Went Eurocarparts to get a new ABS sensor for the Golf Anni and decided to take the G as it was nice and cold so the old charger would love it.
Blasted down the dual carrageway (me and yoof's test road) full pelt and the engine spluttered at 6000rpm suddenly.
Pulled over and the car was running REALLY REALLY rough. Waited for the AA man as i had no tools and removed Cylinder 1 plug and here it is!!!
(http://i19.photobucket.com/albums/b155/robinyau/plug.jpg)
Its a proper Bosch W5DP0 as well, only done like 200miles!
Replaced the plug and it still running uber rough so the head is coming off as i reckon the valve will be bent if the end of the plug has gone through it!
The head was coming off anyway for the 1341 high lift cam but i wasn't expecting to replace the valve or the head if its proper fucked!
COCK!!!!!
bloody hell! Dunno how you've managed to do that.
No idea paul, i guess it just can't put up with rockets heavy right foot!
You not selling your old cylinder head are you paul...............................might need one if mine is shagged.
hmm well I've got the head off my g40 but the waterways are a bit corroded. It never leaked but it's less than ideal. To be honest mate you'd be as well just getting a cheapo 1.3 CL head and swapping the cam and exhaust valves into that and refreshing it a bit. I'd get your head off first before you start worrying too much about finding a new one.
not a rogue shitty plug then?
Right the head is off! busy couple of hours thats for sure!
Exhaust Valve on Cylinder one is mullered, the seat is shagged as well.
It looks like the plug tip got mashed in between the valve and the seat.
I am guessing seats aren't replaceable and if they were i think it might be best to get a replacement head as the valve guide might have been damaged as well.
Ah well at least the pistons look good and there is no signs of det which is even better!
On the plus side i was going to have to take the head off anyway to fit a new cam and also new cambelt etc and to inspect the pistons. Just need a new head now!
Oh piccies
(http://i19.photobucket.com/albums/b155/robinyau/exh1-1.jpg)
(http://i19.photobucket.com/albums/b155/robinyau/exh2-1.jpg)
(http://i19.photobucket.com/albums/b155/robinyau/exh3-1.jpg)
(http://i19.photobucket.com/albums/b155/robinyau/exh4.jpg)
(http://i19.photobucket.com/albums/b155/robinyau/exh5.jpg)
(http://i19.photobucket.com/albums/b155/robinyau/exh6.jpg)
Ouch :(
Maybe an excuse to convert it to a Big Valve Head ;D
lol Yoof is currently on the phone to me trying to convince me to do the big valve head route as well!
its expensive but i'll try and talk tracey into funding some of the monies for it..................
bloody hell! yeah that's going to be a new head required. Just get any old 1.3 CL head, if you need a proper g40 exhaust valve I have a set of four I'm not using.
That head may not be scrap if you get bigger exhaust valves, which will have new valve seats fitted. Best to take that head and get it looked over by a cylinder head specialist. They can do all sorts of repairs!
i'll be going back to a standard head as i can't find the funds for a BVH as i still need a new exhuast system, spent this weekend patching up the back box with chemical metal!!!!
Get yourself the set of exhaust valves from Mr Hayes and a 1.3 CL head from the scrappers and your onto a cheap enough fix, as long as you want to do all the labour 8)
nasty pics not nice at all
that spark plug i could not belive my eyes when i saw it looks FUCKED
and your head not looking good aswell
things always go wrong when you dont have money i hate that ow well best of luck fixing it mate
hope its on the road soon
It's a shame there isn't any kind of warranty etc involved with this kind of thing, although you were going to do it anyway you shouldn't have been forced to do it because of faulty brand new parts.
If this had happened to me i'd be shagged, i've got enough knowledge to do bits n bats with the car, i wouldn't be able to strip down a head though...this would cost a lot of scrilla £££!
good luck with it!
The engine is in bits now, i have just removed the water pump and realised that the previous owner had put the wrong pump on so the teeth don't match the teeth on the belt!!!!!!!!!
I'll be changing the cambelt and water pump now seeing as the engine is in so many bits!
Got a head sorted out for it as well which is good news, thanks Mr Hayes!
