Engine replacement vs Engine rebuild( forged pistons and rods) pros and cons

[Jamie_Ldn]

Hi guys

As some of you may know I had a right grilling for trying to get around someone else fixing my car. I figured it being stock and Ive had the car just about three months, I could go back to the dealer and see if they could fully or partially contribute to the repair bills but anyway.

The car started off with a small misfire. When it happened no one realised but me ( mates thought it was my imagination) which happened not last Sunday the sunday before (27-04-2014). It felt more like a hiccup but even so I was little concerned. Following I took it to mates to get plugged on the VAGCOM to see whats happening out of curiosity as I was told you can still scan the car for problems without warning lights popping up. It came up with misfire from cylinder 2 and cylinder 4. I assumed it was down to dead plugs as it was due round about 2000 miles previous. I got the misfire cleared and it didn't come back again as I drove it home. I booked a service in for the Friday evening for after work. Bare in mind I don't drive my car to work during the week as I commute on the oyster card ( before I get told off again) and didn't plan to touch my car till then.

Wednesday came and there was the first frept meet. I thought lets have a look and it was a good turnout. Fast forwarding to on the way home as you do from most meets you your pals maybe some randoms will have a little boot. I knew my car wasn't 100% so I let the turbo spool up just as we were pulling off the motorway which was the first exit after getting on to it and THEN the lil hiccup came back again. I let off completely and allowed my mates to carrying on ( don't wanna ruin their fun). As I crawled home BIG hiccup happened I felt a great loss of power. The EM light started flashing going bananas.

Almost had a heart attack watching it do that so I pulled to the side of the road and the car sounded like an old banger that was being started up on a ice cold morning.

I crawled home probably doing 15-20mph. Took me an hour to get home. Left the car alone thinking the worst ( not as bad as needing a new engine)

Friday came and had some spark plugs and coil packs sent to the garage before I even left. We changed coil packs first it wasn't those. So as you do we assumed it would be plugs. cylinder 1 changed. but when we got to cylinder 2 it was then that we realised that something definitely wasn't right. Spark plug had broken and melted away as it was completely burnt. We proceeded to changing the rest anyway and started the car up. Exact same misfire but when we scanned it this time the misfire only came from cylinder 2. So I guess I coulda have been right in saying it need plugs changed in the first place ( shoulda just hitched a ride to FREPT Walking Sad ) Did the coil pack test again anyway and it was still the same. ( was pointless doing the test again right). So we tried looking inside through the lil hole to see if we might see the broken part of the plug and no joy.

Next off we did a compression test. cylinder 1, 3 & 4 averaged at 150psi. and cylinder 2 was at 5psi and pushed that much out because we sealed it with oil.

At this point the diagnosis was that piston was cracked or melted but we will never know until we actually open the head ( currently looking for someone to open the head to see the actual damage, My mates that helped me look at my car they deal with Volkswagen engines but the most they've done on TFSI is service and maintenance so I'm not too comfortable for them to go all frankenstein on my car despite my block/head being in the graveyard)


NOW TO THE ACTUAL QUESTION ( hope I haven't wasted your time too much)

Now I'm thinking worst case scenario , Replacement Engine, Engine rebuild or engine rebuild with forged internals

Ive come from a Corsa 1.8sri as my first to a bright Yellow Seat Leon Cupra TFSI. Im still learning as I go about the mechanics of a car so before anyone decides to grill me just know I'm a little uneducated in this department.

So Ive looked around for reconditioned engines/ engines out of salvaged cars that share the same or similar engine and I be looking at anything between 1200- 1800. I been on engine websites, ebay, seen nothing on here and a spares garage

I went to the bmw vs mercedes meet on Monday ( in my mates car lol) I spoke to this dude with a fro in a bagged Leon. Some may know who I'm on about lol . He recommended that with the money I'm going to spend on buying a new engine I may as well top up and get forged pistons and rods. Again I know jacksh*t about the mechanics of a car so I would also need to have someone carry out the work for me. That same birdie also told me that parts and labour included I would be looking at 2500. Im not looking to go big turbo no time soon it hasn't even been a thought till this was brought up .

So my question is could I have potentially damaged something else in the event piston is cracked or melted or maybe the piston wall ?

Aside from forged pistons and rods what else would I need for an engine rebuild?

What sort of compression changes would I need to make in the event that I do go big turbo for example GT28 or GT30 ?

Is there anything else I may need to consider ?

Finally who are the people to see without ripping me completely off? Im from London but getting the car to an engine specialist isn't a problem.

