Injector seals boost leak

[mcandmar]

Heres one i've not seen mentioned before, worth checking if your looking for 100% health as it only takes a few seconds.

Our S4 had developed a rough idle and makes a whistling sound under boost. Turns out the problem is the seals between injectors and intake manifold, if i pour a little water around the no4 injector its starts to stumble as it sucks it in water around the injector. No4 is really bad but i can also hear a difference on two more when pouring a little water around them, going to replace them all and see how she runs...

Mark.

[driftin jo]

Yes I've seen this before, my mates trick was two spray wd40 on them and see is the idle changed, although I don't think this is good for the seals myself as it would degrade the rubber.

[S-Express]

send me an sae and i'll send you a set of o rings

[stevieyid]

Thats interesting as i have a squeeling noise under boost. Is it quite a noticeable sound? Mine seems to happen at full boost only.

[stevieyid]

Just taken my injectors off to replace the o rings as i had a squeeling noise under boost agin yesterday. Is there a certain way to replace the o rings? How do you get the old ones off and the new ones on without damaging or stretching them?
Also the little plastic hats that are on the bottom of the injectors, 2 are cracked. Could this cause a problem?

[S2central.net]

Stevie - get those injectors refurbed & ASNU tested - search forum for recommended places to get that work done. Can be done by post...

Suggest you carefully try the water or WD40 technique on each one whilst idling.

The seals can be damaged alright and you should always renew them when refitting injectors... lube new seals with petrol helps a lot with fitment.

[stevieyid]

I have done a search and enquired about the injector refurb at the same place Al Wyn got his done. Do they renew all the o rings and the pintle caps

[S2central.net]

I can't quote for that company - but i would certainly expect that to be the case.

[s2driveruk]

all ASNU centres replace the common items including pintles, o rings (both), clean etc and flow test before and after so should be safe.

[Audi Parts Guru]

all ASNU centres replace the common items including pintles, o rings (both), clean etc and flow test before and after so should be safe.

In theory yes they should be replacing these. However I have seen some injectors that have come back from an ASNU service centre with the original pintle caps and O rings still in place.

I suppose you get what you pay for

[s2_bo]

New rings from the dealer are about £20 a set...

IIRC silicone lube is the best to use when refitting the injectors, it doesn't damage them and helps to make a good seal.

[quattro20v]

Part numbers would be great for all the stuff that needs to be changed on this. Anyone?

[s2_bo]

The 10 seals are all the same, part number is: 035 906 149 A. They are about £2 each from Audi though.

Silicone grease should be available from your local motor factors.

On a 3b engine you will also need new o rings on the banjo fittings if you chose to remove them from the fuel rail to change the injectors.

Part number is: N 013 812 8

Not sure what the deal is with ABY/ADY/ANN engines but the FPR is mounted at the rail so i dont think you have the same problem with banjo washers.

[Andreas]

The 10 seals are all the same, part number is: 035 906 149 A. They are about £2 each from Audi though.

Silicone grease should be available from your local motor factors.

On a 3b engine you will also need new o rings on the banjo fittings if you chose to remove them from the fuel rail to change the injectors.

Part number is: N 013 812 8

Not sure what the deal is with ABY/ADY/ANN engines but the FPR is mounted at the rail so i dont think you have the same problem with banjo washers.

How about the plastic hats bo?

[s2_bo]

Not sure if they are available separately? I cant find them on the family album.