SCarGo02

A weekend prior to this past weekend we (my father [who's more mechanically inclined than I] and myself) attempted to track down and fix the annoying oil leaks on my '93 90 (leaked like crazy, smelled even worse [when hot]). After degreasing the engine, replacing various gaskets (valley pan, intake (x2), valve cover (x2) and EGR valve), and the two check valves under the valley pan cover (to keep the car from ticking at start up and idle) the car seemed to still leak oil -- <b> WORSE!!!</b>

I did some more research on the AW forums and found a thread regarding a TSB on the 12V AAH engine <a href="https://forums.audiworld.com/general/msgs/7396.phtml">Clicky!</a> (Also available on the Bentley EBahn V2 CDs for 12V cars).

<b>Firstly</b> we found my valley pan cover was slightly warped, so I sanded it as per the TSB (put in another new gasket, along with some permatex):

- Remove the intake manifold to gain access to the valley pan cover, see Repair Group 15 for additional information.

- Remove the valley pan cover and gasket.

- Inspect the cover for distortion or warping. If the cover is warped

- Sand the cover until flat (on a flat surface) and verify flatness with a straight edge reference.

<b>Secondly</b> it looked as though the heads were leaking down the into the valley, then down the back side of the engine/tranny so we decided to try the fix in the TSB for the heads:

If it requires less than 40 Nm (30 ft lb) to turn any one head bolt:

- Loosen and re-torque each bolt one at a time using the following procedure.

- Tighten the bolts to 60 Nm (44 ft lb) in the sequence as shown in the illustration.

- Turn each bolt an additional half turn (180°). It is acceptable to achieve the additional movement in two 90°increments.

<center><img src="http://pictureposter.audiworld.com/42983/12v_head_bolt.jpg"></center>

This was achieved with a 25" breaker bar and a E14 socket (available at Sears and various other tool stores near the Torx tools). This seems to be a female Torx socket (although I could be wrong).

<center><img src="http://pictureposter.audiworld.com/42983/25_inch_breaker_bar.jpg"></center>

<center><img src="http://pictureposter.audiworld.com/42983/e14_socket_top.jpg"></center>

<center><img src="http://pictureposter.audiworld.com/42983/e14_socket.jpg"></center>

Sure enough after re-doing the valley pan, tightening the heads, cleaning up the engine (again) and then taking it for several drives that got it up to normal temperature (where you'd normally smell oil burning off of the cats/tranny/engine through the vents) <b>not a drop of oil has leaked from my engine in the past two days!!!</b>

So for all of you AAH 12-valvers out there, this might be worth a shot!

oddBALL

Now I just have to decipher that whole mess.

SCarGo02

...I put some in a spray bottle (full strength) and sprayed the hell out of the engine...then washed it off with a high pressure hose.

<IMG SRC="http://www.simplegreen.com/images/industrial/product/01photo.gif">

<A HREF="http://www.simplegreen.com/products/industrial/product1.html"> Clicky! </A>

BTW [by the way]: You can get it in one gallon jugs at Home Depot for about 8 dollars, it's about the same price for half the amount at Wal*Mart...

BTW2: Works as a decent wheel cleaner as well!

SCarGo02

...I don't know if that applies to the AAH/AFC (12/94 to 4/95). It supposedly doesn't apply to the AFC (5/95 and up)

oddBALL

I dont think it could hurt to try though, hmm I will see what I can do.

AlanBDahl

I have a late '95 90 Quattro with the AFC engine (built 3/95), is there a similar TSB for this engine?

MikTip

lean towards Raceware studs!(They dont stretch) ;O)<ul><li><a href="http://www.raceware-fasteners.com/">http://www.raceware-fasteners.com/</a</li></ul>

SCarGo02

...valve covers, cam cover (back of the right cylinder bank), valley pan, etc. This was on 95-97 AFCs. Even though there's not a TSB they're still known to leak. If you search the C4 (100/A6 forum) and the A4 (B5) forum they both have some threads regarding leaks on the 12V engine...

Hope this helps...

SCarGo02

The cam cover (#32 in the diagram - P/N: 078-103-113-E) was replaced with a new design, which doesn't utilize parts 35, 34, 33 and 31. Oil was leaking from the old style cover; the new one has no leaks as of yet.

<IMG SRC="http://pictureposter.audiworld.com/42983/etka_cam_cover_diagram.jpg">

Also, when sanding the valley cover, we also sanded the mating surface on the engine block. It was quite rough from machining marks. Both surfaces were sanded with 320 grit sandpaper, then 400 grit.

Just a few afterthoughts I forgot to mention...

Reggie

to do and drink beer while I do it.