Hi, I'm new here so be kind to me please!!

I've got an 01 plate Discovery which I regularly use for towing my horses. Last weekend I had towed 85 miles, competed and towed almost back home when, going up a very steep hill, the light came on to say the gear box fluid was overheating. This went off after about a minute and didn't do it again.

The following day, exactly the same thing happened. Yesterday, I only towed 45 miles, competed and towed to the same hill and the light came on again. This time it took 2 minutes to go off but then flashed back on again about 5 minutes later whilst going over speed bumps. This time it went off after about 2 seconds.

My mechanic has checked it over for me and all the levels are fine and he has no idea what is wrong. It doesn't do it when I'm not towing. I don't know where to go from here as I'm meant to be competing at the weekend and have to tow about 150 miles and I'm not sure whether to risk it or not. My mechanic is going to have another look but is really stuck.

Any ideas?

 

One of those Rover things - two sensors operate same warning light. Tranny and transfer case temp. From the owner manual:

the light extinguishes and it is safe to drive).

From the shop manual:




Now the average owner would think this is just the transmission. But the electrical schematic shows the transfer case also has a heat sensor and both can trigger this light. See attached wiring and pictures of sensors. So in addition to low fluid in tranny or transfer case, could also be bad sensor or skinned wired (ground).

So if the the tranny fluid is good, and the transfer case fluid is good (may want to change it to 85W150 for good measure); then may want to unplug sensor when light comes on to verify which sensor is off-normal. Tranny temp sensor more likely of the two to fail. Of course be sure the radiator, the tranny cooler, and the AC condenser are all free from mud and leaves and gunk obstructing air flow. It can get between them and be hard to see.

 

Start by replacing the gear box temp sensor, it is cheap and easy.
Also check the condition of the gear box fluid, if it is not bright pink change it.
Another option is to add on a aftermarket gear box cooler, alittle more money but would be totally worth it in the long run.

Around here all of the guys who plow driveways with their pick up trucks in the winter add aftermarket transmission coolers.

 

Thanks guys, I'll print these replies out for my mechanic and get him to have another look. It's no good me looking, because I'm just a mere female!!

 

First, how many miles on your truck, when were the fluids for the tranny and t/case last changed? Either of them can cause the light to come on. That being said, you need to verify which case is having and problem, don't just start throwing sensors at it.

 

I would have him change the fluids in both and upgrade to the heavier oil for the Transfer case.
And he can take his shop air and blow the radiator area clear of any build-up of debris.

If the tranny did overheat, you want fresh fluids.

 

My Discovery has now spent a week at the garage. There was nothing wrong with the fluids even though it has overheated three times but they changed them anyway.

It was put on a diagnostic machine and apparently the torque convertor was knackered. I have had numerous problems over the last two years with the car having no oomph in hot weather but people said it was my imagination and that Discoveries do not have any oomph! This was replaced and the car runs like a dream and I didn't realise it had so much power!

Yesterday I took it out towing my horses and it was ok in the morning when the weather was cooler (15 degrees centigrade) but after driving 55 miles on the way home, the light came on again (outside temperature 26 degrees). This time it would not go off even after sitting on the side of the road for about 5 minutes. As I was only 10 miles from home I took the chance and drove off again. It spent the next 10 miles with the light going on and off randomly, sometimes when I went up hill, sometimes when I stopped at a junction.

On taking it back to the garage they said they would fit the gear box cooler but cannot get it done before the weekend and I'm meant to be towing Saturday morning. As I'm towing in the morning and coming home the following morning, I'm inclined to take the chance as it will be relatively cool. They have told me not to worry about it especially as the car never smells of burning oil and they will do it next week. Should I worry?

 

Oh and in reply to an earlier post, its done 155,000 miles.

 

Those don't come with gear box coolers, only transmission coolers on the front. You have to run alot of new hoses to get it to work.

 

I have the transmission oil warning light on and off , I replaced the transmission oil yesterday but the warning light is still coming on. What else should I be checking or replacing? Can anyone tell me something?