Potential Piston/Bore damage

[petemcr 10]

I've just been looking through some pictures I've taken of my bottom end and I just noticed something on piston #1 which I want to ask about, see if anyone has any opinions on this

 

Now, I've not really touched the car in a while, nor put too much money in to it so I'm not exactly deep in to it, but I've just noticed what looks like a chip missing out of the crown of the piston and looking at the carbon on top of it, it looks like something has been rattling around in the cylinder, I'm going to crank the engine and check for bore ware but what I want to know is should I call it quits on the bottom end and try and source a new one

 

 

Opinions?

[Dox 23]

Looks fine to me

 

 

 

Result of a blown turbo, head heavily skimmed and piston tidied up and running again

[petemcr 10]

Well it's just the chips in the piston crown that I was a little worried about and looks like something has been hitting the top

[davidwort 0]

pinking? could that have been caused by pre-detonation?

[Dox 23]

pinking? could that have been caused by pre-detonation?

 

Looks like some debris has fallen inside that cylinder on a plug change maybe, if the bore's not scored and if it was mine I'd not worry about it. It looks like its old damage to me

[petemcr 10]

Looks like some debris has fallen inside that cylinder on a plug change maybe, if the bore's not scored and if it was mine I'd not worry about it. It looks like its old damage to me

 

That's what I was wondering, it has probably been like this for a while hasn't it, I was just thinking should I just replace the bottom end before I start to put it back together or should it be fine.

 

I may just assemble it and see how it runs when it's back together.

[petemcr 10]

 

 

Not looking too good, all the other bores are perfect

[Kevin Bacon 5]

If you can't catch a finger nail in those scores, I wouldn't worry about it.

[petemcr 10]

If you can't catch a finger nail in those scores, I wouldn't worry about it.

 

The side ones aren't too bad, barely catch a nail at all, however the one on the very left is fairly deep and I'd say you'd catch a nail in it. It did burn a little oil when you gave it the beans but it wasn't too bad, I presume if I put it back together I'll just be back to burning off oil again?

 

I've found someone who's selling a 2.8 VR fairly cheap, I'm wondering if it would be possible to get the 2.8 and have it bored out to 2.9 and use my pistons, provided they're not damaged on the side of the piston, just as an option

[Kevin Bacon 5]

Yep, it would I'm afraid.

 

Yeah reboring a 2.8 is an option. The pistons will come up like new if left in an automotive acid bath for a day. Try and find machine shop that does the factory correct honing though, or it could end up still being an oil burner! In other words, I wouldn't use a flex-hone or anything like that.

Probably a good idea to use new piston rings and replace all the bearings and seals whilst you're there.

[Jim Bowen 1]

Hoping to drop my bottom end off with Vince at Stealth and get his advice on it.

 

I could still see the cross hatching pattern in mine, but could feel a lip where the piston reaches the top and doesn't go past it. (if that makes sense)

[petemcr 10]

I need to decide what I'm going to do now, do I just get the head back on and get it running for now till I decide, I didn't really want to have to remove the bottom end but if it's going to start going in to getting it out and having it machined etc.. Do I just bite the bullet and go for the 2.8 24v conversion and loose that lovely vr6 sound.

 

It has never felt down on power while I've had it, so if I put it back together now to use over summer would it really cause that much damage?

[Jon_vr6 1]

Is it your daily? If not id put it all back together and worry about it when it goes pop

[petemcr 10]

It's not my daily, it was until the head gasket went, I'm assuming with the bore marks then that it will go pop?

[Byrd 10]

One of my pistons had the same chips out the top of it and- maybe about 50% worse than that, and I was advised that it was from Pinking/ pre-ignition. Shouldnt cause any problems if you were to re-use those pistons with new rings..............I went ahead and ordered new pistons from MAhle and rebored the cylinders. Not a trace of oil burning now, but had to remove the head after rebuild to replace valves due to worn valve stems. Good Luck!

[petemcr 10]

Ok, sorry for the poor angle of this video but it was in the best place to hear it, now it's pretty apparent now that the "steam engine" as my friends have come to call it, but I noticed today that it sounds like it may be knocking as well, or it may be the exhaust gaskets knocking around... But after seeing the bore wear I'm now wondering,

 

[Kevin Bacon 5]

VR6s do rattle a bit when cold. Bores 1 & 6 ovalise before the other 4 do and it's them that make the most noise.

 

So have you put it all back together then?

 

Rebuilding a VR6 doesn't make economical sense anymore, imo. Mahle are a pain in the neck for getting pistons from, especially in 82.5mm over bore size. It can take 1 week, or it might take 9 weeks, or it might take 4 months. And it's going to be well over £1000 in pistons, bearings, chain gear and gaskets etc before the machine shop even see it.

 

I'd rather put a low mileage engine in than rebuild one.

[petemcr 10]

Well this is my issue, I think I'm gonna just put it back together and see if it is knocking or if it's fine for now, then start looking at either a new block with low miles to drop in it, or just the vr6 from the v6 4 motion and just bite the bullet and use the money for that

 

It hasn't had issues with knocking before so I'm just going to see how it runs once back together and hope for the best for now

[Kevin Bacon 5]

Sounds like it's just tired.

 

It's worth checking with the dealers as sometimes they have engines they're trying to get rid of. It's also sometimes sold as new old stock on ebay. Someone on here got a brand new block (with pistons and crank etc) that way a while back for little money.

 

I would try a 24V first before committing yourself as you might not like the power delivery. It's completely different to a 12V!

[Dox 23]

Sounds like it's just tired.

 

It's worth checking with the dealers as sometimes they have engines they're trying to get rid of. It's also sometimes sold as new old stock on ebay. Someone on here got a brand new block (with pistons and crank etc) that way a while back for little money.

 

I would try a 24V first before committing yourself as you might not like the power delivery. It's completely different to a 12V!

 

http://www.ebay.co.uk/itm/161145489408?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

[petemcr 10]

Is it like the R32's by any chance? A couple of people I know have Golf R's and I know the 24v Is a baby R32 so I'm guessing the lower delivery is all down low, one of theirs which has had work done is really twitchy, you touch the throttle and it just flus off.

 

Funny enough there is a bottom end on eBay at the moment that has everything bar the pistons for £400 or so

[petemcr 10]

http://www.ebay.co.uk/itm/161145489408?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

 

Hahaha and there it is

[EJ Taylor 22]

EJ - that pic cracked me up ;)

 

Did i hear... Damaged Boar?

 

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[g0ldf1ng3r 15]

Did i hear... Damaged Boar?

 

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:D

[seanl82 23]

Did i hear... Damaged Boar?

 

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Here he goes again. Someone ought to change your username to something funny EJ. :silent: