running again :-)

I think this is a bit beyond getting running again now lol. Cheapest way would be a replacement engine but that's worth more than the car. Will most likely be stripped and scrapped. I'm determined to prove the cause of the failure first though.

(03-11-2015, 08:40 PM)Toms306 Wrote: [ -> ]I think this is a bit beyond getting running again now lol.  Cheapest way would be a replacement engine but that's worth more than the car.  Will most likely be stripped and scrapped.  I'm determined to prove the cause of the failure first though.

Lol I know that engine done no going back now lol

doesn't have to be a 6 to be a tapper.

True I guess, it's never had a belt change though so shouldn't be any reason to be a tapper?

How old is it? Can you guarantee it's never been over-revved? Never been run low on oil? Never over-heated in traffic? Is the owner more attuned to his vehicle than 99% of owner drivers who will ignore anything that doesn't bring the engine light on? Reckon you've probably got the point.

It looks like it's been smashing the valves on the starter without the operator noticing, so i guess there were some stuck valves from being sat for so long. But then maybe the water pump was seized and the belt jumped a tooth or two when it was first turned over. Tbh you can't know without taking it apart to find out.

Ah the old K series never fails to disappoint

Would probably say stuck valves? Only looks like pistons 1 & 2 are seriously damaged where if it was cam timing out wouldnt it be like 1 & 3?

You do have quite a bit of leeway with these,mine was running 90 degrees out of timing at the crank and only 1 inlet valve kissed the piston slightly

(04-11-2015, 06:42 AM)Poodle Wrote: [ -> ]How old is it? Can you guarantee it's never been over-revved? Never been run low on oil? Never over-heated in traffic? Is the owner more attuned to his vehicle than 99% of owner drivers who will ignore anything that doesn't bring the engine light on? Reckon you've probably got the point.

It looks like it's been smashing the valves on the starter without the operator noticing, so i guess there were some stuck valves from being sat for so long. But then maybe the water pump was seized and the belt jumped a tooth or two when it was first turned over. Tbh you can't know without taking it apart to find out.

It's 11 years old, 61k - and it was driven hard lol, what's the point of Halfords looks if you don't drive it like a 17 year old?

I was the first one to turn it over on the starter. My neighbour was stood there watching as well though and neither of us heard anything except the lack of compression - he's a bit of a car guy and has done HG's on his Rover 25 hence his interest in getting this running.

How do valves get stuck through lack of use? Collapsed lifters or something else? Some of the lifters weren't following the cams when I pulled the rocker cover after finding the lack of compression but that may've been after the valves had already bent so wouldn't seat properly.

Nice looking combustion chamber, apart from the damage that is....

Car sat for 2 years ? maybe a clue there.......

You live close to the coast, or in a wet/humid area ?

Valves can and do ( I have seen it myself on older vehicles, engines etc ) stick open, with catastrophic results, as we have seen.

Some valves will be open when the engine is a rest, so any dampness  will get in the cylinder eventually, not to mention any gum etc on the valve stems.

The engine turned over by hand ( rather than just jump starting and whizzing the engine over on the electric starter ) , which is always a good practice on engines that have been standing for a while, but inclined valves are a bit different, as they are "inclined" to get bent ( if stuck open ) by the up coming piston.

Turning the engine over slowly by hand,  its as well to watch all the valves open and close, feel for any "clunk" or tight spot ( valve touching piston ) and watch for "enlarging  valve clearance gaps", suggesting a stuck open valve,  with the plugs out and some oil down the bores. Some oil or lub on the rockers/buckets etc and on the valve springs and upper stems is also a good precaution.  Over the top, no, not really, just see the pictures.

Not too difficult on a 4 cylinder but much more complex on a v12 believe you  me.

In the old days when most valves ( not all by any means ) where inline with the pistons, a stuck open valve would be "snapped shut" by the up coming piston, a gentle nudge ( when turned over by hand ) to free the stuck valve off. You would hear the "whack/crack" of the valve slamming shut.

A tv comedy show with a "master mechanic" ( my god he don't half break a lot of stuff ! ) says that the engine should be turned over by hand ONE REVOLUTION, yeh that's why he's a master, right ?

Watch the blue FIAT/SEAT episode, the car not sounding too healthy as its trying to start, sounds like a low compression, starts sort of, backfiring thru the carb until it suddenly clears, stuck valve maybe ??

So, be warned, if the car has been sat for some time, think stuck valves, take your time and be very careful.

Yeah it is right on the coast, on damp grass, under a tree with no sun penetration... So dampness is an issue lol.

What else should I have done to check for stuck valves then? Thought turning it by hand should've shown any problems and as the lifters wouldn't be full without oil pressure pulling the cam cover isn't going to show much?

That's all reasons it could be a tapper, i meant. Probably knackered before you got to it, it is a k-series after all. A magnet for hard drivers, as you say lol, combined with being sat for a couple of years on the coast, just to make sure.

Can't really do much more than pug306driver says tbh, not without going as far as pulling the cams to see if all the valves return.

If a valve was stuck open, the "bucket" would not have risen due to the spring not pushing the valve closed and bucket up.

Even a closed valve when engine stationery, can "stick" open when forced open by the cam, but again bucket would not have risen for the above reason, spring not closing the valve etc..

---

looking at the pictures again, all the inlets have hit the pistons ( other way round more like ) but no tell tale marks on the exhausts, maybe they clear or miss the piston crowns.

The belt was perfectly ok ??

any other history with this car like, its just had a new cam belt and then this happened ( not timed correctly, or belt not tensioned correctly ? ) ??

academic now cos the damage is done, by still nice to know why. history repeating its self is not good.

One of the exhaust valves must have hit the piston, that's an exhaust sat on the left hand end piston in pieces lol, but the others don't seem to have done as you say, unless they're stronger valves on the exhaust side maybe? Or maybe that one was taken out by the inlet valve head flying around?

But what's really odd is that the valves on each cylinder open together, yet one of each has taken far more punishment than the other, yet they'd either both be closed or both open when the engine was stationary or if the belt had slipped, strange! Belt was perfectly ok yeah, though I never checked crank timing before pulling the belt so we'll never know if that was out now, but that's looking unlikely. Car was owned from new by my step-Dad, never had a cambelt change and I admit this one was a bit crunchy, but all teeth were fine and it was still tight, I've seen far worse belts lol.


We will most likely be pulling a few parts off it now (including the ~£200 worth of parts that were replaced over the last month!) and it will be sold on as a rolling shell for use in racing - if anyone is interested in any parts or the rolling shell let me know.

the inlet valve remains well and truely punched into the cyl head, quite deep, probably took that exh valve out/////good pic of that exh valve "failure"....

whats the valve timing on this engine, inlets opens at ??????........etc

(07-11-2015, 11:16 AM)pug306driver Wrote: [ -> ]whats the valve timing on this engine, inlets opens at ??????........etc

Inlets seem to open shortly before TDC looking at the pics. But seriously I have no idea.