Broken exhaust valve

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Looks like it got really Lean in that cylinder at full boost, Have the fuel injector checked!! Going extremely Lean will also melt the electrode right off the plug.
 
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Tommiee

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Yes i will have all 4 injectors tested. Will have everything tested or measured. Would make me cry if this happens again after.a short time only because i didn't check enough
 
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I think I mentioned these were known to have some issues and RS4 injectors were a good upgrade for the K04 did you look into that? The tuner would probably have seen it go go lean if you had one dying out at high RPM as wide band O2's monitor even at WOT. If it went lean there should have been a big spike in fuel numbers. That being said at those RPM's the injector pulse width would be higher making just one going lean while not impossible but improbable, it would be more likely to show up at low to mid RPM cruising when the injectors are pulsing at lower mS. I can give you the contact info for a company in England that can check these properly and install new Teflon seals, PM me if you need it.
 

Tommiee

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Thanks trav, have my connections here because i work at a pretty big car garage. It's plausible the injector is the problem, i still suspect the oil as the problem but i want to rule out everything.
 
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Originally Posted By: Tommiee
it's typical that only Cil nr. 4 had this strange buildup on the plug, the others looked perfect. makes me thing that the plug electrode was bad for a long time and it didn't fire well making it foul. it does use some oil, maybe it'll have to do something with it.. we'll see..
misfires would have triggered the CEL before.
 

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Correct Jetronic, But if could be that the spark plug was firing OK, igniting the fuel/air mixture, but the carbon covered tip started to glow at higher temperatures because of the longer duration of hig load and rpm. that would be perfect to cause detonation. maybe the piston was already shot a long time ago,before i bought the car. The upper pistong ring still seems to be sealing so in theory it could run. all that guessing, i think i can better stop thinking theories and just fix it and get it over with.. grin Any reccomendations about what engine oil to use while running in the new pistons and rings? I have 2 jugs of Shell Helix Ultra 0w40 wich i intended to use next oil changes, but i have other cars in maintenace where i can use it in too.
 
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The Shell is fine but a bit pricey for such a short run, any 10w40 will do just smear a thin coat of Molykote G-n on the main, rod bearings and cam lobes at assembly. Put oil on the piston rings, skirts and cylinders with an oil can then run the engine for 20 min at about 1,000 RPM if you are using the old cams then change the oil and filter.
 

Tommiee

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Thanks trav, have to check if i can get some cheap 5 or 10w40 then, prices are sky high here in holland so I order my oil in Germany @ oil shop center.de or motorenoel100, but my order has to be big enough because otherwise i pay 10 euro for shipping for only 1 jug of oil..
 

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Yes @ MiH, it is a nice thrill. Didn't had her maxed out yet, but vids on youtube show 280/290 @ the same car with similar power
 

Tommiee

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Would there be any benefit running a group IV or V oil in place of the Shell ultra after running in the piston rings? I can use the ultra for running in the cupra and in our second car, a '98 Suzuki Alto 1.0 with only 30k miles. Here's a list of group 4/5 oils and the price Motul 8100 X-cess 5w40 Spezifikationen und Freigaben: BMW LL-01 Fiat 9.55535 - H2/ M2/ N2/ Z2 MB-Approval 229.5 / 226.5 Porsche A40 PSA B71 2296 Renault RN0710 / RN0700 VW 502 00/ 505 00 ACEA A3 / B4 price per litre: 5.20 euro Motul 8100 X-clean 5w40 Freigaben & Spezifikationen: API SN / CF ACEA C3 ACEA A3/B3 BMW Longlife-04 FIAT 9.55535-S2 Ford WSS-M2C917-A GM - Opel dexos2 MB 229.51 Porsche A40 Renault RN0710 / RN0700 VW 502 00 / 505 00 / 505 01 price per litre: 5.60 Aral Supertronic 0w40 Spezifikationen/Freigaben: API SN/CF ACEA C2, C3 MB-Freigabe 229.31/ 229.51 BMW Longlife-04 erfüllt Fiat 9.55535-S2 Price per litre: 6.75 euro Castrol EDGE 0W-40 A3/B4 TITATNIUM FST Freigaben & Spezifikationen: SAE 0W-40 API SN/CF ACEA A3/B3, A3/B4 BMW Longlife-01 entspricht Ford WSS-M2C937-A MB-Freigabe 229.3/ 229.5 Porsche A40 VW 502 00/ 505 00 Price per litre: 7.00 euro
 
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I always liked the Castrol products in Germany, in fact I never used anything else in my own vehicles. Aral was Mobil 1 at one time but now I believe its a Castrol product also as BP owns both.
 

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It's going slow because we have to do it in our spare free time at the garage. it's also my third car so i don't have to rush things. Friday we're going to pull the pistons out and disassemble the head. then i'm probably taking the head home to clean everything nicely.
 

Tommiee

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so the piston rings are, except the oil control ring, all stuck on the piston of cilinder nr.4 no wonder it consumed oil..
 
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I'm not sure I follow you. Is this the second engine that died on you after first owner already had engine swap? And this is the new, improved one? If you are a VW fanboy (in a good way) please ignore folwing sentences. Sell that VAG thing because you will throw money in it to a no end. They are good at fitting body panels and interior trims but absolutely know nothing about how to make engines. Look for some mk2 FL Focus ST with that beautiful Volvo five. Then you will see what a fast and durable hatch is.
 
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Tommiee

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Nope this is the first engine that dies on me. First owner had the engine replaced because he wanted the CDL engine in it, because these can handle more power. Save me that anti VAG talk please, i'm not here to get my car bashed, just to share some of my experiences with the repair and for some helpfull answers to my questions. Ps. You mean those between the cilinder line cracking five's in the ST? Nah, thanks. They sound sexy though.
 
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Originally Posted By: Tommiee
so the piston rings are, except the oil control ring, all stuck on the piston of cilinder nr.4 no wonder it consumed oil..
I would think that with that sort of detonation and force on the hot piston the ring lands have been hammered a little possibly making them tight on the rings. Take a ring off one of the other pistons break it and see if it is a tight fit all the way around in the grooves of this piston. Just a thought, not saying it is so. BTW nice care and a great engine, this sort of thing can happen when you start tuning the engine and those who do it accept it, it has always been the case no matter who made the engine.
 

Tommiee

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Thanks trav, definately going to do that what you say with the rings. It's an expensive hobby but i think it's worth it. I'm even enyoing this repair for the sake of trting to find out what really happened. Thanks for your helpfull posts Trav and the rest
 
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