Whilst i am at it i'll put a new clutch in as well but its going to be a mission as the subframe was a right git to put on so i am hoping i can make enough room in the engine bay not to have to drop the box out the bottom of the car. What do you guys reckon? Do-able?
(http://i19.photobucket.com/albums/b155/robinyau/engine.jpg)
i doubt you will get the clutch in without taking the box out as there is very little room. worth a try but i very much doubt it...wtf about the water pump though?! thats seriously not good! obviously been given the wrong year waterpump of the two available and just made do or not even noticed! that alone is worth noticing whilst in bits.
before anything id be getting them injectors tested mate!
injectors have been tested then cleaned and then tested again, all matched pretty much spot on.
looks like its ran lean mate, fuel pumps good?
no problems with the fuel pumps as i run a wide band AFR meter in the car and that was reading 0.78 lambda.
I'll check the fuel rail before i out it back on.
Pretty bad the spark plug melting like that. Were they genuine VW W5DPO's or ones from GSF ? Would be an even more expensive problem if it had happened to a new BVH. I'm sure those of us getting them done will share a big concern of this happening again !
ones from GSF are proper Bosch ones though I'd expect them to be good quality. I'd put it down to a freak manufacturing defect or that cylinder running lean for some reason.
well cylinder one gets most heat from the least efficient exhaust port - so maybe it overheated that cylinder - what with the shit water pump
The plugs bosch make for VW may be to a slightly better standard than std aftermarket ones with their name on. As they are roughly the same price I know where I will be getting a set from.
Pete, why has No. 1 got the least efficienct exhaust port ?
cos its most restrictive due to the bend round the charger
because the charger is in the way so the pipe has to bend around it and also the charger restricts cool airflow to the cylinder head as well
The exhaust ports are all the same efficiency wise.
The No.1 exhaust manifold branch does have a slightly tighter turn, however whether the efficiency losses are more than fractional I very much doubt. Even if the manifold was very poorly designed, the significance of the restriction wouldn't be enough to increase combustion temperatures to melt a plug.
There is very little in the way of cooling airflow to the engine anyway, putting the charger in front of cylinder No1. ain't gonna make much difference.
I bet if you could put a temperature probe into each of a G40's standard cast manifold primary pipes, the EGT's in all four would be very similar indeed.
This is either a plug related failure or for some reason the engine momentarily ran very lean on No1 cylinder.
hi i know this is a bit off topic but im interested to know something. i,ve seen inside quite a few g40 engines now and all of them seem to have the edge of the pistons washed clean {the edge nearest to the front of the engine} why is this? is it oil washing past the piston rings and washing the edge of the piston clean?
Quote from: breadman on January 02, 2009, 09:38:09 PM
The exhaust ports are all the same efficiency wise.
The No.1 exhaust manifold branch does have a slightly tighter turn, however whether the efficiency losses are more than fractional I very much doubt. Even if the manifold was very poorly designed, the significance of the restriction wouldn't be enough to increase combustion temperatures to melt a plug.
There is very little in the way of cooling airflow to the engine anyway, putting the charger in front of cylinder No1. ain't gonna make much difference.
I bet if you could put a temperature probe into each of a G40's standard cast manifold primary pipes, the EGT's in all four would be very similar indeed.
This is either a plug related failure or for some reason the engine momentarily ran very lean on No1 cylinder.
I partially agree, but what you say isn't strictly ture.
The exhaust ports themselves are the same efficiency wise, the exhaust manifold itself isn't. The increase in pumping energy required on Cyl. 1 to clear the tight radius will have an effect on EGT after a few cycles. I agree with you about it not being significant enough to melt the plug. The charger brackets etc do make a differance on block distortion, they're basically a heatsink for the exhaust, and as such retain alot of latent heat, don't be so quick to rule things out.
Personally I think it's a bad plug. I've not seen it yet but even with Robin's state of tune (circa 160bhp) a W5DPO should withstand the increase in EGT. Also there would be evidence on other plugs of a failure about to occur if fueling or ignition timing where indeed the case.
The injectors have been flow tested a few times and came out fine, the fuel rail can't really go wrong either, it's a plastic rail! and Cyl. 4 is furthest away from the intake anyway, so I expect this would experience the biggest pressure drop.
