[xj] Oil leak from dip stick hole?

Has anybody had problems with oil being thrown or blown out of the dip
stick hole. There is a seal on the dip stick but I note that the dip
stick hits bottom before the seal seats. A temporary fix seemed to be
to move the seal down the dip stick to make a seal. However,
periodically I find oil on the block around the hole and burning off of
the catalyic converter. How important is that seal?

Bill
'87 SIII
Pleasanton, California

The dipstick seal IS important. A few things: 1) you may have the wrong
dipstick. It should not “hit bottom” before the seal is seated. 2) If the
seal flange is loose or moveable, get a dipstick from a Jaguar 4.2 wreck. 3)
in any case, oil should not be thrown from the dipstick tube. If you have
this happening then your crankcase pressures are too high. Is your oil level
correct? (Check in the morning before setting off, NOT at a fuel stop). Your
crankcase ventilation system may well be clogged. Remove the four chrome
nuts at the front of the engine breather assembly (top front). Remove the
rubber boot. If there is white gunk inside you need to remove the screen,
the tubing, etc. and clean it all thoroughly in solvent. Finally, is your
oil clean or is it milky showing signs of coolant in the oil? If there is
coolant, then you likely have a head gasket failure. This is routine, but
unpleasant, on the SIII engine anytime after 80,000 miles. A failed gasket
can also leak collant to the outside rather than into the block, so check
the rear of the block for coolant leaks.
Gregory-----Original Message-----
From: bfoster2 bfoster2@home.com
To: xj@jag-lovers.org xj@jag-lovers.org
Date: Sunday, February 06, 2000 12:19 PM
Subject: [xj] Oil leak from dip stick hole?

Has anybody had problems with oil being thrown or blown out of the dip
stick hole. There is a seal on the dip stick but I note that the dip
stick hits bottom before the seal seats. A temporary fix seemed to be
to move the seal down the dip stick to make a seal. However,
periodically I find oil on the block around the hole and burning off of
the catalyic converter. How important is that seal?

Bill
'87 SIII
Pleasanton, California

Bill: yes, the seal is a hard rubber, quite like plastic. But the dipstick
should have 4.2 stamped on it at the bottom; at least both my 4.2 engine
dipsticks do. If it does not, then this may not be the correct one. But I do
not see how the seal flange could move. The dipstick definitely does not
touch the bottom of the sump when inserted, so yours may be too long. If so,
your oil level will not be correct, and it could be overfilled. The correct
dipstick has a crosshatch pattern on it for the “safe” level. It seems that
in the 4.2 engine, when the oil level is towards the upper limit, more oil
is used. Filled to half way up the crosshatch pattern, and the engine seems
to use no oil at all.
I have had the same experience on both engines.
Gregory-----Original Message-----
From: bfoster2 bfoster2@home.com
To: Dr Gregory Andrachuk mgb@uvvm.uvic.ca
Date: Sunday, February 06, 2000 2:08 PM
Subject: Re: [xj] Oil leak from dip stick hole?

Dr. Andrachuk:

Thank you for your thoughts. The wrong dip stick is an interesting
possibility. The crank case could be too full. I added oil to the
crank case just before this last episode of leakage.

Fortunately the oil is black with no sign of coolant. I tried running
the engine at 2000 rpm with my thumb on the dip stick hole and could
detect no pressure at all. Investigation of the surrounding block, etc.
has me convinced that oil is definetly coming from the dip stick hole.
I removed the seal and found it to be very hard, more like black plastic
than black rubber. Is that normal?

Bill
'87 SIII
Pleasanton, California

Gregory’s wrote:

If the seal flange is loose or moveable, get a dipstick from a
Jaguar 4.2 wreck.

I agree completely with Gregory’s assessment of your oil problem. However,
cleaning may go beyond merely the breather screen and flame trap (if you
have one–its a round metallic filter that sits just under the rubber boot),
if these have accumulated significant levels of crud. I recently cleaned
out the metal line that runs from the breather cap to the throttle body and
noted an appreciable build up of crud in this, too (due, no doubt, to my
leaking head gasket). This pipe is easily removed once the air cleaner is
out of the way. There is an intermediate connection on the pipe to the
charcoal canister and a hose clamp at the throttle body that must be undone
to remove the pipe.

As for the proper dip stick, note that at some point during the SIII 4.2
production, Jaguar modified the dipstick and later engines have the “full”
mark higher up on the dipstick shaft than the earlier engines–that is, the
later engines take more oil to reach the “full” mark. The difference is
something less than a quart, but you probabably should get a dipstick from a
4.2L that is the same year as yours. I do not recall why Jaguar changed
the oil level; perhaps someone else remembers why this occurred.

Regards,
Tom Golodik