A8 / S8 (D3 Platform) Discussion Discussion forum for the D3 Audi A8 produced from 2003-2010 and Audi S8 produced from 2006-2010

10' 4.2 V8 Rattle

 
Old 07-09-2019, 12:46 PM
  #1  
AudiWorld Member
Thread Starter
 
Join Date: Mar 2019
Location: Ontario, Canada
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Default 10' 4.2 V8 Rattle

I have been chasing down a fairly consistent engine ticking/tapping. The engine is always silent upon startup for the first 5-10 seconds whether the engine is hot or stone cold. A little background, I have tried many oil viscosities from thinner to thicker with no change at all. I have since replaced the oil with 502 spec 5W40 that's called for in the manual. I've replaced the valley pan gasket, anti-drainback valve and oil jet, air filter.

If I remove the oil filler cap the ticking disappears... I used a stethoscope and I was able to isolate the noise to the passengers side valve cover. If I position the scope and then pull the oil cap I can hear the tick
dissapear and reappear when the cap is replaced. I can only assume that the noise is valvetrain related? If I pull the hose that leads from the drivers valve cover to the oil separator there is a good amount of pull (vacuum) from the separator and if I plug the hole in the valve cover it builds substantial positive pressure? Does anyone know if this condition is normal?
2010A8Lsport is offline  
Old 07-09-2019, 01:10 PM
  #2  
AudiWorld Member
Thread Starter
 
Join Date: Mar 2019
Location: Ontario, Canada
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Default

Does that sound like the oil separator is functioning properly? I've already had it off and replaced the diaphragm with a new one from RKX.
2010A8Lsport is offline  
Old 07-10-2019, 04:59 PM
  #3  
AudiWorld Member
Thread Starter
 
Join Date: Mar 2019
Location: Ontario, Canada
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Default

Anybody have any idea???
2010A8Lsport is offline  
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
huffy15
A6 / S6 (C6 Platform) Discussion
5
06-07-2014 08:56 AM
tommo2
A6 / S6 (C5 Platform) Discussion
10
02-18-2013 07:41 AM
HIstateS8
A8 / S8 (D2 Platform) Discussion
8
07-05-2009 08:14 PM
//Swordfish
Audi Original "S" Cars
6
10-24-2007 08:27 AM
Boy Wonder
Audi 100 / A6 (C4 Platform)
4
12-24-2002 04:44 PM


Thread Tools
Search this Thread
Quick Reply: 10' 4.2 V8 Rattle


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: