1.4 tsi CAVE melted piston

[queen]

Sorry to hear that,
it was probably the injector. There was this issue with the early models, since then VAG released upgraded injectors that rectify the problem. You should get them. The older ones could drip when stationary and had a narrow spray pattern, the new ones have a wider spray pattern that results in better combustion.

 

[PoloGTI]

Hi Queen,

Thank you for the kind reply! I left the injectors for a test and I will know more about their condition later on today. Do you by any chance have the part number of the latest revision injectors for our cars?

 

[dm222]

well, for decades a 1.4 engine would have around 80 to 90HP, suddently they decide to duplicate that value, obviously nothing good could come from that...

 

[Sonofzelda]

Duplicate? Duplicate?
I agree. If you want two for the price of one go to Tesco.

 

[Big-Pete]

Hi Queen,

Thank you for the kind reply! I left the injectors for a test and I will know more about their condition later on today. Do you by any chance have the part number of the latest revision injectors for our cars?

03C906036N afaik

 

[PoloGTI]

well, for decades a 1.4 engine would have around 80 to 90HP, suddently they decide to duplicate that value, obviously nothing good could come from that...

Well, power is not the issue IMO. The engine should easily be able to handle 180 and then some. many examples even within vw group. Problem is the design flaws of the CAVE engine. As Pete said, it is a lottery-there are also some good examples of that engine, but all in all is a problematic engine.

 

[PoloGTI]

03C906036N afaik

Hi Pete,
Thanks for the quick reply, I checked the part number of my injectors it is 03C906036M, so there is one more revision after that. I just picked up mine-they were tested and the results are great-all 4 injectors flow the exact same amount, they do not leak when stationary and have a very good spray pattern. So, I will reuse them.
I will pick up the car next week and let you know how it runs. Should be OK. Full test will be after I break it in after 3,000 km.

 

[PoloGTI]

Just got back the block from the machine shop. Cyl. #2 was sleeved and all cylinders were honed. Looks good, the sleeve is barely noticeable. Hopefully, next week the car will be up and running.

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[VeeFource]

Looks to me like your spark plug was either overtightened (which caused the thread to fail) or too loose (which allowed the hot gases to melt things). I've only had a brief look but all those fault codes look like they support something like that happening.

 

[PoloGTI]

Hi VeeFource,

Thank you for the feedback. That is a possibility, however I removed the spark plugs myself after the incident and the spark plugs were neither overtightened, nor loose. Perhaps, I will never know the cause of this failure. I found a few other cases of broken spark plug tip and melted piston on the internet, but the cause was unclear. Some cars got a new engine, some were out of warranty and did not report back if they fixed them or not. In any case, I have fitted the latest revision spark plugs NGK 96209 SIZFR6B8EG and plan on changing them on 20,000 km intervals.

 

[PoloGTI]

Just wanted to update you guys on the car as you have been helpful and responsive. I appreciate it!
The block was honed and cylinder #2 was sleeved. We wanted to change just the melted piston however it turned out that VW stop making the pistons fitted to my car and the new revision pistons are 10 grams heavier. So, I did not want to disbalance the engine by fitting one heavier piston, which also had a different design. The new piston has a even shorter skirt than the old one but the skirt is thicker and the piston as a whole looks stirdier. The latest revision piston part number is 03C107065BF. This piston is made by Kolbenschmid (original pistons were Mahle) and the Kolben part number is PM004900. I got Kolben pistons (not VW which are exactly the same but price is double) for 115 EUR each. Had the injectors cleaned and tested again. Had the catalytic converter machine cleaned. The head was dismantled and cleaned. All new gaskets and a timing chain with tensioners. The car is as good as new, runs smoothly. I hope the new pistons will rectify my oil consumption issue now.
I will report back after the break in period of 3,000 km

 

[Cosmin cosu]

Hi Pete,
thanks for your reply and the offer for the long block, but my engine can be repaired. The head is off and already sent to a machine shop. Visually, there is no damage, but they will check it thoroughly anyways. I have ordered a new piston and once the whole engine is out, the block will be sent for repair. I will fit new plugs apparently (and coils if needed). I am also planning to have the injectors tested. Will check the catalytic converter as it may have melted...A hefty bill is coming My mechanic was puzzled as he had never seen a piston melt like that on a gasoline engine (diesel, yes) the car had a 3 year warranty only, so no warranty. i am really frustrated as i rarely push the car. How can it be so fragile? always put 100 RON, gas, had never had misfires before while driving. Really questioning wheather to sell it after I repair it. It is my wife's car. I drive an APR Stage 2 Audi 2.0 FSI quattro with 290 hp and that car has never missed a beat in the past 3 years, and I drive it very hard...

