Audi TT Forum banner
1 - 20 of 44 Posts

·
Registered
Joined
·
5,176 Posts
Discussion Starter · #1 ·
Judging by this post viewtopic.php?f=2&t=166238 it seems there's a whole bunch of people with leaking/weeping injector seals who have all been very naughty indeed and ignored the best advice to have them replaced. My excuse was a lack of the exact knowledge to get in there and have a go, a lack of the right facilities at my home to do it anyway and lack of time to investigate - then winter happened.

Anyway I've done the deed now and this is a rough guide that would have helped loads had it existed before I started - so now you have no excuse!

You will need:
8x new injector seals (4 for the bottom plus 4 for the top), part no. 035-906-149A, £3.14 each inc. VAT - seems extraneous to me so you might do better going to GSF or another motor factor
Some oil - spare engine oil or 3-in-1 will do
WD40 + Meths or other degreaser (depends how thorough you want to be)
Kitchen roll / rags
A powerful vacuum cleaner with attachment for getting in to small spaces
5mm allen key with long/deep attachment or normal 5mm allen key + adjustable spanner
Assortment of screwdrivers
Wire brush / old toothbrush
A lamp

In the end I chose to just do the lower set, but having a few extra O rings is handy in case you drop any into the engine... :oops:

First you need to remove the engine covers, then you will see the fuel injector rail just in front of the engine block - it's a 15" or so long section of metal with a plastic cable harness attached to it and a round fitment on the righthand end (fuel regulator).
Unclip the small hose from the right hand end of the rail, and free off the cable harness. This is held on by a series of plastic clips, the top ones are easy but the bottom ones are a bit harder to get at. You can see them here, taken from the back of the rail. :

It's all a bit stiff and fiddly but once it's off / loose you will be able to access a pair of 5mm allen bolts underneath. You can just see the lefthand one by injector #1 in this pic. This is where you need the allen key with a long attachment, or failing that you can use an adjustable spanner on a normal 5mm allen key - this is what I did. They're weren't very tight.
Here's a pic of the cable harness freed off to access the bolts:

Careful removing the bolts, you don't want to drop them into the engine bay. Now you can give the rail a little tug and the injectors should pop out of the inlet manifold.

You need to be really careful around this area now as you don't want any foreign objects falling into the holes. I blocked them up with some kitchen roll and had a good go round the whole area with the vacuum. I used the wire brush to loosen off all the crud that was caked round the inlets, and finally WD40 and meths to clean up the leaked oil and general residue.
All of the inlets were pretty grubby and No.1 which had the most obvious seepage was filthy:


Told you! It really needed doing.
If you want more access, you can remove the metal spring clips holding the cables onto the injectors (see pic above) and lift the cables away, this lets you fully detach the cable harness from the rail. With the whole area cleaned up you can now prise the old lower seals off the injectors - a small screwdriver helps get it started.

The new ones just slip straight on, you can use a bit of oil as lube if you need to. It's best not to use silicone oil as the silicone residues can carry through the engine and interfere with the lambda sensor, thanks to John-H for some timely advice here.
If you want to replace the upper set of seals as well, you'll need to remove the injectors from the fuel rail. They're held in place by a square U-shaped metal clip and just pull out with the clip removed. Be warned - fuel will leak out so make sure you have removed all sources of ignition and stopped fuel supply to the rail before going this far. I decided not to replace the upper seals as (a) I didn't want to risk a major fuel leak and (b) there was no evidence of leak from these seals. If I were to do this I'd remove the fuel line from the rail and stopper it up before starting the job - but this is the limit of my knowledge so you'll have to seek further advice.
With the seals replaced and everything cleaned up, re-fitting is simply the reverse of removal.
Job done:

Now you can go for a short test drive and have a well-earned beer.
In total it took about 2.5 hours, mainly because I wasn't sure exactly what to do and I'm pretty fussy about cleaning stuff as I go.
 

·
Registered
Joined
·
5,176 Posts
Discussion Starter · #4 ·
Cheers and yes, No1 was really bad. I'm not sure if there isn't another problem there, one to watch.
 

·
Registered
Joined
·
7,709 Posts
Bikerz said:
No1. Looks REALLY BAD!!!! :eek:
Bad... How the hell you can ignore that one !!! it's not leaking or weeping... i'm surpirsed it's not just bee shooting out onto the underside of the bonnet... looks terrible :eek:

Very good write up though... i'd be worried about knocking the crap into the engine... and i do hope your joking about the o rings into the engine... surly thats going to be a a molton block of rubber until it disintergrates completely...
 

·
Registered
Joined
·
5,176 Posts
Discussion Starter · #8 ·
tony_rigby_uk said:
Bikerz said:
No1. Looks REALLY BAD!!!! :eek:
Bad... How the hell you can ignore that one !!! it's not leaking or weeping... i'm surpirsed it's not just bee shooting out onto the underside of the bonnet... looks terrible :eek:

Very good write up though... i'd be worried about knocking the crap into the engine... and i do hope your joking about the o rings into the engine... surly thats going to be a a molton block of rubber until it disintergrates completely...
No, it just disappeared down a gap, probably find it on the undertray when I do the oil change in a couple of months. The trick with the crap not going into the engine is to get your sister/mrs/mate to stand there holding the vacuum while you have a good scrub with a wire brush. Bit like going to the dentist...

Cheers for the comments

:D
 

·
Registered
Joined
·
130 Posts
Was a bit hesitant about removing them from the fuel rail too but turned out to be pretty easy!

If I was to do it again though I'd probably replace the metal clips (035 906 037) as mine are getting a bit corroded...
 

·
Registered
Joined
·
4,917 Posts
I've just changed mine both top and bottom seals. Thanks for the guide it was very useful. I took out the fuel pump fuse (No 28) and let the engine crank over for about 10 seconds. When I pulled the injectors from the rail to change the top seals only a small amount of fuel come out and was easily soaked up by a piece of rag.

Very easy job to do and all in only took about an hour and that was completely removing the injectors and cleaning them up :p

Also thanks Jim for the set of seals :wink:
 

·
Registered
Joined
·
210 Posts
Bump

Another thanks to Jim for the seals, all done top & bottom in about an hour, nice easy job only had minor leak on 3, but worth doing all of them on a high mileage 9 year old.

Right off for a burn
 

·
Registered
Joined
·
1 Posts
Great step by step guide.

One question though, you mention cleaning the surround area (inlet manifold) with meths/WD40.

What about the body of the injector itself? Did you also use meths/WD40 on these parts?




I'm going to be tackling this tomorrow.
 

·
Registered
Joined
·
7,709 Posts
usually just a visual is the first tell tale sign, a weeping around where the injectors go into the inlet manifold, you may find this as a oily brown, with losts of dirt on it, dirt tends to stick to the wet areas and make a nice sludge...depends on how long they've weeped for..
 
1 - 20 of 44 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top