P38A p38 Rang Rover 2.5td Torque Converter Lock-up

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fiatpandaman

Member
Posts
24
Location
shropshire
Good Afternoon everyone,

As always the first post is a question! Sorry! I have searched around and I think I have the info I need but I just wanted to confirm if its ok.

Its my first experience with an older auto gearbox, I wanted to know when I could expect the gearbox to lockup? I do a lot of country lane driving at about 40mph and its seems its always not locked up, i.e revs fall off load and rise again until I hit about 50mph, then in top gear it locks and all is fine.

This is really frustrating as I feel I need to rev the stuffing of it to go up hills 3.5k (big hills) I expected lockup to occur much sooner and in lower gears?

I know I have an engine thermostat to change as its running very cold at the moment. I have plans to give it a good service over the weekend.

Thanks all very much for reading, and a reply if you can.
 
Torque lock occurs at around 50 MPH in "D" that is normal. Mine locks up at 46 MPH in "D" so yes it is a little frustrating to follow someone on a tight road doing 42 in a 50 or 60 area. If you are losing power on hills i suggest you look at the tech archive section and follow my instructions for checking lift pump function.
 
Ok, not lack of power as such but lack of speed up hills gravity is a harsh mistress, im not used to the car, I worry about things I probably need not worry about.
I had loads of power, the engine wasn't struggling i just didn't seem to be making progress with out lots of revs!

Thanks Kindly for taking the time to reply wammers
 
fiatpandaman said:
Ok, not lack of power as such but lack of speed up hills gravity is a harsh mistress, im not used to the car, I worry about things I probably need not worry about.
I had loads of power, the engine wasn't struggling i just didn't seem to be making progress with out lots of revs!

Thanks Kindly for taking the time to reply wammers
Click to expand...

Think maybe you need to do as i suggested, lots of revs and no speed in top gear could be amongst other things if normal stuff checks out a failing gearbox. You may have a bag of worms there. Do you have any diagnostics?
 
Don't forget these engines were built for a completely different car. Now yours is lugging a 2.2 something ton auto with permanent all wheel drive...over here they have dropped the speed limit to 80kph(50mph) and the old bus doesn't like it at all.. right on the edge of the torque lockup.. it'll drop down to bloody second gear and climb right back through the gears until it's happy to drop back Into torque... However at 84kph it's happy and remains there.
You'll find at 70mph it has a lot of power and will pull like a train but at around 50mph it's a little underpowered...and mine was tuned up!! Around a 100,000mls ago....
It should have been around the same horse power as the V8 really.. and dropping off speed on a hill is about right.. brick! Gravity! Giant lump!:p;)
 
Im not getting in to top gear, were talking about 30-40mph country lanes with very steep hills. Once I am doing 50mph there is no slip. I have a laptop and OBD2 cable but no specific software to test. I have to rev to 3 -3.5k
 
fiatpandaman said:
Im not getting in to top gear, were talking about 30-40mph country lanes with very steep hills. Once I am doing 50mph there is no slip. I have a laptop and OBD2 cable but no specific software to test. I have to rev to 3 -3.5k
Click to expand...
Diagnostics is a dedicated system for the p38 diesel. Nanocom is its name!!
Physical check, oil quality, quantity in the gearbox.
Brown and burnt smelling is not a good thing!!:eek:
 
fiatpandaman said:
Im not getting in to top gear, were talking about 30-40mph country lanes with very steep hills. Once I am doing 50mph there is no slip. I have a laptop and OBD2 cable but no specific software to test. I have to rev to 3 -3.5k
Click to expand...

Torque lock IS NOT top gear. You should be in fourth gear (Top gear) at around 35 MPH. Torque lock is not a gear it just links the engine straight to the gearbox. This occurs around 50 MPH. OBDII is no good on your car it will do nothing. At 3000/3500 RPM in fourth you should be doing over 80 MPH.
 