I no longer run Bosch plugs, and havn't for a long time as they don't like nitrous and I find when you go boyond the relms of W4 they like to missfire when cold. NGK are far better (and cheaper) one of the few things people pay attention to until they go wrong like this!
what are the codes for the plugs you are using yoof? why are they better? do the cope with the heat better ?
steven
Quote from: poloeatonm45 on January 02, 2009, 11:22:41 PM
hi i know this is a bit off topic but im interested to know something. i,ve seen inside quite a few g40 engines now and all of them seem to have the edge of the pistons washed clean {the edge nearest to the front of the engine} why is this? is it oil washing past the piston rings and washing the edge of the piston clean?
This is the thrust face of the piston.
Quote from: Dan on January 02, 2009, 07:28:26 PM
The plugs bosch make for VW may be to a slightly better standard than std aftermarket ones with their name on. As they are roughly the same price I know where I will be getting a set from.
Pete, why has No. 1 got the least efficienct exhaust port ?
cant agree with this.... bosch plugs are surely bosch plugs wether you buy them from gsf or vw..no drop in quality..thats the way i see it anyways.
Yoof. do you prefer the ngks over the w5dpo's? or just in extreme tuning cases like yours? personally i cant fault the w5dpo's but then im not running masses of power.
The plugs i used were genuine Bosch W5DP0's but i didn't get them from the UK, i ordered 12 of them from the US as they worked out to be half the price of over here (when the dollar was good rates).
My theory is that it was a crap plug.
Quote from: supercharged spaniel on January 03, 2009, 03:52:54 PM
Quote from: Dan on January 02, 2009, 07:28:26 PM
The plugs bosch make for VW may be to a slightly better standard than std aftermarket ones with their name on. As they are roughly the same price I know where I will be getting a set from.
Pete, why has No. 1 got the least efficienct exhaust port ?
cant agree with this.... bosch plugs are surely bosch plugs wether you buy them from gsf or vw..no drop in quality..thats the way i see it anyways.
Yoof. do you prefer the ngks over the w5dpo's? or just in extreme tuning cases like yours? personally i cant fault the w5dpo's but then im not running masses of power.
Of course a Bosch plug is a Bosch plug, but the part you buy from your motorfactors is not necessarily exactly the same part that Bosch will supply to the vehicle manufacturers. E.g. VW W5DP0s are VAG branded.
It's not uncommon for the OEMs to really screw down their supplies on price - so it's not necessarily true either that VW W5DP0s are better than GSF ones, it's equally plausible that the opposite is true! I don't think it's something to loose any sleep over either way.
As Yoof's already said, the Bosch plugs really don't like nitrous - and we've both found the NGKs to be equally long lasting and as hardcore as the Bosch, but at a more competitive price. In addition the newer Bosch plugs are now W
R5DP0, i.e. resistor plugs. We both found this kept popping the existing supression resistor in the rotor arm - no such issue with the non-resistor NGK.
Barring some speshness in the head, I'd agree that this was possibly a dodgy plug - especially given that it was showing either a fairly lean burn or no combustion in that cylinder before. Perhaps the plug had been dropped, damaging the electrode?
The reason I say the W5 DPO's could be better from VAG is because OEM manufactured parts, even when manufactured along side aftermarket parts, can be to slightly different manufacturing standards. OEM standards are much stricter and there is usually less room for quality issues as this would obviously give them a bad name. Not saying Bosch would make crap plugs for one second, but aftermarket parts normally tend to have a shorter life as the cars may be serviced more etc.
Anyway, getting away from the point. I'm not sure I would buy some if they were cheap and intended for the US market. Hindsight is a wonderfull thing though...
Hindsight is a good thing dan.
The plugs were bought under the impression that because they are genuine i had no reason to doubt their quality as they were new and also genuine bosch W5DP0's.
To be honest the damage to the head is only a small problem as i was intending to strip the engine for a new camshaft anyway and what happened allowed me to notice that the wrong sodding water pump was fitted.
It going to be tough getting the engine ready for the RR day in 3weeks time but hopefully with a few evenings in the garage i should hopefully have it ready, might even have to provide Yoof with some food so he will come over and lend a hand.