P.S. You have one mean Bocanegra

100 Ron? Romania?

 

[PoloGTI]

Hi guys,
Just did an oil change after the first 11,000 km after changing the pistons. The car has used only 0.5 litres in 11,000 km-I have not added a drop of oil. Filled it up to the max and before the oil change it was about half way down on the dipstick. Needless to say, I am very happy I did have some misfires at high rpm-6500-6700 and it turned out that the reason was a seriously clogged catalytic converter. I got a custom downpipe made with HJS 200 cell catalytic converter and oh boy, does the car pull No more misfires, just pulls cleanly to 7000 rpm and spins my winter tyres in 3rd and I am not even tuned (stock tune). With the HJS cat, I do not get any codes for catalyst efficiency below threshold, passes the readiness test easily on the stock tune. I might get an APR tune down the road, or go to TMG Performance in Thessaloniki.
I think that the clogged catalytic converter might have been the reason for the broken spark plug tip and melted piston-backpressure, respective high combustion chamber temperatures. So, if you get the catalyst efficiency error on the stock cat, be careful taking your car to redline in higher gears.
Downpipe in 2.75 inches (70 mm) from turbo to catalyst and 63.5 mm (2.5 inches) from cat to the rear silencer. I got a resonator as the car sounds trashy without it. If anybody is interested, I can post pictures of the downpipe system.

 

[Nicolai Rexen]

Hi guys,
Just did an oil change after the first 11,000 km after changing the pistons. The car has used only 0.5 litres in 11,000 km-I have not added a drop of oil. Filled it up to the max and before the oil change it was about half way down on the dipstick. Needless to say, I am very happy I did have some misfires at high rpm-6500-6700 and it turned out that the reason was a seriously clogged catalytic converter. I got a custom downpipe made with HJS 200 cell catalytic converter and oh boy, does the car pull No more misfires, just pulls cleanly to 7000 rpm and spins my winter tyres in 3rd and I am not even tuned (stock tune). With the HJS cat, I do not get any codes for catalyst efficiency below threshold, passes the readiness test easily on the stock tune. I might get an APR tune down the road, or go to TMG Performance in Thessaloniki.
I think that the clogged catalytic converter might have been the reason for the broken spark plug tip and melted piston-backpressure, respective high combustion chamber temperatures. So, if you get the catalyst efficiency error on the stock cat, be careful taking your car to redline in higher gears.
Downpipe in 2.75 inches (70 mm) from turbo to catalyst and 63.5 mm (2.5 inches) from cat to the rear silencer. I got a resonator as the car sounds trashy without it. If anybody is interested, I can post pictures of the downpipe system.

Hey where did you get your custom downpipe and the cat from

 

[PoloGTI]

Hey where did you get your custom downpipe and the cat from

Hi mate,
I got the downpipe made by a local shop. They do exhausts, exhaust manifolds and intercoolers. Their work is top notch. Ckeck teir website and give them a call. They can send you pictures of my downpipe and if you like it, they can make you one and ship it to you. Their prices are very reasonable too.

http://www.extreme-tuning.bg/en/home

I did another oil change-22,000 km since the rebuild, car runs great, about 300 ml oil consumed in 11,000 km, which is great.

 

[Nicolai Rexen]

Hi mate,
I got the downpipe made by a local shop. They do exhausts, exhaust manifolds and intercoolers. Their work is top notch. Ckeck teir website and give them a call. They can send you pictures of my downpipe and if you like it, they can make you one and ship it to you. Their prices are very reasonable too.

http://www.extreme-tuning.bg/en/home

I did another oil change-22,000 km since the rebuild, car runs great, about 300 ml oil consumed in 11,000 km, which is great.

Cool I have send them an email. I would like to see photos of the exhaust if u have I'm currently running cat back from cobra

 

[PoloGTI]

Cool I have send them an email. I would like to see photos of the exhaust if u have I'm currently running cat back from cobra

I will find the pictures and will attach them here. The downpipe that I have will mate very well with cobra as it is similar design to the cobra downpipe. It is 2.75 inches from the turbo to the catalytic converter(HJS germany) and then 2.5 inches to the resonator( you can choose non resonated but for me it is too noisy) and then it mates to my stock catback

 

[PoloGTI]

I will find the pictures and will attach them here. The downpipe that I have will mate very well with cobra as it is similar design to the cobra downpipe. It is 2.75 inches from the turbo to the catalytic converter(HJS germany) and then 2.5 inches to the resonator( you can choose non resonated but for me it is too noisy) and then it mates to my stock catback

By the way, what car do you have ? seat, vw or skoda? They are all the same anyway.

 

[Nicolai Rexen]

By the way, what car do you have ? seat, vw or skoda? They are all the same anyway.

Aha, well mine is a seat Ibiza cupra 6j 2013 with a brand new cthe engine because of a cracked piston.
I currently have a non resonated cobra I like it loud, but it's not too loud for me. I m aiming for the 300 bhp I just need to figure out which parts to change. Since I don't want to change parts just to change them

 

[PoloGTI]

Aha, well mine is a seat Ibiza cupra 6j 2013 with a brand new cthe engine because of a cracked piston.
I currently have a non resonated cobra I like it loud, but it's not too loud for me. I m aiming for the 300 bhp I just need to figure out which parts to change. Since I don't want to change parts just to change them

OK, I understand. You should easily be able to get 300 hp with a hybrid turbo. Call https://www.tmg-performance.com/

You will need their hybrid turbo, decent downpipe (the one I recommended will be fine) without catalytic converter if emissions is not a problem and no resonator, tmg or vw racing intake, wagner or tmg intercooler, tmg blow off valve, tmg remap, R8 coilpacks with the tmg adapter and thats about it. I would also get transmission remap with launch control and the tmg kevlar dag clutch pack. You can pm Queen, she can help you as she had a really powerful 1.4 TSI