Friday, December 20, 2013

Audi A8 Crankcase breather Hose Improvised Replacement

I bought a car at the Auto Auction on Thursday.  It's a 1999 Audi A8.  It's a lot of car, but it spoke to me and I had to have it.  Unfortunately it has a few issues.

I've got a number of trouble codes that point to a vacuum leak.  I pulled off the engine covers and started poking around.  I found that the crankcase breather hose between the cylinder heads has taken on the consistency and structural integrity of an overcooked spaghetti noodle.
The Audi Part number is [URL="http://www.jimellisaudiparts.com/products/Vent-hose/5441626/077103221E.html"]077-103-221-E[/URL].  The local dealer price is $180.00 and has to be shipped in.  Even worse, it's the weekend before Christmas, so the correct replacement part is at least 7 days away.  I'd like to fix it before then. 


I've discovered that Auto-Zone Heater Hose Part number 80416 "Dayco/Hose (Lower)" can be trimmed to an acceptable fit for replacement.  It costs $10.99.  I was originally concerned that the hose would collapse under vacuum, but in initial testing that has not been an issue.  If it becomes a problem I will insert a length of 1/2" ID Convoluted Tubing (the stuff you use to organize wires into neat bundles) in the long section.

To install it:
  • Remove the engine covers over the valve covers with 4 5mm cap head allen screws.
  • Remove the 4 cap head allen screws for the center engine cover.
  • Remove the two worm clamps, one near the oil filler cap, one on the passenger cylinder head. 
  • Pull the hose off.  If it's rotted like mine it will come off in pieces.
  • Trim ~2 inches off the short end of the AutoZone part.
  • Test fit it on the oil filler cap end.
  • Test and Trim the  appropriate length from the passenger cylinder head end of the hose.
  • Install the hose with new worm clamps  Note: These are a -tight- fit.  I could not use the OE clamps and had to use flat clamps from AutoZone.  I had to push them into place with a screwdriver.
  • Tighten up the hose clamps.
  • Replace the engine covers.

Here is a terrible picture of the completed installation.





I hope this helps someone else.

2 comments:

Anonymous said...

Nice!I have 1999 audi a8 quattro also. I took off the covers last night to change a few ignition packs and found my vent hose to be disintegrating and with a large hole in it. I will try your version of replacement. Did you notice anything different after you changed it? my email is prokster@hotmail.com

Elizabeth Greene said...

Yes, after changing it the engine went from 12 trouble codes (including misfires on every cylinder and a system running too lean error) to 1.

I'm happy with the repair on the front hose, it works great. The rear two hoses don't really fit right, and I would prefer to have the correct parts for them. The cheapest I was able to find them was around $85 each. I'm hesitant to spend that unless forced.