XJ6 & XJ12 Series I, II & III 1968-1992

Mayo Under The Cam Cover

Thread Tools
 
Search this Thread
 
  #1  
Old 05-18-2013, 05:32 PM
Woznaldo's Avatar
Senior Member
Thread Starter
Join Date: Jul 2012
Location: Canberra, Australia
Posts: 287
Received 50 Likes on 35 Posts
Default Mayo Under The Cam Cover

While pulling off my Cam Cover on my S1 to fix a leak, I also noticed that I had Tappet Sleeve movement and decided to fit the Stake Down Kit.

https://www.jaguarforums.com/forum/x...t-68777/page3/

While doing this I was going to remove the Camshaft so pulled off the breather from the front of the engine to release the Cam Chain tension. When I puled the breather off, it was full of sludge and water! There was also some signs of water in the oil system under the Cam Cover (the mayo).

I have noticed that there is some brown sludge under the cap of the Inlet Manifold Header Tank. Could all of this be Head Gasket related or should I be looking for a crack in the Head/Block?

I think, ultimately, the Engine needs a full rebuild as there are a number of small issues that need addressing......
 
  #2  
Old 05-18-2013, 06:38 PM
icsamerica's Avatar
Veteran Member
Join Date: Apr 2012
Location: New York City
Posts: 2,205
Received 1,364 Likes on 793 Posts
Default Hold the Mayo

How much Mayo? A small amount, about 1/2 tea spoon, collecting on the bottom of the fill cap or some other area could be normal. Larger amounts clearly indicate water in your oil and a major problem. Does your jag run cold? Cool engine temps dont allow the engine to get hot enough to evaporate moisture then enters from the ambiant air as part of the PCV system. Modern oils can absorb a considerable about of water before they display mayo or foam. Do a rundown test. Take a pice of carboard and set it upright at a steep incline. Put some fresh oil at the top and watch it run down the card board. It should move fairly slow. Next take some engine oil from the crankcase and do the same test at a similar temp. If the oil absorbs into the cardboard like water would or runs down the cardboard fast them you have contaminated oil. If you've run it like this for awhile then your engine is wiped out becasue oil contaminated with antifreeze has very little lubricity.
 
  #3  
Old 05-18-2013, 07:54 PM
Woznaldo's Avatar
Senior Member
Thread Starter
Join Date: Jul 2012
Location: Canberra, Australia
Posts: 287
Received 50 Likes on 35 Posts
Default

The mayo under the Cam Cover is a light milky film. The mayo in the Tensioner Cover was quite a lot, like a large tablespoon.

I'll try the run down test.
 
  #4  
Old 05-19-2013, 02:59 AM
Join Date: Feb 2010
Location: Adelaide Stralia
Posts: 27,606
Received 10,503 Likes on 6,935 Posts
Default

I agree with the suggestions so far.

That much "mayo" in a S1 that has been running a bit hit and miss for a while, is what I would sort of expect. Also, Sydney has some serious cold mornings lately, and short running creates "mayo".

Old gungy oil will make its own "mayo".

That filter in the front is always a trap for that stuff, and I would be looking at the other end of that breather pipe/hose, and ensure it is actually clean and not blocked with that "mayo" hence creating the perfect atmosphere for more "mayo".

A S3 I had here once had that pipe seriously blocked, and "mayo" to burn was everywhere. Once unblocked, new oil and filter, new proper temp thermostat, all sweet. The engine was running waaaaay too cold, so among other issues the "mayo" was heavy.

Not discounting a head gasket etc, but I really do seriously doubt it, based on the posts so far on this car.

Is it running too cold???.
 

Last edited by Grant Francis; 05-19-2013 at 03:02 AM.
  #5  
Old 05-19-2013, 09:08 AM
JagCad's Avatar
Veteran Member
Join Date: Jul 2012
Location: Walnut Creek, California
Posts: 6,796
Received 2,399 Likes on 1,880 Posts
Default

When I was a kid, I traded my .22 HiStandard, Luger-like pistol for a decrepit 34 Ford
V8 coupe. Rodders of today would salivate over it as raw material. it was my "second" car. Desert raced it a couple of times on a 1/4 mile in junk class. it was a better racer than I a race driver!! Trouble was it only ran on 8 when the throttle was about half or better open. Poor valves in some bores!! And, worse, it had a crack or two in the block!!

Mayo was constantly being generated. No biggie, I worked in a service station. So, it got frequent oil changes from the used oil barrel. Just water as a coolant, so no glycol contamination. As I tired of it, I sold it to a young guy with new wife and kid that had returned from WWII service as a marine. He needed a car cheap. he got it. With all it's warts, it was actually quite dependable!!!

In this case, I suggest definitive action. Clean the crankcase vent system thoroughly. Change the oil and filter and observe for further mayo production. Check the coolant for hydrocarbon contamination. Do a compression test. Beware of low readings in adjacent bores.

A reliable block sealer might coax a few more miles out of it if it has a cylinder head leak. NOT, the B.... stuff.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Bcrary3
XJ XJ8 / XJR ( X308 )
35
02-21-2023 04:29 AM
Davidvdm
X-Type ( X400 )
11
10-07-2015 03:18 PM
Dickie_L_J_O
XJ XJ8 / XJR ( X308 )
8
09-13-2015 07:44 AM
jagent
XJ6 & XJ12 Series I, II & III
8
09-12-2015 09:10 AM
jaggermang
XJ XJ8 / XJR ( X308 )
9
09-08-2015 07:07 PM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


Quick Reply: Mayo Under The Cam Cover



All times are GMT -5. The time now is 01:33 AM.