red warning light

Hello everyone,

I would like to submit the following problem : I have a Discovery series 2
with a minor (?) problem. After driving for 30 min, a red warning light
appears on the dashboard. It's the light for the oil temperature of the
(automatic) gearbox. Strangely enough the light goes off when I drive on the
highway. The car was checked in the garage but the computer checkup didn't
reveal anything wrong. The car drives fine, no specific noise, no oil stains
on the garage floor, no nothing. The mechanics think it's a wiring problem,
nothing to worry about. But I do worry : why does the light go off when on
the highway ? Due to better ventilation, or because the gearbox doesn't have
to change gears often ?

thanks for any input.

Pierre
Belgium

Pierre Francois wrote:

|| Hello everyone,
||
|| I would like to submit the following problem : I have a Discovery
|| series 2 with a minor (?) problem. After driving for 30 min, a red
|| warning light appears on the dashboard. It's the light for the oil
|| temperature of the (automatic) gearbox. Strangely enough the light
|| goes off when I drive on the highway. The car was checked in the
|| garage but the computer checkup didn't reveal anything wrong. The
|| car drives fine, no specific noise, no oil stains on the garage
|| floor, no nothing. The mechanics think it's a wiring problem,
|| nothing to worry about. But I do worry : why does the light go off
|| when on the highway ? Due to better ventilation, or because the
|| gearbox doesn't have to change gears often ?
||
|| thanks for any input.
||
|| Pierre
|| Belgium

Do you mean that the light comes on when driving off-road, but goes out when
you return to normal road driving? The autobox will be working harder
off-road, so that would explain the difference in temperature. However,
your Disco should be easily capable of driving off-road without cooking the
autobox. I doubt if it's a wiring fault, unless the light flashes, when it
could be a faulty connection. If the light stays on all the time, a wiring
fault is unlikely.

Which leaves the question, why is it overheating? I would check the
transmission oil cooler first. If this was blocked with mud, it could give
the symptoms you describe. I had the same problem on a Disco 1 - got the
oil cooler caked in mud, and overheated the autobox when towing a caravan on
the way home, which had never happened before. The oil cooler is located
below and in front of the radiator. I would check this first.

--
Rich
==============================

I don't approve of signatures, so I don't have one.

Thanks Richard,

but I'm almost ashamed to confess that I was speaking off-highway, not
off-road.... My disco hasn't seen much mud ever. The light goes on and off
but the intervals are long (eg 5 min on, 10 min off, or like yesterday on
the highway 30 min off, and on normal roads 30 min on). Could there be
something wrong with the temperature probe (I suppose there is such a thing
in the gearbox). The mechanic said there were two possible causes : faulty
wiring, or a faulty sensor. I'll check the oil cooler, thanks for the tip.

Pierre

Pierre Francois wrote:

|| Thanks Richard,
||
|| but I'm almost ashamed to confess that I was speaking off-highway,
|| not off-road.... My disco hasn't seen much mud ever. The light goes
|| on and off but the intervals are long (eg 5 min on, 10 min off, or
|| like yesterday on the highway 30 min off, and on normal roads 30 min
|| on). Could there be something wrong with the temperature probe (I
|| suppose there is such a thing in the gearbox). The mechanic said
|| there were two possible causes : faulty wiring, or a faulty sensor.
|| I'll check the oil cooler, thanks for the tip.
||
|| Pierre

If there's no obvious blockage to the oil cooler, I would take it to a
dealer and have them put it on TestBook. This will reveal faulty sensors
and the like.

--
Rich
==============================

I don't approve of signatures, so I don't have one.