I get the occasional smoke blast out from under the passenger side of the
car and determined a while ago that it was transmission fluid. I made the
assumption, based on some advice from a fellow Jag-Lovers bud, that the
transmission vented a little when I ran at high RPMs. Since I do that
regularly, I know the transmission was a little over-filled on the last
service, and there is no evidence of a leak on the garage floor, I shrugged
and left it at that.
Now it’s happening more often and not always at high RPM drives. I ran just
a few errands the other day - beautiful 75 degree weather with bright sun,
35 mph or thereabouts for under an hour … stoplight = smoke. Every
stoplight = smoke. Took her out at 50-80 mph for two or three hours
yesterday - 60-70 degrees most of the trip at mostly at sunset and night -
no smoke, but found a drip on the cats that was clearly ATF. So now I’m
wondering if things need to be “more hot” to get the smoke, but the drip is
always there under pressure.
Thanks for the indulgence on the history. Now for the diagnosis … Like I
said, it will not leak when not running. I can’t even get it to leak idling
in the garage. This seems to be an at-speed only issue. I had the car up
on ramps this weekend and last, and am seeing the same thing in both cases:
there’s a line over the resonator that’s wet with ATF and seems to hold a
drip in reserve just waiting for the opportunity to drop off onto the
exhaust at all times. However, the line itself doesn’t seem to be leaking.
It’s just covered. I checked the dipstick to make sure (since it was a
little over-filled last time) it wasn’t coming up out of the tube at temp
… perfectly dry (I figured this pan was a little shallow for that, but my
Lincoln used to do that, so I thought I’d rule it out anyway). The vacuum
modulator is supposed to be new (long story), and doesn’t seem to be leaking
In short, I can’t find ATF anywhere other than this line and the expected
splatter area, but the splatter area covers enough territory (including the
line itself) that I can’t figure out where the original leak is coming from.
Yes, I’ve cleaned it up, taken it out, and looked again. When I bring it
back, it’s just the same There’s never just one little drip somewhere as
a clue, there’s always a splatter covering that line and the surrounding
Since I can’t duplicate the problem where I can actually see it happen, does
anybody have any knowledge of “common problem” spots I should be looking at
for this leak? Or am I just going to have to wait until it’s bad enough to
start dripping at idle to find it?
'88 XJ-SC Lucas CEI (Bagheera)
'90 XJ6 Sovereign (Bob)
Alexandria, VA US
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