My S2 coupe bit of a rebuild and repair thread.

[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

[Tractor Dave]

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

[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.

[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?

[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]

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

[Tractor Dave]

Nice work

[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.

[B5NUT]

I finally found the part number of the "Flame Deflector Plate" as Audi call it and has part number 035103477A They are obsolete but can be purchased from VW Classic and Tradition. Will just be cleaning my one up and putting it back in.

[sidrick]

I remember this flame trap, and it being unavailable about 10 years ago. From what I read they're serviceable (cleanable) and fairly universal around older VAGs. Pretty sure you can find similar on old VW buses still available.

[B5NUT]

So had a bit of fun this evening (If you can all it that). Removed the pressure regulating valve in the crank breather system.

It was caked with oily crud inside.
breath.jpg

Then I found this.
it.jpg

I found it inside this pipe
pipe.jpg
I cleaned it up and it now looks like this
it2.jpg

I can see the part in the etka diagram but it's no longer list as a valid part. Did Audi do away with this as a bad idea? It must have been causing a blockage as it was full of crud!

The pressure regulating valve does not appear to do anything. Should the valve be opened or closed all the time and does it only close or open once the pressure is too high?

[sidrick]

Great work!

[Tractor Dave]

http://www.s2forum.com/forum/showthread.php?t=63974&highlight=boost+leak+testing

[B5NUT]

So I've replace the fuel pressure regulator and the boost pressure control valve, and other than starting the car to make sure it's working with the new parts fitted. I've not driven it as the weather has not been the best.

Before I take it out for a drive I want to complete a boost pressure test. I should have done this when kit loaned me his testing kit but as the car was working fine back then with no error codes I figured in the end there was no point. I guess when I pushed it on or near the limiter that has caused the failure somewhere. I think!

So I've started to make my own boost pressure kit. Got one of these for £9. It's a cheap 79mm hole saw.
pressure_tester.jpg

After cutting it down removing all the paint and welding up all the holes. it came out like this. The hole in the centre was a perfect fit for a normal tyre valve.
pressure_tester1.jpg

It still needs a coat of paint but it should do the job.

To plug the boost pressure control valve, I've cut off the top of one of the old S2 front shock absorbers. It's was a perfect fit.
pressure_tester2.jpg

So question, is there anywhere else that need a plug making before I perform the pressure test?

[B5NUT]

Thanks for the information. I'll look to get the end cap and make the other parts.

Cleared the fault codes, and took the car for a drive out. Got it to 6K RPM and no problems.

However this fault code came back and It's slightly different to the one above
00561 - Mixture Adaptation
13-10 - Adaptation Limit (Mul) Not Reached - Intermittent

The car drove fine and never noticed any loss of power.

Also after reading this thread https://www.s2forum.com/forum/techni...s-running-rich I've also ordered a new FPR and PCV valve.