My S2 coupe bit of a rebuild and repair thread.

[B5NUT]

So got the new valves today. Both still available
. valves.jpg

The pipe is still in a good condition but the rust has started to set in.
pipe.jpg

Quick blast and it's come up Ok. Then spray coated in epoxy.
shot.jpg paint.jpg

Now just waiting on ear clips. Audi want almost £4 per clip So ordered a bunch from HCL they do all the sizes so far that the S2 has needed. Shop for Hose Clamps Smart Ties Banding and Clamping Tools for Sale – HCL Clamping UK/Europe (hcl-clamping.co.uk)

They won't arrive until Thursday, so will have to wait to complete the pressure test until then.

[Tractor Dave]

Nice work

[B5NUT]

Cheers Dave. Just wish I had remembered to buy replacement ear clips yesterday

[newsh]

The one you need to disconnect and plug is the breather on the side opposite the Diverter Valve.
Just pull the Zigzag pipe out and plug the hole in the MAF hose.
Saves pressurising the PCV system and crankcase. (You can do a low pressure test with it connected to see there's no leaks but it only ever sees vacuum.)

This is where the DV plugs in and it needs to stay connected and tested.

[B5NUT]

Thanks.

I've just made another plug using an old 14mm socket. Is it better to do the test with the bumper off so you can check out the intercooler?

[B5NUT]

Received the clips today and got the crank case breather system back in the car.

Started the pressure test. I used a Makita 18v tyre inflator to pressurise the system, as I could not be bothered to get the compressor running and get all the hoses out.

test.jpg

Started with a low pressure of 8 PSI which instantly got results. was getting a bubbles from the idling speed control valve.

idle.jpg

I take it this should be replaced or is this acceptable?

I also had a very loud hissing coming from around the turbo. I ended up removing the bumper which did not make much difference to be able examine the hoses while fitted to the car. However it allowed me to remove the lower hose and test it off the car using some more modified hole saws. Tested all the pipes individually going to the turbo but found no leaks.

I'm guessing the lower hose attached to the turbo was not secure enough or it was not on correctly. Either way after putting the hoses back on and making sure they were all secure, the hissing noise went away. So I can only think that was the source of all my problems. It's nice and dry at the moment so will take the car out for a spin and see if the fault codes return.

I also don't believe any of valves that I have replaced were the cause of the fault code. However I think changing them was the right thing to do. They have seen 110K miles and are 27 years old, they were also cheap enough and not too much damage to the wallet was done by changing them. It was also good to find and clean the flame deflector plate as that must have been creating a blockage in the system.

Fingers crossed this evening I'm back to fault free motoring, for a little while anyway.

[Tractor Dave]

There is a thread here somewhere about the idle control valve sealing. Basically, fill the end with epoxy glue.

[B5NUT]

Thanks Dave. I'll have a search later on.

Took the car our and all faults have gone. However I did find another problem.

Looks like the bulbs have failed in the external temperature display
temp.jpg

[newsh]

The ISV is not a huge leak but worth doing, as Dave says, epoxy seems to be the way.

When you get that done you want to be able to pump it up to 1.3 Bar and it holds or drops really slowly.
You can do 0.5 Bar test with the PCV reconnected to the MAF hose too which will check your breather system and oil filler cap! (you might need to hold the oil cap down but again it should only ever see vacuum).
Finally to check the Diverter Valve diaphragm, pull the actuator hose off the nipple at the front of the manifold and check it holds vacuum, or block the nipple, pressurise the system and make sure nothing comes out the vac line.

[newsh]

Thanks Dave. I'll have a search later on.

Took the car our and all faults have gone. However I did find another problem.

Looks like the bulbs have failed in the external temperature display
temp.jpg

Good news the faults have gone, does the car feel a bit more brisk?

There's always something more to do eh?

[B5NUT]

I would not say it's a massive change, but does feel like it's got a bit more power.

I know there there is always something. Still need to fix all the rattles on the car when I can be bothered. I just want to drive it. It's been off the road for the last couple of weeks while I sorted this issue out.

[B5NUT]

Had a good long run this lunch time. All codes have now gone and it's pulling really well all the way up to 7K. Thanks for the help on sorting this

[Rikki Kitto]

Kit can sort the tiny bulb out for you in the temp display it's a pain to do they are the size of a grain of rice

[newsh]

Kit can sort the tiny bulb out for you in the temp display it's a pain to do they are the size of a grain of rice

On eBay they are actually listed as “grain of rice bulbs”

[newsh]

Had a good long run this lunch time. All codes have now gone and it's pulling really well all the way up to 7K. Thanks for the help on sorting this

Always a pleasure man, I mostly try to pass on what I learnt here