3.5 EFI oil light and auto gearbox problem

Hi I have just bought a range rover 3.5 EFi i took it in for a mot saturday 6 miles each way, On the way home when i pulled up to the traffic lights the oil light started to flash with the Revs very low rest foot on the throttle so engine runs smooth like it was on the way to the MOT and the oil light goes out any ideas what it could be?

The Auto gearbox also only has 2 gears the oil level seems ok so would it need replacing or would it be something more serious?

Thanks Pete

Thicker oil would sort your light out.

It would probably appreciate 20w50 mineral anyway.

Cheers

The oil light will flash if the engine revs are that low and the engine is about to stall, lots of info in the forum already on stalling V8s.
Auto gearbox with only two gears and the fluid "level seems ok" could be serious (a replacement box), when was the fluid and filter last changed?

I guessed the oil light was flashing because of the revs I have a oil pressure guage fitted on the car but its not working, where would i find the sender unit on the engine? i dont know what the revs was at as the rev guage doesnt work need work out why...

I dont know when the gearbox oil was changed but i will try get a filter for it i have 5 litrs of ATF oil but guessing im going to need more.

Your oil presure guage will have it's own sender and will connect via a T piece to the the oil pressure switch position which is near the oil filter, so remove the pressure switch screw in T piece and fit sender and switch. OR leave the switch off and fit the the sender on it's own.

Yes 5.ltr max as you are unable to drain the torque converter. Some say drain the gearbox and refill then drain again but also change the filter and refill 100 miles later.
I get a Garage to replace my fluid and filter due to the work involved but I have never had to go back but they use a machine to remove all the fluid.

you may find it wont change out of first a while after changing the fluid as it will dilodge all the crud in the box and block the govenor, but it sounds like the box has had it anyway. is it normally a 4 speed zf gearbox?

Ok i will do the oil pressure tonight along with changing the gearbox fluid hopefully it will start to work.

not sure you read my post right, but never mind- you have nothing to loose on the gearbox now anyway.

which box is it?

fett said:

you may find it wont change out of first a while after changing the fluid as it will dilodge all the crud in the box and block the govenor, but it sounds like the box has had it anyway. is it normally a 4 speed zf gearbox?

Click to expand...

I dont know what gearbox is in it i think it should be a 4Speed its been sat around for 2-3 years.
Im new to V8s so dont know alot about them.

Ped87 said:

I dont know what gearbox is in it i think it should be a 4Speed its been sat around for 2-3 years.
Im new to V8s so dont know alot about them.

Click to expand...

Anyway what are the two gears you only get and how do you know??.
I never know what the gear my discos is in unless I move the selector and see the engine revs change.
In and out of lockup is the only time I can notice a difference and then not always.

you see if it was t eolder 3 speed it might jut need adjusting of th bands to get your 3rd ear back.

if its a later 4 speed which from memory it should be then you have lost half the gears.

which gears do you have? if its just first and the a change at about 50mph (which would be hard to et to in first) then it might just be the govenor which is stuck and it locking the torque convertor at 50 ish

I believe it to be 1st and 2nd as you can select it on the stick.
Ive put it into 1st then drive up the road move it to 2nd and it changes and you can feel it change but when you move it into 3rd or D nothing else happens.

I think its getting to about 20mph when it changes will have to put the sat nav in and check again as the speedo does not work.

ok but it doesnt change up to third or 4th when you get going a lot faster?

just moving the stick on the auto to 3rd at say at 10mph wont make it change in to 3rd for example at 10 mph it will just mean its allowed to cange in to 3rd when up to the correct speed.

No doesnt change had it upto about 50mph and it didnt change up as sounded like it was reving fairly high we slowed down again to about 35-40mph.

We have been driving along and then tried to make it change down from D to 3rd no change in revs then down into 2nd and again we didnt have any change easied off the throttle bit more and changed it down to 1st and it changed.

i dont know if my selector is out slightly as when you move the stick to R its between R and N i dont know if this would mke any difference?

well read this so you know what can happen if you change the oil its from ashcrofts website:

I have a 4 speed ZF Auto and it sticks in first gear in the morning or when cold and is reluctant to change up from 1st gear. Once the gearbox has warmed up it shifts normally. Why?

The governor valve is sticking, which can be caused by contamination. i.e. clutch plates or other parts disintegrating. The fine debris finds its way past the filter and tends to accumulate in the governor, causing it to stick. A temporary solution is to remove and clean the governor. The problem will often recur as debris from damaged parts continues to build up in the governor. If the problem continues after cleaning the governor then it may be necessary it replace your Autobox.

We have noticed many customers reporting this fault starting a few days after an oil and filter change and after researching this using our experience and the expertise of others in the trade we have come to the conclusion that as ATF oil is a detergent type oil, when the oil is changed this will dislodge and stir up settled debris in the autobox which in turn jams the governor valve. In light of this although it sounds controversial it is debateable if changing the oil and filter is a good idea, some say if the box it going to fail it will fail if the oil is good or bad and their advice is leave it alone. I am still undecided but the truth is I get a lot of calls from customers thinking they are looking after the autobox by servicing it and a few days later this fault occurs.

Then decide if you should change the oil. In your rare case I think you have little to loose if you do as it sounds like its kncackered anyway. Mybe give ashcrofts a call to ask them there opinion, Dave there seems to know a lot!

Ped87 said:

Hi I have just bought a range rover 3.5 EFi i took it in for a mot saturday 6 miles each way, On the way home when i pulled up to the traffic lights the oil light started to flash with the Revs very low rest foot on the throttle so engine runs smooth like it was on the way to the MOT and the oil light goes out any ideas what it could be?

Click to expand...

Sticking oil pressure relief valve, a common thing. Get a new one, they are cheap and easy to replace.

I started the car up last couple evenings fires up fine runs fine warms up soon as its warm the engine starts to run lumpy sounds like its struggling to stay running.

I need to get it running properly before i can sort out the auto box.

I have a 3.9 and auto box sitting in the workshop very tempted to just fit that but then its all the wiring and i dont know how well that one runs.

box will be similar except the shifts will be timed a little different. if you were gonna swap engine and box you would want all the ecu and loom etc from the 3.9's orginal install. the 14cux that runs the 3.9 is a lot better than the 14cu that runs the 3.5 so it would be worth doing.

Right I've now got the engine running spot on. The gearbox does change out of 2nd but you have to be really revving it hard and it will change gear is there any adjustments that can be made? The kick down cable has slack in it after you have opened up the throttle fully once you have given it a wriggle where orgies into the gearbox it will go tight again is this causing any problems?

kick down cable will need to be set properly for correcct operation of gears ,3.5 and 3.9 are the same box apart from valve block ,if it struggles to change gear kickdown cable or govenor in rear housing ,providing oils isnt blackish