2000 V8 Disco TC Lockup

[astormsau]

Hi everyone,
Had a bit of an issue every since I got my car...

Its a 2000 V8 Auto on direct injection gas. There are no faults in the main ECU as far as my scan guage is concerned. Oxy, MAF and TPS and temp sensors all function correctly.

Anyhow my problem is, the torque converter seems to lock up all the time around the 60km/hr mark in Drive.

So I go from 1st to 4th and then lockup the TC. Its okay and the car holds lockup and there are no issues as such, its just that every time you come to a hill the car ends up either unlocking the tc or kicking back to third and I find the constant gear changes annoying as I live in a hilly area.

So sometimes you are doing 65 in 4th with TC locked. You begin to loose speed, put foot down a bit to say 40% on TPS... kicks back to third and then you increase speed so release foot on accelerator to stop speeding... then it goes back to 4th and then locks up again and then you find yourself repeating the process as the speed drops... its a bit annoying.

Using sport mode doesn't seem to make any difference... I thought I had read somewhere that in sport mode it wouldn't lock up until 80km/hr in 4th.

If I drive in 3rd its ok and will lock up in 3rd gear and climbs most hills without a problem... its just weird that the car is so desperate to lockup all the time. Drove my brothers disco 1 the other day, its an auto and it didnt lock up until 80 which meant alot less auto changes....

Any ideas? As far as I know there is no adjustment for kickdown as the auto is driven by TPS.... the Scanguage I have shows the TPS to be reading fine.... throttle cables are correctly adjusted on the intake so i'm a bit stumped.

Drew

[Tombie]

TC lock up in 4th does not occur until 80km/h...

If yours *is* then you have a fault ;)

Other than that its doing everything it should do.. If you dont like the kick down may I suggest..

Use the gear lever and select "3"... Its proven to be more economical in stop start, sub 80km/h traffic...

An Automatic gearbox is no replacement for actual driving :angel:

[Sully]

Hmmm... My auto does flick between 4th and 3rd on hills at around the 60 mark, but only reasonably steep ones and not as much as you're reporting Drew. The speeding up and slowing down certainly doesn't happen on mine. Most of the time it just happy tools along in 4th.
Using 3rd gear and the S mode may be a band-aid solution to another problem. If you feel that it's not behaving as it should, go for a transmission fluid change as a start. Maybe some fresh lubes are all you need.

[Pedro_The_Swift]

Dunno 'bout that
both mine have locked up at 60( on the flat light throttle)

only real men drive manuals huh Tombie,,

[justinc]

Light throttle loads, 60km/h on the flat, ( at operating temp) D2V8 will lock up. BUT, the MAF does have an input, even though no fault codes show up, what Kg/hr readings are you getting???

JC

[Freightdog]

My V8 locks up at 60 also.

[astormsau]

There are no engine codes and last time the auto was serviced (40,000km ago - its just about due for another) they said everything was fine - no fault codes or issues. This behaviour happened before and after the service.

Generally I cruise around town pretty light on throttle, so at 60km/hr I might have 11- 15% throttle according to the TPS and it will go into lockup in 4th. I live out near Eltham in Melbourne (Lower Plenty) and it is one of the hillier suburbs in Melbourne so am constantly climbing up and down hills which means if im cruising along the flat at 60 in lockup then hit a steep hill, it has to kick back to 3rd, some of the hills level out and it goes into 4th and lockup then you hit a hill and then it has to go back to third again to avoid dropping speed.

I suppose its just a characteristic of the car... I just seem to think that for some reason in non sports mode it locks up at 60 but when in sports it locks up at 80... It seems to lock up at 60 in mine regardless of which mode it is in!

Drew

[Fluids]

Hey! Sorry to hijack the thread, but 5/5 V8 drivers above say that the V8 auto locks up at 60km/hr ?? .... in the Td5 it's lockup at 80km/hr in 4th, and 70km/hr in 3rd.

So it appears there is a difference between V8 & Td5 Auto ECU's ??

Locked up at 60km/hr, how many rpm's are you V8 dudes doing ?

... I'd love the Td5 to lockup at 60 .... but it would probably be doing way too few rpm's to hold the load.

[Sully]

At 60 in fourth gear mine runs at about 1600rpm from memory.

[Fluids]

Thanks Sully. My Td5 is doing around 1700-1750 at the point the auto unlocks (70-72km/hr) so 1600 would be around right i guess if it would hold lockup at 60 ...

... at 1600rpm and less the std Td5 is a breathless 98pound weakling ! :p

Drew, the gearbox behaviour you describe sounds about right. The Td5 does exactly the same thing (esp' when driven around at lower engine rpm's and applying heavier loads like hills ... engine's not producing enough HP at that rpm to hold the speed .... and the auto knows it, so it changes down.

Try slipping the stick into 3rd before the hill (allowing enough time for the auto to change down and acheive lockup) and just hold 3rdL until the hill flattens out ...

... apparently the noise you create is something you guys dig anyway ! :eek: :twisted: :twisted: :twisted:

[astormsau]

Fluids, it is a good sound. Yes often I do change back to third, its just interesting that the transmission is really really keen to lock up in third of fourth, much more than most other cars I usually drive such as a VS V6 auto commodore which always waits for a few seconds when you are over 80 before it locks up... the d2 is very keen to lock it in :)

Drew

[rusty05]

Sounds normal.
Mine locks up around 55km- 60km.

Sport mode makes it kick down with a little less throttle.

[Tombie]

It was proven by a few V8 owners that 3rd returns better economy around town.

[Sully]

Yep. Using 3rd around town doesn't provide any noticeable gains in economy.

In follow up to a previous post in this thread. RPM's during lockup at 60 are at around 1300rpm, not 1600.

[bn172]

Hey! Sorry to hijack the thread, but 5/5 V8 drivers above say that the V8 auto locks up at 60km/hr ?? .... in the Td5 it's lockup at 80km/hr in 4th, and 70km/hr in 3rd.

So it appears there is a difference between V8 & Td5 Auto ECU's ??

Locked up at 60km/hr, how many rpm's are you V8 dudes doing ?

... I'd love the Td5 to lockup at 60 .... but it would probably be doing way too few rpm's to hold the load.

gday fluids, v8 & td5 auto ecu's are different,i borrowed one out of a v8 to test a lock up fault in the rattler, it would lock up at 60 insted of 80kph. was not as nice to drive! cheers ben