That will tempt him over no problem Robin, its not like Yoof dosent like his food! :P ;D
Quote from: Dan on January 03, 2009, 07:39:21 PM
The reason I say the W5 DPO's could be better from VAG is because OEM manufactured parts, even when manufactured along side aftermarket parts, can be to slightly different manufacturing standards. OEM standards are much stricter and there is usually less room for quality issues as this would obviously give them a bad name. Not saying Bosch would make crap plugs for one second, but aftermarket parts normally tend to have a shorter life as the cars may be serviced more etc.
I know you've worked for a Tier 1 in the past, so have seen that side of the fence - but some of the OEMs I've worked with are particularly ruthless with regard to price, and in some cases are willing to accept a reduction in quality for a drop in price. Was just trying to show the other side of the coin - the parts may be different, but the OEM supplied ones aren't necessarily the best.
Either way as I said, if there are any differences in the quality of the plugs, I don't think it'd be anything to loose any sleep over.
Quote from: SamG40 on January 03, 2009, 09:42:25 PM
That will tempt him over no problem Robin, its not like Yoof dosent like his food! :P ;D
Shouldn't you be playing with Frodo's ring Sam :D
My guess is abit of rough handling in transit, possibly an old batch of plugs, and Robin as an owner, all equates to a breakage.
I'll buy a bulk of the NGK plugs I use and sell them on, I've spent far too much on plugs finding what's right for me not to make a profit out of it!
what ngk's do you 2 run then?
Quote from: lance on January 04, 2009, 11:52:11 PM
what ngk's do you 2 run then?
I'll buy a bulk of the NGK plugs I use and sell them on, I've spent far too much on plugs finding what's right for me not to make a profit out of it!
Will that be NGK BP7EVX then ?
Nope ;)
;D
After speaking to a few guys at work today (other than ian - yoof) they have come up with the suggestion that it was the valve which burnt out first, there could have been some wear or damage on the valve seat which allowed gases to pass and caused a heat spot on the valve which then let go.
When i remove the valve i'll get it under the microscope at work and see what it failed from.
When this engine melted a piston was it number 1 that melted?
this engine has never melted a piston andy.
Ah, just assumed that it'd been 1341'd because of a meltage...
nah it was 1341'd because the guy who bought it off me wanted to rebuild it and thought he might as well go 1341cc....................got all the receipts for it and totals over 1k!
Right final conlusion on why this happened.
After spending some proper time looking at the head and taking the valves out it occured to me that cylinder one spark plug has been helicoiled in a previous life and it looks like the wankers who did it had drilled right through the sodding face of the head!
They basically got a massive fuck off drill and smashed it all the way through cutting into the seat for the inlet valve and also weakening the exhaust valve seat!
I think pics will do the talking! (Ignore the marks on the Cyl 1 face - head got caught on the boot catch when i chucked it in there)
(http://i19.photobucket.com/albums/b155/robinyau/valve1.jpg)
(http://i19.photobucket.com/albums/b155/robinyau/valve2.jpg)
(http://i19.photobucket.com/albums/b155/robinyau/valve3.jpg)
(http://i19.photobucket.com/albums/b155/robinyau/valve4.jpg)
(http://i19.photobucket.com/albums/b155/robinyau/valve5.jpg)
Pikey mo fo's!
Kind of explains a lot! Probably is also the reason that no.1 plug didn't look normal prior to all this happening - guess it wasn't making particularly good compression in that cylinder?
Anyway, it's great that you've found the cause - at least it can go back together now without worrying that it could happen again.
Bit of an update, had the valve looked at under a microscope and it looks like it has melted due to exhaust gaes passing past the seat and the valve, the valve seat surface is pretty minging on whats left of it.
Hopefully this will bw sorted out on my next head as i am currently in the middle of lapping them in.
Gutted but like Andy says at least its a relatively easy/simple fix.
Whilst your here robin - you got any more pics of your rad set up. You have inspired me
You can see there that the plug would have sat further away than it should be, due the thread insert. It also looks at the wrong angle too. This will have an adverse affect as the flame would have taken longer to travel and have had a more shrouded path, possibly leading to localised heat affecting the exhaust valve there.