Cheers pal! Its in a spot of trouble at the minute. On the way back from santapod it started tapping rather loudly and now its smoking like a house on fire. Problem is I'm booked in at uni doing my dissertation (in a wind tunnel) so I dont have much time to play with. Needs sorting as I want a remap with PPP!

Right after getting the turbo conversion up and running managed about 200 miles before problems started. Half way back from Gti fest a loud tapping noise came from the engine bay. Checked the oil, absolutely dry. Filled her up at Leciester Forest East till she was at the top of the dipstick. Engine still tapped untill I got home. Checked the oil again and it was pretty much on the bottom of the dipstick so filled her up again.

Smoke then started to pour out , checked the oil now it said it was overfilled. Drained the oil fully and chucked in 3 lt so it was about 1/4 up the dipstick.

Engine is now tapping loudly and smoking like a house on fire.

From my mates I've spoke to and myself we think its either a fried ring or a melted piston, although its running on 4 cylinders

Thing is my AFR was reading 10 whenever on 0.2-0.4 boost as my 6psi switch actually needed getting up there. Engine temps were always cool too.

Then checked the timing, slipped 1 tooth ACW .

Heres the result ...

Video of the hideous noise :(

Heres the plugs

Looks like plug ones been melted

I'm going to compression test it tomorrow hopefully

The gap on those plugs looks seems quite large......

Right today I've done some snooping around

Number 1 cylinder

234 looked good on the bore scope.

Then proceeded with a dry compression check

6 9 8 10

I will do the wet check tomorrow. Looks like cylinder 1 has melted

the suspected diagnosis...

head off, cylinders 2,3,4 looks like overfuelling massively.

cylinder 1 closer look

hello melty

Been speaking to PeteG40 and he reckons i'd probably get away with a hone new piston and rings. Although I reckon i'd like to get some forged items.

yeah i would go for forged mate if you can afford them at least just for piece of mind and rods and pistons ideally

Just pistons I reckon mate, Yoof seems to have found the limit for the rods and I'm not getting anywhere near that sort of power with mine. Wossners seem to be the choice one after reading around abit. Most people went accralite then wished they had got wossners.

Noo! bad news

If the cylinders are over fueling, why do you think the tempretures have been high enough to melt the piston in that cylinder?

Or would it be ignition related?

If you ever need a hand with this give me a holla, i'm not far away. Also, in a few weeks the space in my lock-up will be free for a bit, so you could lob it in there if you really needed to.

Cheers max thats a kind offer. Ill let you know how I get on if I need a hand.

Actually just sorted some wossner pistons out off Phil J ( I must be his favourite customer) and I'm guna get my mate who you met at the pub to ring round vw for the parts at trade price. Hopefully should be around 8-9 hundred for the fix

Gees.

Any idea why it melted though if the problem wasn't lean running?

At the min I'm abit puzzled, Phil lead me to this post of club g;

Anyway, thought this should be useful. A definitive checklist on how to avoid melting your engine for anyone who has built, restored, recently bought or just had a G40 laid up for a while.

First one which has prompted me to write this, Mark’s G40 started misfiring recently, easy fix – unplug the lambda and sorted. The lambda was new a year previously so something has killed it, running too rich or lean. The car had an issue where the fuel pumps wouldn’t prime, turned out the connector for the relay had corroded just enough to stop the contact. Had that not been driven like a vagina, rather than the lambda probably would have taken the engine out. Worth a look for any 40’s that have been laid up.

Another one sometimes forgotten is the wiring in the top of the fuel rail, again corrodes, goes brittle etc.

Fitting a smaller pulley/upping the boost without the fuel to suit a quick way to achieving an extra oil pump. IE a chip for a 68mm pulley and fitting 65mm toothed belts will do it on about the 3rd 145mph run.

Injectors, fuel pumps, shit in the tank and blocked filters will all lead to the same. Easily done with how the tanks corrode. Can you still get the accumulators (yellowish box by fuel pump) from vw? Haven’t asked in a while…

Timing’s always worth a check, both of.

Realistically a G40 shouldn’t melt if its right and it’s always a shame to see them go down.

Sure everyone else can add their bit, might save a few engines.

My injectors were apparently cleaned not long before I got them and the pump always seem'd to work fine before the conversion. The timing did skip afew teeth but I dont think its down to that. I filled the tank up to the brim for the trip down to pod so I think shit in the tank has come up and blocked it somewhere.

I reckon I'm guna get a new tank,filter and clean the injectors before shes running again. Maybe even get some metal fuel lines.

Right an update on this finally! Took the head off to get some work done where PeteG40 mentioned (skim, new valve guides, stem seals, 3 angle valve and seat cut and a pressure test) then also took the injectors to be flow tested and cleaned.

Head is getting done today but got the results back from the injectors.

Turns out all of the injectors had good spray pattern, 4 of them had flow of 260cc and one of them had a flow rate of 240cc . The guy reckons  i should chuck the "knackered" one and find a new one. They also do turbo rebuilds for 200 so i may also end up going up again!

So i'm looking for a G60 injector now!

Also got the main and big end bearings on order from Rotherham Engine servies, picking up all bottom end seals off Pete next week. Just got to wait on the pistons now from Phil J!

I see you're after a GK inlet. How come if you don't mind me asking?

GK inlet?

Nice work dude,

Where did you take the head to have the head done?

The place i take mine too for new guides don't do 3 angle valve seats

GK inlet?

Sorry. Being a mong. Was a lad named edgies

http://www.cylex-uk.co.uk/company/rotherha...d-16402599.html

Rotherham Engine Services mate £130 for all the above!

Edited 15 December, 201213 yr by etches69

looks good chap. shame about the melty piston.

Bit of an update now;

Bottom end totally ripped apart and to the engine shop for a full clean and for a 2mm overbore for the wossner pistons

The heads come back RES where its had

head skim, 8 valve guides, stem seals, cam oil seal, three angle valve cut 3 angle seat cut

I've got to get some 315cc injectors which is next on the list

Got these in the post today - Cheers Phil!

Means they can be given to RES for the bores to be matched!

Unfortunate dude, but be coming back bigger and better eh, and your mind will be at ease having a fresh stronger engine :)

I've got some white doors in pretty good shape if you're after some. What plugs were those melted ones they don't look like G40 ones?

Just look like some sort of NGK ones dude, came with the car when I bought it. Seemed to run well enough though. I will have them doors off you depending on the price of course. Will be in a couple of weeks as I've got 4 final year exams coming up!

Great read dude but at the same time has put me off buying a g40 lol heartbreakers!!

I'd recommend you get some Bosch W5DP0 plugs if you haven't already. I don't know much about NGK plugs but if they weren't the right temperature that could explain why they melted!

No rush on the doors, I'm hibernating at the mo