I finally got down to a proper test and the results were not good
left bank 1,210,2 208,3 212,4 60,5 145,6 205,the rigt bank was a
solid 210 +/- 5 I did add oil to the #4 and the compression came up
to 85
What do you guys think bad rings or piston or head gasket I hate
the thought of pulling the engine unless I can find some help on
the north west coast
Thanks Bob–
yoeman
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// please trim quoted text to context only
In reply to a message from yoeman sent Sat 7 Feb 2009:
Bob:
Leaky exyaust valve.
leaky intake valve.
Leaking compression rings.
Leaking head gasket.
With #4 at TDC apply compressed air to #4. Listen at exhaust. If
you hear escaping iar ther, the conclusion is clear. Same as to
intake manifold for that bank. Listen at crankc as the filler.
A likely result is leakage at two of the three or even all three.
Serious leaking into the crankcase means, pull and dissamble the
engine.
Just my ideas after fixing and abusing all manner of engines except
a Jaguar V12.
I hope it’s ‘‘just’’ a leaky valve or two as that means pull a head
or two and do a good valve job. That should get you a nice running
engine.
Carl–
The original message included these comments:
I finally got down to a proper test and the results were not good
left bank 1,210,2 208,3 212,4 60,5 145,6 205,the rigt bank was a
solid 210 +/- 5 I did add oil to the #4 and the compression came up
to 85
What do you guys think bad rings or piston or head gasket I hate
the thought of pulling the engine unless I can find some help on
the north west coast
–
Carl Hutchins 1983 Jaguar XJ6 with LT1 and 1994 Jeep Grand
Walnut Creek, California, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
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In reply to a message from cadjag sent Sat 7 Feb 2009:
how bad is it to pull the heads Im thinking of taking a shot at it
but dont want to end up with a box of parts–
The original message included these comments:
- Leaky exyaust valve.
–
yoeman
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Hi Bob,
I’m not sure what to think of those results. A burned exhaust valve
would NOT be expected to allow as high as 80 PSIG wet compression, let
alone 145 dry. I can’t account for why two adjacent cylinders would
have bad rings or piston damage. Both low compression cylinders are
adjacent (4B & 5B), suggesting a blown head gasket at the sealing rings
between those two cylinders, BUT one would expect essentially equal
compression on the two cylinders if that were the case, and you would
also be likely to hear a “poppa - poppa” noise from compression/power
stroke blowing between cylinders. ALL A bank cylinders are OK, so if
what is described below doesn’t fix the problem, pulling the B bank
head probably would.
I assume you don’t have any clacking sound, indicative of dropped valve
seat? How is your idle speed, and do you have an intake manifold
gasket leak? How long have you had the car, and if it has any known
history of overheating, when did that occur? Have you regularly taken
it to 6K RPM to blow out the carbon, or do you drive almost exclusively
short distance & low speed & RPM trips?
If the latter, you may have carbon-fouled intakes on 4B & 5B which may
be improved by using injector/fuel system cleaner and doing some
Italian tuneups (1st gear forays to 6k RPM). I would certainly try two
applications of injector cleaner and daily Italian tuneups for a week
or two, and then retest (wet --squirt of oil in each cylinder before
testing that cylinder). With luck, your problem is carbon-fouled
intake valves, which can be significantly improved as described above,
without pulling the head and cleaning/lapping the valves.
George Balthrop, Clifton, VA USA
85 & 89 XJ-S Coupes; 89 XJ40 VDP-----Original Message-----
From: yoeman rcrich@telus.net
I finally got down to a proper test and the results were not good
left bank 1,210,2 208,3 212,4 60,5 145,6 205,the rigt bank was a
solid 210 +/- 5 I did add oil to the #4 and the compression came up
to 85
What do you guys think bad rings or piston or head gasket I hate
the thought of pulling the engine unless I can find some help on
the north west coast
Thanks Bob
// please trim quoted text to context only
In reply to a message from gbalthropxjs@aol.com sent Sat 7 Feb 2009:
No clacking so seat should be ok,car runs but as per posts very
high pollution levels The low cyl is the only one I added oil to
and it came up to 85 psi from 60 the other cyl is 145 dry The car
does seem to produce above average exhaust moisture on starts after
its been sitting but then clears so I am suspect of a small coolant
leak into the cly But I didnt find any suspect plugs.Idle speed is
ok but aav idle adjuster nut does not really changfe speed much
Maybe 300 rpm Is there a post on head removal and do I need special
tools?
thanks Bob–
The original message included these comments:
I’m not sure what to think of those results. A burned exhaust valve
–
yoeman
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