Jamie

 

[Ben750]

If it was me, the first thing I'd be doing is getting the head off (or getting someone to do it for me) and suss out what the actual damage is. It's possible that the bore is scored from any bits that were floating about in there. I'd be wanting a look at the turbo too to see if any bits have damaged that. That's just for starters, you drove it for quite a bit after the big hiccup, there's chance off it wrecking all sorts of bits. Because of that I'd be considering a replacement engine, but they won't come with a turbo. Best to see what you're actually dealing with first.

Can't really help on the rest, but there's plenty on here with way more knowledge than me.

 

[Jamie_Ldn]

If it was me, the first thing I'd be doing is getting the head off (or getting someone to do it for me) and suss out what the actual damage is. It's possible that the bore is scored from any bits that were floating about in there. I'd be wanting a look at the turbo too to see if any bits have damaged that. That's just for starters, you drove it for quite a bit after the big hiccup, there's chance off it wrecking all sorts of bits. Because of that I'd be considering a replacement engine, but they won't come with a turbo. Best to see what you're actually dealing with first.

Can't really help on the rest, but there's plenty on here with way more knowledge than me.

Cheers pal. Im actually looking into getting the head opened up to see what the damage is. I emailed Alex at AKS tuning this morning. Just waiting for him to get back to me so I can start prepping the car to get recovered up to his workshop.

 

[porksword28]

Best place to take it I'm sure he'll advise you on the right course of action for you!

 

[richicupra]

Aren't the Cupra internals forged anyway? (or at least uprated from the FR/TFSI)

 

[robdf2]

I'm would say injector number 2 bit the dust and piston number 2 has melted or could be your rocker arm on piston 2 , if the Cupra engines are over revved the rocker arms can bend , so your exhaust valve could be sitting in the middle of your piston.

Only way to tell is take the head off , the only thing that will determine a rebuild or new engine is whether the bore has been damaged and the cost of refurb vs new engine.

Good luck buddy keep us updated.

 

[razz247]

i'm going through the same with my leon buddy, my 3rd piston hit my spark plug, causing piston to crack and cause a couple of gouges. Looking into forging myself but im only running stage 2+ and dont plan on going any more so i'm undecided ! Be nice to compare with the outcomes

 

[Jamie_Ldn]

i'm going through the same with my leon buddy, my 3rd piston hit my spark plug, causing piston to crack and cause a couple of gouges. Looking into forging myself but im only running stage 2+ and dont plan on going any more so i'm undecided ! Be nice to compare with the outcomes

I get you. Im skeptical as well as in one hand I could look hard enough and get a CDL engine for about 1500 pound maybe or less not knowing whether or not it could possibly go bang again not knowing its history or a new fault may come up or a case of where the mileage is slow I may have to eventually change the cambelt and water pump again


or

Do I just get the forged pistons and rods done and that way when I do get mapped my torque doesn't have to be restricted at stage 2+ without the worry of rods bending and also the possibility of being Garret ready if and when i get bored of 360+ bhp and wanna go past the 400bhp mark. Im not a speed junkie or nothing but it would be an experience to have a garret turbo'd car especially as their only a few leons in the country with garrets bolted.

im in two minds, already received a quote from TSR performance and AKS tuning nd I've also come across quotes of CDL engines.

I mean they say the TSI engine is a revised TFSI and essentially when their mapped they respond well and give off some very interesting figures.

Its so difficult when you've only had the car three months and want the car on the road asap but at the same time you miss the opportunity to go bigger power

 

[razz247]

Exactly how i am mate, like ya say if you put forged in and rebuilt asleast you know its all right and literally brand new. And ready for bigger things if you want it.

 

[Shawn James]

Hiya pal looks like we all going threw same problem I've had my seat cupra apr stage 2 + 4 week and it keeps oiling up number 3 cylinder I was gonna buy a used engine but the garage steered me away saying u could have same problem a month or so down line so mines booked in Monday for forging tfsi engines are good if looked after properly I'd go forged mate for the extra few hundred pounds extra than risking a 2nd hand engine mate

 

[Legojon]

Hiya pal looks like we all going threw same problem I've had my seat cupra apr stage 2 + 4 week and it keeps oiling up number 3 cylinder I was gonna buy a used engine but the garage steered me away saying u could have same problem a month or so down line so mines booked in Monday for forging tfsi engines are good if looked after properly I'd go forged mate for the extra few hundred pounds extra than risking a 2nd hand engine mate

Hi, might be a good idea to start a new thread in the MK2 section with your issue as the original thread hasn't been active for 6 years.