Hi all

in my 2003 v8 rangie i get an odd issue.

Simply put, the gearbox goes into safe mode (without any alarms on dash) when it apparently gets hot. Not hot as in idling or driving on motorway, but when the gearbox is exercised a lot around town after perhaps of 1.5hrs (lots of roundabouts and traffic lights).

when the fault occurs, i can turn ignition off and on, and behaviour continues until the gearbox cools down.

Ways to overcome the issue are:
1) turn off and come back in 2 hrs
2) continue to drive at higher speed which seems to cool it down because its not shifting from 1st, 2nd and 3rd often
3) idle in car park for 20 mins in neutral

its an odd one because there are no faults on the dash,

gearbox oil changed about 5000 miles ago, including wiring loom (to fix gearbox temp sensor issue - ironic eh)

i don't know whether its terminal or what... ideas welcomed! FFRR 2003 Vogue V8

blocked / ineffective ATF cooler perhaps?

worth looking at for sure. but if the cooler is blocked, why do i not get a transmission overheat warning.

its odd, because it only happens when the gearbox is exercised a lot over a good hour or more. if you are cruising in 4th or 5th, never an issue. FFRR 2003 Vogue V8

possibly the gearbox oil being low.. ... - .- -.




Y. O. L. O.
.

thanks - good note. I can get that checked shortly. In theory not, as it was topped up not long ago after a change. When the oil was low, i was getting gearbox "slips" when pulling out of junctions, often when cold. No issues like that now.

will add to the list of things to check.

just odd why its fine all the time you are not over exercising the box.... i can drive 300 miles and it be fine. I can do 20 miles stop start driving and it throws a spaz FFRR 2003 Vogue V8

I've had the gearbox go into cooling mode (holding gears high revs etc) but I also had a leaking radiator and made the assumption that the bottom rows of the rad were blocked and not cooling the gearbox sufficiently. Radiator has been changed and no problems so far.

I had the problem after sitting in traffic for an hour of so. "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone

That's the most interesting one yet!
i also have a slight leak on the main engine rad (leaves a little puddle on front nearside) and that's on my "list" of things to do.

Can you (or someone else) explain how the gearbox cooling interlinks with the main rad? Anyone got a diagram or well annotated verbiage?

If that solves it, then i may not chop in the rangy, as i was worried about the gearbox! FFRR 2003 Vogue V8

no worries - just found this - is this what you mean?

http://www.justanswer.com/car/4oszw-find-f...issue.html FFRR 2003 Vogue V8

Yep that's the one. The lower 8 rows of the radiator help cool the gearbox. Mine were clogged up as well as the rad having a leak. From what I have read it is a common issue on range rovers of the age of mine (2004). "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone

When you say “the gearbox goes into safe mode (without any alarms on dash)“ I assume you mean it locks in gear and doesn’t upshift or downshift, even when pulling away from rest? Can you tell which gear it’s locking in - 4th or 5th. This is significant.

If it helps, 5th is geared at 30 mph/1000rpm and 4th at 24mph/1000rpm.

Phil

Hi MRP - i will change the Rad and see if that helps - needs changing anyway due to the leak (have to put in about a litre a week at the moment which is diluting the coolant quickly.

Can i use any OEM rad, or do they have mixed bag of issues too?

Hi RRPhil - Great to see you are still on here!
The doc i sent explaining the issue does describe the symptoms spot on:

"The customer may experience high engine speeds and/or transmission shift problems after driving for 25 minutes or longer" --- True

"...caused by the *depletion of the coolant corrosion inhibitor*. --- True, when i bought the car, the was no coolant in it (just water), probably because of this leak

"As a result, the transmission is inclined to change down to lower gears to keep the engine speed (and therefore the cooling) to its optimum" --- consistent with its behaviour. I doesn't want to change up unless you push over 4000rpm, which is crap when you are in town. It also changes down aggressively when slowing


Also found this post which has more detail - looks plausible FFRR 2003 Vogue V8

If your transmission will upshift & downshift then it isn't in failsafe mode.

Does sound like an overheating fluid issue. The TRANSMISSION OVERHEAT message won't be triggered until the fluid temperature gets to 140 deg.C

http://www.fullfatrr.com/forum/topic14434.html

Phil

cheers! FFRR 2003 Vogue V8

Ok so I had / have the very same problem. Like you I also had a leaking rad which I have now had replaced at a main dealer but used a part supplied by duckworth. The rad is now Perfect however today I was in lots of slow traffic and the old gearbox issue happened again. Holding lower gears for higher revs until the gearbox had cooled sufficiently at which point it goes back to normal operation.

I've not had the gearbox oil checked but it is due for a service in a couple of weeks so will get them to look at the oil level and also see about the oil cooler being flushed out.

The investigation continues......... "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone

Hy all,

I suffered this problem a few years ago.No warnings on dash but gearbox employed the Cooling strategy to get the oil temperature down after a bit of driving/towing/sitting in traffic/or pulling up a long hill.Turning it off and on cleared the fault for a while only for it to return....

We Found a little leak in rad,assumed that was it,changed it and it solved the problem for a short while.There is a TSB about gearbox which you mentioned above.Katash is right about the transmission oil cooler.It has a flaw where it tends to block up over time at the inlet pipe which in turn slows down oil flow,reducing cooling effectiveness and then the gearbox starts to overheat.I had a small leak in radiator but in hindsight changing the rad is a waste of money as it is limited in the maximum heat energy which it can remove from the engine and the transmission oil cooler.Putting a new rad in just brings the cooling system back to 100% effectiveness but the problem ain't in the coolant system....

During this issue with my rangie,It would whine and shunt into gears as the gearbox oil was slowly being cooked by the transmission.budget for a new ATF cooler,ATF fluid and filter and you'll be sorted.I have done 30000 miles since this job and gearbox has been fantastic........touch wood