G60 lost 2 cylinders, aarrgghh!! help?

[Henny 0]

Well, with the beautiful weather we've had this weekend, what better thing could I do then spend a day in the grease, oil and shadow of my car?!? :lol: :cuckoo:

 

Head's off now... and I'm still buggered if I can work out what's wrong with it... :brickwall:

 

The head gasket looked fine, no obvious damage I could see, although it does look a little more seperated between the layers where it seals between 1&2 cylinders, although that could simply be where it's come apart taking the head off... Good news was that all head bolts were equally tight, and the threads all look good on them, so the heli-coil has held nicely, so the block's not scrap....

 

The pistons and bores all look good, so it's not a cracked block, and the valves, although somewhat blackened, all look OK too, so I'm a bit stumped.... time to send the head to someone who knows what they're doing I think... :?

[dirtytorque 0]

change the dizzy maybe??

Maybe the hall sender isn't sending a proper tach signal??????

 

Worth a shot.:shrug:

[Henny 0]

but it was giving a nice clean bright spark on all 4 cylinders at the correct time... I don't think it's ignition based, I think it's a mechanical failure/problem somewhere in the head...

[dirtytorque 0]

but it was giving a nice clean bright spark on all 4 cylinders at the correct time... I don't think it's ignition based, I think it's a mechanical failure/problem somewhere in the head...

 

 

True true...

 

strange one,thats for sure.

[Henny 0]

well, I've sent the dizzy off to a member of Dubforce who is trying it in their G60 for me... and it seems to be working in there engine so far with no problems.... :brickwall:

 

'tain't that then.... :(

 

Time to strip the head down and see if I can find anything wrong with it then.... :shrug:

[CTWG60 0]

well, I've sent the dizzy off to a member of Dubforce who is trying it in their G60 for me... and it seems to be working in there engine so far with no problems.... :brickwall:

 

'tain't that then.... :(

 

Time to strip the head down and see if I can find anything wrong with it then.... :shrug:

 

I'd get it pressure tested first, impluse do a good job see my sig for a link only about £20 iirc. I don't think they are far from you. They can check the face for warping aswell etc.

[Henny 0]

I'd get it pressure tested first, impluse do a good job see my sig for a link only about £20 iirc. I don't think they are far from you. They can check the face for warping aswell etc.

 

Gotta strip it down to get it pressure tested... it's still got both manifolds on it, phenoloic (sp?!?) gasket, oil feed to the charger, the cam etc... attached! I may be able to see something once I get these off, but if not, then it'll be sent off to be checked for flatness and pressure tested... Thanks for the recommendation though, I'll give 'em a bell and see what they say... 8)

[dragon green 4]

Did you dissect the headgasket ?

I know you said it may have come apart as you dismantled it, but are you sure there wasnt any carbon deposits between the layers of the gasket,

when the engine is cold it fires on all four, but soon as it warms up(4or 5 secs) only onto two cylinders,

I agree with you, its mechanical, not electrical.

My money is on the headgasket !

keep us posted

[dirtytorque 0]

That's the whole electrical system eliminated then.I was thinking maybe hall sender but thats been ruled out now.

 

 

don't envy u at all.

 

Good luck. :salute:

[Henny 0]

yup, just got confirmation that the guy has run the car for a couple of hours with my dizzy and it's been fine... right upto redline and at idle... that's everything electrical ruled out, so time to strip the head and get it tested... :shrug:

[CTWG60 0]

yup, just got confirmation that the guy has run the car for a couple of hours with my dizzy and it's been fine... right upto redline and at idle... that's everything electrical ruled out, so time to strip the head and get it tested... :shrug:

 

Just out of interest what will you go for next if it passes? :roll:

[Henny 0]

yup, just got confirmation that the guy has run the car for a couple of hours with my dizzy and it's been fine... right upto redline and at idle... that's everything electrical ruled out, so time to strip the head and get it tested... :shrug:

 

Just out of interest what will you go for next if it passes? :roll:

 

PG block with new standard pistons, standard crank, my spare standard head and the standard ECU chip I have kicking about + a for sale advert... ;) :lol:

 

Seriously though, at that point, if I've not found anything wrong with the bottom end when I rotate the pistons, I think it's probably gonna be a thicker single piece metal headgasket to drop the CR slightly and eliminate any chance of it blowing through the layers of a standard G60 head gasket... :? Then stick it all back together again to see if it runs or not... If not, then it's rethink time, if it does, then it's sorted... :)

[CTWG60 0]

yup, just got confirmation that the guy has run the car for a couple of hours with my dizzy and it's been fine... right upto redline and at idle... that's everything electrical ruled out, so time to strip the head and get it tested... :shrug:

 

Just out of interest what will you go for next if it passes? :roll:

 

PG block with new standard pistons, standard crank, my spare standard head and the standard ECU chip I have kicking about + a for sale advert... ;) :lol:

 

Seriously though, at that point, if I've not found anything wrong with the bottom end when I rotate the pistons, I think it's probably gonna be a thicker single piece metal headgasket to drop the CR slightly and eliminate any chance of it blowing through the layers of a standard G60 head gasket... :?

