EM TuningSky Insurance
Results 1 to 9 of 9
  1. #1
    3rd Gear

    Status
    Offline
    Join Date
    Jul 2010
    Posts
    561

    Excessive vacuum in crank case?

    I've been getting awful MPG recently and have noticed that if I remove my oil filter cap whilst idling the cap is hard to remove, once I get it off the engine is sucking air in via the oil filter cap and the revs rise.

    Is this normal? I think I may have a knackered PCV valve. Is it a DIY replacement job?

  2. # ADS
    ADS
    Join Date
    Always
    Posts
    Many
     
  3. #2
    3rd Gear

    Status
    Offline
    Join Date
    Jul 2010
    Posts
    561
    Anyone know if it's normal for the 2.0T to suck air through the dipstick and oil cap at idle?

  4. #3
    OVRA3's Avatar
    5th Gear

    Status
    Offline
    Join Date
    Jan 2012
    Location
    Norwich
    Posts
    1,071
    If I take mine off or pull the dip stick I the car runns rough and tries to stall... Is that what you mean?
    A3 Sportback 2.0 TFSI S-Line Quattro Stage 1 Tune it up - Lowestoft Custom Remap- 6187 RPM developing 260 bhp 279lbs ft Akoya Silver, Roof rails, Black heated Vienna Leather, Bose upgrade, Bluetooth

  5. #4
    MrLapou's Avatar
    5th Gear

    Status
    Offline
    Join Date
    Jan 2004
    Location
    Lincoln
    Posts
    1,165
    sounds normal to me with filler cap off.
    Last edited by MrLapou; 30th November 2012 at 18:59.

  6. #5
    3rd Gear

    Status
    Offline
    Join Date
    Jul 2010
    Posts
    561
    Quote Originally Posted by MrLapou View Post
    sounds normal to me...
    When I take the oil cap or dipstick out it starts sucking loads of air in and the revs rise. It's meant to run rough normally.

  7. #6
    OVRA3's Avatar
    5th Gear

    Status
    Offline
    Join Date
    Jan 2012
    Location
    Norwich
    Posts
    1,071
    Quote Originally Posted by Minstadave View Post
    When I take the oil cap or dipstick out it starts sucking loads of air in and the revs rise. It's meant to run rough normally.
    Dont think so mate, when you take off the cap it should shudder and struggle... Sure someone who knows more will be along soon
    A3 Sportback 2.0 TFSI S-Line Quattro Stage 1 Tune it up - Lowestoft Custom Remap- 6187 RPM developing 260 bhp 279lbs ft Akoya Silver, Roof rails, Black heated Vienna Leather, Bose upgrade, Bluetooth

  8. #7
    RobinA3's Avatar
    6th Gear

    Status
    Offline
    Join Date
    Aug 2005
    Location
    Cheshire
    Posts
    1,758
    Yes there should be a vacuum inside the engine. The crankcase pressure should always be negative so when you remove the filler cap or dipstick when the engine running it will run like a sack of **** as unmetered air (air which is not measured by the airflow meter) is entering the engine.

  9. #8
    wuta3's Avatar
    4th Gear

    Status
    Offline
    Join Date
    Jul 2012
    Location
    Manchester/Sheffield
    Posts
    849
    Quote Originally Posted by Minstadave View Post
    I've been getting awful MPG recently and have noticed that if I remove my oil filter cap whilst idling the cap is hard to remove, once I get it off the engine is sucking air in via the oil filter cap and the revs rise.

    Is this normal? I think I may have a knackered PCV valve. Is it a DIY replacement job?
    I had a rough idle, with reeealllyyy hard to remove oil cap etc and it was the PCV. It's an easy job on your drive. I gave the tubes a good clean too because they were caked in crap.
    ​​Programmer/Web Developer, Headphone/Amp Geek
    06 SLine Special Edition Phantom Black 2.0T FSI Quattro A3
    Done: P-Flo, RevD, Sachs Organic, Milltek TBE + Res + Sports cat
    Wanted/Next:Intercooler, HPFP, Remap

  10. #9
    Reverse Gear

    Status
    Offline
    Join Date
    Dec 2012
    Posts
    13
    Yes you require a new PCV valve the oil filler cap should not be that difficult to remove when engine on idle 5 min job

 

 

Similar Threads

  1. Crank case breather
    By Boombastik in forum A3/S3 Forum (8L Chassis)
    Replies: 4
    Last Post: 13th November 2012, 18:47
  2. crank case breather
    By vr6gordy in forum A4/A4 cabriolet/S4 forum(B6 chassis)
    Replies: 6
    Last Post: 30th December 2010, 19:22
  3. 1.9 TDI crank case pressure (youtube clip)
    By johnmccracken in forum A4/A4 cabriolet/S4 forum(B6 chassis)
    Replies: 2
    Last Post: 8th August 2009, 14:39
  4. normal crank case pressure
    By johnmccracken in forum A4/A4 cabriolet/S4 forum(B6 chassis)
    Replies: 3
    Last Post: 4th August 2009, 01:15
  5. Crank case oil seal
    By aldi in forum A3/S3 Forum (8L Chassis)
    Replies: 0
    Last Post: 4th July 2006, 21:46

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Single Sign On provided by vBSSO

Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

Content Relevant URLs by vBSEO