Well I am new here, first post. This place is a wealth of
information and I hope to bring my own experience to the table as
well as find more info. I have had this car for a few years now and
have done lots of work to it. New shocks, struts, brakes (including
the ABS pump), new steering rack, tie rod ends, control arm
bushings, wheel bearings,fixed fuel tank leak, and various other
fixes and preventative maintenence.
Well that was my short intro now my current issue…
My car was running fine but I had intermitent power issues that
were mostly resolved with the replacement of the TPS, coolant temp
sensor, and O2 sensor. I still get some funny power issues when it
is very cold ~32 degrees F. I had a lean running contion due to the
One day I was comming up a very steep hill on the highway and all
of a sudden I felt a fairly severe loss of power. It was work to
keep it at 75 mph. At home I noticed it idles very rough,
especially when in gear–the car would shudder.
Removal of each spark plug wire revealed that the number 5 cylinder
was not firing well at all. The engine rpm would hardly change for
that cylinder. I figured I had a burned valve due to weakness
caused by previous lean condition and the heat caused from climbing
I did a compression test and found interesting results. All
cylinders had great compression 140-150 range but the number 5 was
down in the 120 psi range. I took it to a shop I have access to and
did a leak down test while also checking valve lifter clearances.
All lifter clearneces were within spec although a few on other
cyls. were a very tiny bit over. A second compression test said
that the #5 cylinder had perfect compression but it even jumped up
to 300 PSi at one test.
The leak down did not produce any great findings. At high pressures
up to 180 pounds no leaking could be heard from the throttle body
or from the exhaust pipes. However it sounded like a leak into the
crank case somewhere as you could hear air flowing in through the
oil fill port and in the front of the engine. The air flowing
through the crankcase slowed to almost nothing when it got down to
80 -100 pounds and all cylinders held air fine and leaked only
slowly. The air flowing through what I can tell is the crankcase
happened on all 6 of the cyls. so I assume that is normal.
It began to run a bit better but still rough idle and kind of doggy
at around 50 Mph but will run much better at higher rpms. So I am
thinking I have a broken valve spring or worn guide. Which may
explain the intermitent good compression numbers.
Sorry for the book wanted to be as clear as I could. Just hoping
someone else might have some insight as to why I have this running
condition before I take the plunge and pull the head. I should also
note that I have good fuel pressure and spark. No vacume leaks that
I can find.
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !