Welcome to 911UK
The only place for Porsche, 911uk is the definitive enthusiast and resource site for the Porsche 911.
Registration is fast, simple and absolutely free, so join up today for full access to the site and benefit from latest member offers.

Porsche Classifieds
Sell Your Porsche on 911uk
Create a Free Classified Advert
Search Ads
Classified Adverts FAQ
Trade Classified Information
Buyer & Seller Fraud Protection
Consumer Rights Act
Pre Purchase Inspection (PPI)
Porsche Car Sourcing
Porsche Cars Wanted
Official Porsche Centre Reviews
Porsche 911
992 : 2019- 0
991 : 2011- 24
997 : 2004- 67
996 : 1997-2005 34
993 : 1993-1998 4
964 : 1989-1993 2
Carrera 3.2 : 1983-1989 2
Carrera SC : 1977-1983 2
930 Turbo : 1975-1989 1
Early 911 : 1964-1977 1
Porsche Other Models
Classic : 1950-1965 0
Boxster : 1997- 30
Cayman : 2005- 21
Cayenne : 2003- 6
Macan : 2014- 6
Panamera : 2009- 0
912-914-924-928-944-968 1
959 - CarreraGT - RaceCar 0
Car Parts For Sale & Wanted
Other Items For Sale & Wanted
Wheels Tyres For Sale & Wanted
Number Plates For Sale Wanted

Porsche Services
Porsche Body Shop Repair
Paint Protection & Wrapping
Porsche Classic Insurance
Porsche Classic Parts
Porsche Classic Restoration
Porsche Design Collection
Porsche Engine Gearbox Rebuild
Porsche Heritage & History
Porsche News
Porsche Picture Gallery
Win a New Porsche 911

Porsche Parts
Body Parts, Body Styling
Brakes, Clearance
Electrical, Exhausts
Engine Cooling, Engine Electrical
Engine Rebuild, Heating Cooling
Interior Incar, Lighting
Rubber Seals, Service Parts
Steering, Suspension
Transmission, Workshop Tools
Early 911, 911 - 930, 928 - 968
964 - 993, 996 - 997, Boxster
Cayman, Cayenne, Panamera

Porsche Model Range
911 [992] 2018-Current
Porsche 911 [992]
911 [991] 2011-2019
Porsche 911 [991]
911 [997] 2004-2012
Porsche 911 [997]
911 [GT] GT1-GT2-GT3
Porsche 911 [GT]
911 [996] 1997-2005
Porsche 911 [996]
911 [993] 1993-1998
Porsche 911 [993]
911 [RS] RS-RSR
Porsche 911 [RS]
911 [964] 1989-1993
Porsche 911 [964]
911 3.2 1983-1989
Porsche 911 3.2 Carrera
911 SC 1977-1983
Porsche 911 SC
911 [Early] 1964-1977
Porsche 911 [Early]
Boxster & Cayman
Porsche Boxster & Cayman
Cayenne & Panamera
Porsche Cayenne & Panamera

911uk Site Partners

Post new topic   Reply to topic
Author Message

Joined: 08 Nov 2008
Posts: 30174
Location: Hertfordshire and Hampshire

PostPosted: Sun Feb 24, 2013 5:33 pm    Post subject: Oil cap gunk, mayo, yellow/white residue and Head Gaskets Reply with quote

The water-cooled 911 and Boxster/Cayman all have remote oil filler necks.

Most cars have the oil access directly into the top of the engine (assuming vertical, not boxer), generally via the rocker cover.

Because of this outlying filler tube and cap, during cold weather and especially after short journeys (that don't get to warm up these extremities) a white/creamy yellow gooey condensate emulsion of oil vapour and combustion water vapour can build up right at the end of the extended and horizontally lying oil filler neck and under the filler cap.

The remedy is to simply wipe off and drive faster and longer!

Some examples:

It is not harmful, and in normal circumstances the oil and water vapour would have been recycled into the block and sump. It is only the cul-de-sac of the oil filler neck and cold weather condensation that causes it.

In theory the gooey emulsion could too be recycled by the engine, if only you could get it back in! (it doesn't flow).

But it is easier just to wipe off.

Kitchen paper or similar (disposable J-cloth etc) can be used to remove the residue (the "mayo" shouldn't extend further than a few inches down the pipe, if it does wrap paper round a tooth brush or coat hanger etc - DON'T LOSE IT!). Do not use any old dirty rag either - you don't want any dirt/grit particles to enter the sump.

Head Gasket Failure
Having said that, this mayo can still be caused by a headgasket failure.

Firstly check the dip-stick (on vehicles without a dip-stick the sump may be carefuily dipped via the oil filler neck using a flexible plastic pipe etc) for water/emulsion contamination in the sump and also check for cross-contamination of the coolant in the header tank.

Make sure there is no water loss and the coolant is nice and clear - if the coolant has oil in it or you are mysteriously losing coolant (burnt off through cylinders as white smoke) then you have a headgasket failure.

The header tank will exhibit a dirty or oily composition - oil may be recognised by a rainbow skin on the surface. An HC (hydrocarbon) "sniff" test may be made by any competent garage to check for exhaust based contamination in the coolant.

If no water/emulsion in sump and no oil in coolant, and no coolant loss, then just cold weather/short run "mayo".

Wipe off and drive faster and longer!
View user's profile Send private message

Joined: 19 Aug 2012
Posts: 18
Location: Sutton Coldfield, W.Mid

PostPosted: Fri May 24, 2013 1:38 pm    Post subject: Reply with quote

That's a big relief. GT4. Thanks. Time to hit the revs!!
View user's profile Send private message

Joined: 10 Aug 2018
Posts: 20
Location: Cambridgeshire

PostPosted: Tue Jan 22, 2019 2:13 pm    Post subject: Reply with quote

A reply to an old thread to simply say this forum is great!

Topped up the oil at the weekend, the 996 is a daily driver with a relatively short (12 mile) drive each way. Opened up the oil filler cap and to say I was concerned was an understatement!!! Sad

A quick search on here revealed this thread and I was a much more pleasant person to be around 10 minutes later.

So to everyone on here that puts the effort into these useful threads and commenting on the questions from newbies - a big thank you, you know who you are worship worship
View user's profile Send private message
Le Mans
Le Mans

Joined: 06 Mar 2014
Posts: 17134
Location: The Ribble Valley, Lancashire

2000 Porsche 996 Carrera 4

PostPosted: Tue Jan 22, 2019 2:30 pm    Post subject: Reply with quote

That's another email landed in GT4's inbox Grin
2000 Manual 996 C4 Arctic Silver Convertible

View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic   All times are GMT - 12 Hours
Page 1 of 1

Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum
You cannot post calendar events in this forum