I think it is fooked

[audiman]

Mate sounds like you have a cracked head somewhere if the gasket looked OK. But that gasket should be bone dry before its clamped down. With the head off its easy enough to change the rings and rods. Would be easier with the block out of the car, but it can be done in situ.

Getting the head tested shouldn't be to bad, but you will need to strip it down completely, again

Once this is done, send it off and have it crack tested, should cost about 35+VAT. Dont know anyone in your area that does that sort of work so thats down to you, sorry!

[A6 AVANT]

Definitely get that head crack tested, the people who did your head the first time should have done a pressure/crack test as part of the rebuild. Some heads need to be stripped down to be pressure tested, I had a mazda 2.2 diesel head done last week that needed stripping to be tested. I know it's a bummer but it has to be done.
Before taking out pistons/con rods etc. make sure you mark each conrod and cap before removing. I normally use a dot punch and on the side of the rod near the nut I dot them with the relevant numbers. Also make sure you get them the right way round when refitting. You will need a piston ring clamp to fit the pistons back in when new rings have been fitted.
Before removing pistons you can pour oil in the bores, about 1 cm deep in each one and if you have worn rings etc. the oil will drain away in an hour or so.
HTH
Chris

[porkkis]

Originally posted by Doug_RS2
When i have the sump off - is it an easy job to change the rings and conrods?

And can it be done without taking anything else off the car?

You can push the pistons out just by opening the big ends.
BUT it would be very advisable to hone the block if you're planning to replace the rings.

[S2central.net]

Agree on honing - there isn't much point in changing rings if the bores aren't honed.

**** or get of the pot <Sorry to use the vernacular - but you get the point>



Paul

[SteveH]

Doug,

It may be a pointless excersise replacing the rings without honing the bores. If you in that deep, a full rebuild is the best option.
With new (lighter) rods you will need to get your crank balanced too.

[Doug_RS2]

what is invloved in honing the bores?

I didn't realise the crank needs balanced if the rods are changed!

Maybe I won't be doing this just now.

[S2central.net]

Honing is a machine shop job. The block needs removed !

Cross-Hatch-Honing is a technique with a specially shaped tool that is inserted in the piston bore such that a criss-cross pattern is lightly etched into the bore. This refreshes the surface such that it is suitable for new piston rings.

Kinda hard to explain actually - need to see the effect to really understand it... Tried any web searches yet ?

Paul

[Greg_S]

Doug,

Honing the bores is done using a tool with three abrasive stones on it on sprung arms. this has a drill type attachment on.

There is some lubricant used while you do this and with the abrasive turning on the drill it is moved in and out of the more to smooth the edges and ensure that it is smooth from top to bottom so that your new piston rings will seal correctly. The bores do need to be inspected first to ensure that they are still the correct shape and havent been ovulated etc.

Greg.

If your at the next meet my dad will be able to explain it to you in full detail

[Greg_S]

Doug,

there is a bore honing tool for sale on ebay if you want to see what i made a hash of describing. lol

Bore Honing tool

Greg

[Doug_RS2]

Ok - I see what you mean - I am going to get someone out to look at the cylinders and do that.

The pistons and rods are out the car now. Just waiting for parts.

[Doug_RS2]

Update:

Took head to a differnet company - Agra Engineering in Dundee - recommended by Mike - They were the best engineering company I have ever seen - they are goint to pressure test the head and skim it. They said the previous skim was not smooth enough for a metal head gasket. They are also putting in a timesert into my head - they don't like helicoils.

Best bit was them taking me round the factory showing me all the machines and what they do. Also showed me a few engines and the engines on the dynos. Top company, really friendly and very prodessional - they weren't condescending or "we know more about enignes than you" attitude like the last place.

My block is coming out - it is the only way to do the honing properly but there is more to this - the cylinders are scored so the block is going to require more work - I expect getting it rebored and larger pistons/ rings will be the case - might as well do it now - IS this the norm with scored cylinders? Where do I get oversized pistons? Just Audi? I'll know more after I take the block to the mavhine shop.

[Paulm]

Doug

I agree very good company they have a smaller Agra in Banff it is the guys brother. I took my cossie head to Dundee (it was to big for Banffs machine) a couple years ago to get it skimmed they made an excellent job.


Paul

[RSCoupe]

Doug,

Where are they putting the Timesert? Is it for one of the spark plugs? I have heard that a timesert will affect the heat range of the spark plug since it is a different material than the head (steel vs. alum.) thus absorbing heat differently. Whereas the helicoil is also steel, but has much less mass than the timesert. If not for a spark plug, fine, I prefer timeserts over helicoils.

[Doug_RS2]

It is a timesert for the spark plug - I just don't like the helicoil and have no confidence in the guys that put it in.

[A6 AVANT]

Doug, if these guys who now have your head are as good as they sound, ask them about your block and pistons, they may possibly have a supplier.
Worth an ask.
Regards
Chris