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Author Topic: Cylinder Bore Scoring  (Read 4553 times)

Offline rhyseyness

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Re: Cylinder Bore Scoring
« Reply #15 on: February 02, 2023, 01:53:11 pm »
how was it running before the cambelt went? burning much oil? noisy ? down on power ?
grant you the bore scoring is far from ideal, but it didnt happen just at the point your cambelt let go afaik. 
an suboptimal option is to get a 2nd hand head and just bolt it all back together

This thought did cross my mind.
It ran great before the cambelt failed. Very little oil consumption- would need about an extra litre between services at 8k miles.
Didn't notice any drop in power over the time I've owned it.
Little bit noisy but nothing that worried me. Quieter than a lot of the one's I've heard people asking for help with and being told "they're just noisy, don't worry" on Facebook groups!

I can't bring myself to whack a new head on knowing that the damage to the cylinders is there.
I believe with damage like that it's only a matter of time before the oil consumption is through the roof and worst case the engine gives up all together.
If I just wanted it to get me by until I could afford an upgrade, I'd do exactly that, but I really do love this car and can't see myself getting rid of it for a very long time.
I'd also feel awful selling it to anyone at the end of my time with it if I knew the state the bores were in.
With a new engine, the only major part of the drivetrain that won't have been replaced is the gearbox.

I had plans for a full suspension overhaul to a full Bilstein coilover set and Superpro ARBs, TT top mounts etc. early this year, which have been pushed back a bit now obviously!
I feel like once that's done (and if I get this new engine), pretty much every major component of the car will be near new and if I continue to take care of it, it should last me a very long time, which ultimately is what I want.

Offline john_o

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Re: Cylinder Bore Scoring
« Reply #16 on: February 02, 2023, 03:33:19 pm »
its in your head now, I get it. but honestly ive seen far worse engines than yours.
if you can get one good condition for little money, then no harm trying (other than your time and some gaskets)
then you have options and a working car ...
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Offline pudding

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Re: Cylinder Bore Scoring
« Reply #17 on: February 02, 2023, 03:45:55 pm »
Scratches like that normally happen from overheating.  The piston ring gaps close up and they have no where to go except up or down, which breaks the ring lands, or expand outwards, which scratches the bore.....or a combination of the two.  Pretty common on remapped engines (most folk don't realise they are driving around with broken pistons until it starts smoking badly) but it never happens on standard engine unless cooling issues occur and it over heats.

Sorry to see this btw, always a gutting experience seeing a paper weight of a block after lifting the head.  It isn't recoverable financially as you'll need oversized pistons and the machine work to suit, which is mega money.

I think chancing a second hand engine is the most cost effective way forward.  Rebuilds and/or new blocks from VW are easily around the £3K mark.

As far as I know car isn't and has never been mapped, but that is very interesting as I had an overheating issue previously due to dead radiator fans, so could well have been the cause!
Thanks for the info, very good to know.

I've had a ballpark quote from AKS for a full forged rebuild with rebore and they reckon about £5.5k.
As you say, mega money, and even if I did have that laying around, they're not taking bookings at the moment.
They've recommended a couple of other garages who I'll contact and see what they reckon.

I'm leaning towards a reconditioned engine from "volksmine" which looks like it'll be about £2.5k for the engine plus all the other bits (seals, fluids, cam follower etc.) bringing it up to just over 3k.
Obvious downside is that I'll have to do all the work myself.
Still not cheap, but that's near enough a brand new engine which seems worth it to me.
https://www.volksmine.co.uk/audi-a3tt-20-petrol-200-bhp-4-cylinder-bwa-re-con-engine-166-p.asp
Anyone with first hand experience of this company would be massively valuable!

Was probably the worst I've ever felt about my car when I saw the scoring after lifting the head.
It put my brand new clutch slipping immediately after I put it in last year to shame! (Since replaced with a Helix performance one)

Yeah AKS Tuning are bloody expensive.  Totally not worth £5.5K.  You can get a brand new genuine VAG CDL engine from TPS for less than that, which will be a lot better than any aftermarket rebuild!

Anyway..... having looked at the pictures again in more detail (was just a cursory glance the first time) I think pistons/rings can be out ruled. If the rings had butted together and gouged the bores, the gouges would be the full length of the cylinder, but your gouges are all over the place and different lengths, and even beyond the wear ridge!!

I'm now thinking it was foreign object/debris damage.  Something got into the cylinders and got wedged between the pistons and cylinder walls. Something hard like grit because they're pretty serious gouges for bits of carbon falling off valves etc.....then again.....baked carbon is hard.  It's what diamonds are made of after all.


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Offline rhyseyness

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Re: Cylinder Bore Scoring
« Reply #18 on: February 02, 2023, 05:52:16 pm »
Scratches like that normally happen from overheating.  The piston ring gaps close up and they have no where to go except up or down, which breaks the ring lands, or expand outwards, which scratches the bore.....or a combination of the two.  Pretty common on remapped engines (most folk don't realise they are driving around with broken pistons until it starts smoking badly) but it never happens on standard engine unless cooling issues occur and it over heats.

Sorry to see this btw, always a gutting experience seeing a paper weight of a block after lifting the head.  It isn't recoverable financially as you'll need oversized pistons and the machine work to suit, which is mega money.

I think chancing a second hand engine is the most cost effective way forward.  Rebuilds and/or new blocks from VW are easily around the £3K mark.

As far as I know car isn't and has never been mapped, but that is very interesting as I had an overheating issue previously due to dead radiator fans, so could well have been the cause!
Thanks for the info, very good to know.

I've had a ballpark quote from AKS for a full forged rebuild with rebore and they reckon about £5.5k.
As you say, mega money, and even if I did have that laying around, they're not taking bookings at the moment.
They've recommended a couple of other garages who I'll contact and see what they reckon.

I'm leaning towards a reconditioned engine from "volksmine" which looks like it'll be about £2.5k for the engine plus all the other bits (seals, fluids, cam follower etc.) bringing it up to just over 3k.
Obvious downside is that I'll have to do all the work myself.
Still not cheap, but that's near enough a brand new engine which seems worth it to me.
https://www.volksmine.co.uk/audi-a3tt-20-petrol-200-bhp-4-cylinder-bwa-re-con-engine-166-p.asp
Anyone with first hand experience of this company would be massively valuable!

Was probably the worst I've ever felt about my car when I saw the scoring after lifting the head.
It put my brand new clutch slipping immediately after I put it in last year to shame! (Since replaced with a Helix performance one)

Yeah AKS Tuning are bloody expensive.  Totally not worth £5.5K.  You can get a brand new genuine VAG CDL engine from TPS for less than that, which will be a lot better than any aftermarket rebuild!

Anyway..... having looked at the pictures again in more detail (was just a cursory glance the first time) I think pistons/rings can be out ruled. If the rings had butted together and gouged the bores, the gouges would be the full length of the cylinder, but your gouges are all over the place and different lengths, and even beyond the wear ridge!!

I'm now thinking it was foreign object/debris damage.  Something got into the cylinders and got wedged between the pistons and cylinder walls. Something hard like grit because they're pretty serious gouges for bits of carbon falling off valves etc.....then again.....baked carbon is hard.  It's what diamonds are made of after all.

Following this I contacted TPS to see what they could do, because a brand new engine from the factory sounds like a great option if it's <£5k.
Unfortunately, 7 grand, plus a £1200 refundable surcharge! :grin:

I agree the cylinder damage does look more like FOD, but we won't ever know for sure! (I suppose unless I take the bottom end ot bits and find debris in there, lol!
Whether it was the valves or some other debris is another matter, but interesting to know that it can be caused by overheating nonetheless!

Still leaning towards the volksmine option at the moment (recon'd engine), but gonna think it over at the weekend.
Will be sure to keep you all posted!

Offline bobby_fodge

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Re: Cylinder Bore Scoring
« Reply #19 on: February 03, 2023, 09:18:22 am »

https://www.vwt4forum.co.uk/threads/new-engine.1215386/

https://www.google.com/search?q=volksmine&rlz=1C1GCEB_enGB1015GB1015&oq=volksmine&aqs=chrome..69i57j69i60l2.1065j0j4&sourceid=chrome&ie=UTF-8#lrd=0x487a428f98936f2f:0x89d75d26dd448bd1,1,,,,

Thanks!
Reviews look decent apart from a couple.
Those couple do worry me a little bit.
Their feedback on ebay is very positive.
The other forum post I'm not too worried about as I won't be having their garage in Coventry putting the engine in, and there's no complaints about the quality of the engine itself, just the rushed work putting it in; I'll be doing it myself and won't be in a rush!

I've just had a quote from them for my job:
"Thankyou for your enquiry of the BWA TFSI Re-con Engine.

The total cost for the rebuild is £1795 which includes VAT and delivery
+ collection of the old unit.
The build will be completed with a NEW Cylinder Head priced at £1000

The total cost including vat will be £2795

We will be building you a unit from stock. The unit is built to a very
high standard with the uprated oil pump kit and it will have a full 12
months or 20,000 miles warranty.
The build includes a host of new parts including Head Gasket,Bearings
big end+Main,guides,stem seals,Piston rings,water pump,belt kit
"

Seems a reasonable price.
Brand new head (as all the valves are trashed on mine) and a reconditioned bottom end.
12 month, 20k mile warranty.
Bloke seemed decent on the phone.

What do you guys reckon?

Does any of their Ebay feedback cover engine rebuilds or is it just about them posting parts out?

Do you need a new head, can the current one be skimmed etc?

I'd definately get more quotes for the exact same work, including the collection of the current engine and delivery of the new one, from engine builders.

Offline rhyseyness

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Re: Cylinder Bore Scoring
« Reply #20 on: February 03, 2023, 12:37:46 pm »

https://www.vwt4forum.co.uk/threads/new-engine.1215386/

https://www.google.com/search?q=volksmine&rlz=1C1GCEB_enGB1015GB1015&oq=volksmine&aqs=chrome..69i57j69i60l2.1065j0j4&sourceid=chrome&ie=UTF-8#lrd=0x487a428f98936f2f:0x89d75d26dd448bd1,1,,,,

Thanks!
Reviews look decent apart from a couple.
Those couple do worry me a little bit.
Their feedback on ebay is very positive.
The other forum post I'm not too worried about as I won't be having their garage in Coventry putting the engine in, and there's no complaints about the quality of the engine itself, just the rushed work putting it in; I'll be doing it myself and won't be in a rush!

I've just had a quote from them for my job:
"Thankyou for your enquiry of the BWA TFSI Re-con Engine.

The total cost for the rebuild is £1795 which includes VAT and delivery
+ collection of the old unit.
The build will be completed with a NEW Cylinder Head priced at £1000

The total cost including vat will be £2795

We will be building you a unit from stock. The unit is built to a very
high standard with the uprated oil pump kit and it will have a full 12
months or 20,000 miles warranty.
The build includes a host of new parts including Head Gasket,Bearings
big end+Main,guides,stem seals,Piston rings,water pump,belt kit
"

Seems a reasonable price.
Brand new head (as all the valves are trashed on mine) and a reconditioned bottom end.
12 month, 20k mile warranty.
Bloke seemed decent on the phone.

What do you guys reckon?

Does any of their Ebay feedback cover engine rebuilds or is it just about them posting parts out?

Do you need a new head, can the current one be skimmed etc?

I'd definately get more quotes for the exact same work, including the collection of the current engine and delivery of the new one, from engine builders.

I don't think I need a whole new head, but I do need a full set of valves and probably a skim... maybe seat cutting and guides, but I don't have the equipment to measure whether that's necessary.

I've been trying to get more quotes, but very few garages have responded or picked up the phone.
Any recommendations would be greatly appreciated! Preferably SE London, but going to have to ship the motor/have it collected either way so not essential it's local.

Offline rhyseyness

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Re: Cylinder Bore Scoring
« Reply #21 on: March 12, 2024, 05:58:40 pm »
Sorry to resurrect an old thread but realised I hadn't actually posted the final update on this.
I ended up going with a rebuild from TSR Performance (ZRP rods, Wossner pistons, R8 springs, Supertech valves, freewheel sprocket and a new crankshaft (mine was in bad shape)).
Shipped them the engine and they shipped it back around 5 months later. Sent it March got it back in August.
After a few painful weekends with coolant leaks and noises I didn't like, had it back in running again.
All in cost... a small fortune- more than than the car will ever be worth!
Ended up getting new injectors, coils, alternator, thermostat all sorts of other bits.
I think fair to say I didn't appreciate the scale of the job I was taking on, and all the tools I had to get hold of to do this job in the car park of my flat!
I've done just over 3000 miles on the new motor now, including run in, and it's not skipped a beat. Runs lovely!
Looking forward to eventually slapping a bigger snail on it as should be good for big power now!
I'm not going to pretend this was a reasonable financial decision but it's made me very happy!
Now it's capable, I can't wait until it's actually fast! :grin:

For those interested, the build was just over £5.5k. Shipping plus all the other bits I bought, total cost was around £7k and a bunch of my time.