Last edited:
Hi Warmers, I know torque converter is not top gear, I have established it locks up at 53mph now, great information thanks! Sorry if the question has been asked 100 times, I do thank you for your time.
Ill search what cables I need and software as to not clutter this post. If its of help, I recorded a short clip of a drive out. The hill is reasonably steep (nowhere near as bad as the ones I went up last night)
I can see it goes though the gears I just didnt expect to have to hit on occasion 3.5 to 4k to get it to go up a larger hill. It just seemed that if it had locked at a lower RPM I would have more options to use the power rather than spin fluid.

My other car is a BMW 335i with DSG which makes it a hell of a learning curve for me.



Ordered a themastat as well as its running cold (and no more driving till its done)
 
fiatpandaman said:
By the time I get to the bottom of the hill the temperature drops back down to cold, hence i suspect the stat is stuck in the open position.
Click to expand...
Ok, good point, I had a problem a while ago were the ecu temp sender was duff on the cylinder head!
I would get torque lockup at the 11oclock position on the gauge and it would drop down due to the temp sender having a wobbly head on it. Thus the torque lockup on mine would and wouldn't work depending on the sender, after replacing both of mine, the temp gauge sender and the engine ECU temp sender, the problem disappeared. Ok , to the point...
When fitting your thermostat make sure the little bleed hole in it is at the twelve o'clock position.;)
 
Mark, thanks, I suppose its possible engine temp has an effect on how and when this locks up as well as gear changes.
Advice taken and noted as regards the Thermostat, Should have a busy weekend!
thanks.
 
fiatpandaman said:
Mark, thanks, I suppose its possible engine temp has an effect on how and when this locks up as well as gear changes.
Advice taken and noted as regards the Thermostat, Should have a busy weekend!
thanks.
Click to expand...
The gearbox will behave slightly different when cold as well as it will hang on a bit longer in gear to warm the oil.
Is it a pre 99' P38?
Always stick your buses year and engine details in the start of your threads.;)
...And welcome to a good few busy weekends:cool:
 
fiatpandaman said:
Good Afternoon everyone,

As always the first post is a question! Sorry! I have searched around and I think I have the info I need but I just wanted to confirm if its ok.

Its my first experience with an older auto gearbox, I wanted to know when I could expect the gearbox to lockup? I do a lot of country lane driving at about 40mph and its seems its always not locked up, i.e revs fall off load and rise again until I hit about 50mph, then in top gear it locks and all is fine.

This is really frustrating as I feel I need to rev the stuffing of it to go up hills 3.5k (big hills) I expected lockup to occur much sooner and in lower gears?

I know I have an engine thermostat to change as its running very cold at the moment. I have plans to give it a good service over the weekend.

Thanks all very much for reading, and a reply if you can.
Click to expand...
I hold mine in 3rd with the gear lever in those sort of conditions, the torque convertor locks up at about 40mph or a bit less then.
 
wammers said:
Torque lock IS NOT top gear. You should be in fourth gear (Top gear) at around 35 MPH. Torque lock is not a gear it just links the engine straight to the gearbox. This occurs around 50 MPH. OBDII is no good on your car it will do nothing. At 3000/3500 RPM in fourth you should be doing over 80 MPH.
Click to expand...
Not up hill with no TC lock up.
 
fiatpandaman said:
Hi Warmers, I know torque converter is not top gear, I have established it locks up at 53mph now, great information thanks! Sorry if the question has been asked 100 times, I do thank you for your time.
Ill search what cables I need and software as to not clutter this post. If its of help, I recorded a short clip of a drive out. The hill is reasonably steep (nowhere near as bad as the ones I went up last night)
I can see it goes though the gears I just didnt expect to have to hit on occasion 3.5 to 4k to get it to go up a larger hill. It just seemed that if it had locked at a lower RPM I would have more options to use the power rather than spin fluid.

My other car is a BMW 335i with DSG which makes it a hell of a learning curve for me.



Ordered a themastat as well as its running cold (and no more driving till its done)
Click to expand...

Test the stat in boiling water before fitting and fit with the bleed hole at the top.
 
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