 

Well at least you have plan. Don't buy any long pieces of rope though! :D

[Henny 0]

hey, if I can't find what's wrong, then I'll hang the engine, not me! 20VT time at that point... ;) :lol: There's enough money in that engine in parts to pretty much pay for a 20VT engine these days, and I can do the swap myself... ;)

[16v_Yellow_Corrado 0]

have you tryed coil pack i know you said it runs fine for 5 secs but i had the same problem with my car with the plugs out of the car it was firing nicley on all for plugs but when they were underload in the bores they wouldent spark tok me ages to work it out. then a slaped a new coil pack on and brooom went like a dream ever sinse

[Henny 0]

if it was the coil, it wouldn't just be doing it on only 1 and 2 as the coil supplies all 4 plugs in the same way... nice thought though... 8)

[Henny 0]

Right, well my mate who's a mechanic has now confirmed that there was nothing wrong with the head gasket... so that theory is out... Hopefully get some time this weekend to strip the manifolds off the head and see if there's anything obvious there, and then take the cam and followers out to see if there's anything there too... :shrug:

[steveo29 0]

well, I've sent the dizzy off to a member of Dubforce who is trying it in their G60 for me... and it seems to be working in there engine so far with no problems.... :brickwall:

 

 

im on here as well chief :nuts:

[Henny 0]

well, I've sent the dizzy off to a member of Dubforce who is trying it in their G60 for me... and it seems to be working in there engine so far with no problems.... :brickwall:

 

 

im on here as well chief :nuts:

 

Sorry mate, didn't realise! :oops: :notworthy: :notworthy: :notworthy:

[steveo29 0]

just a random thought..

 

could the fact your car is so tuned, could it be almost blowing the spark out due to the extra flow? prob a silly idea but thought id mention it

 

:camp:

[Henny 0]

just a random thought..

 

could the fact your car is so tuned, could it be almost blowing the spark out due to the extra flow? prob a silly idea but thought id mention it

 

:camp:

 

would do it on all 4 cylinders then though... ;) also wouldn't have suddenly done it while driving, rather would never had run properly in the first place... :(

[Henny 0]

right, well, after the car has been off the road for just over 3 years and I finally got sick of it all and started to sell parts of it off, the guy who bought the complete top end of the engine from me has found the cause of this problem... :?

 

 

Broken and weakened valve springs.... :eek: :brickwall:

 

What I didn't know when I was checking out the head while it was off was that the G60 uses 2 springs per valve.... :shrug: an assister spring and the main spring... in the case of my engine, the main spring on cylinder 2 had snapped into 2 pieces... this meant that while cranking over on the starter, the valve was closing OK, hence giving good compression readings.... However, when the engine is running, the boost provided from the charger was enough to overpower the assister spring and stop the inlet valve from closing completely causing the mis-fire... this was also allowing contamination of the boost feeding into cylinder 1, hence the misfire on cylinder 1 too... :brickwall: :brickwall: :brickwall:

 

so, all in all an :epicfail: from me in not finding this problem and rectifying it 3 years ago... :roll:

 

Hey ho, one to chalk up to experience there then... On a positive note, what it does mean however, is that there's nothing wrong with the bottom end of my engine...

 

Time to get saving for another CNC head, red-tops and Newman cam shaft then I think to get my little baby back on the road... :cuckoo: :lol: :help:

[dirtytorque 0]

bitter sweet news.

At least you know what it is now..

You don't want to maybe run it on a standard head for a while?

How much stuff have you sold off it?

[pete_griff 0]

hey Henny, glad to hear the mystery has finally been solved.

 

when you had all the cnc head work done originally didn't you get new valves/springs/guides at the same time?

 

that said that's pretty shocking news about the springs - i've never heard of that happening, even with running high-lift cams.

sounds quite odd...

 

wasn't there ever a rattling if one of the springs was broken?

[Supercharged 2]

That's good to know mate but makes me worry even more about the quality of my CNC head and didn't yours come with the valves / springs in place ?

 

I think mine is just a standard GTI one and doesn't have the sodium exhaust valves - runs hotter that ever but doesn't loose any water and everything else seems to be working fine.... I wouldn't buy another to be honest though, too much money and the corrosion on the outside of mine was unacceptable - man in the shed next time for me...

 

Also were you running a cam? I know Shrick say you should uprate the valve springs with a high lift cam but most people don't....