Auto won't change down from 5th

Armymick · 19th December 2015, 15:16

Evening folks,my newly bought diesel cdti auto 05 plated contemporary se has a problem. When on motorway in 5th and slowing down to say 55mph at 1500 revs the car will not change down into a lower gear. This results in much juddering as it tries it's hardest to pull away at low revs still in 5th. I have disconnected the battery for an hour as suggested to reboot the ecu but it still does it in drive. The car goes up the box no problems and in 3 and 4 OK any ideas and if anyone can recommend a rover guy in Kent area would be very grateful as I intend to take the family to Scotland for Chimbo.

humphshumphs · 19th December 2015, 15:24

Put you foot down a bit further and it'll kick down..... mine does anyway

SD1too · 19th December 2015, 18:13

Quote:

Originally Posted by Armymick

When on motorway in 5th and slowing down to say 55mph at 1500 revs the car will not change down into a lower gear. This results in much juddering as it tries it's hardest to pull away at low revs ...

Mick,

It's possible that this is a phenonemon peculiar to the diesel engine because I've a feeling that someone else has reported it. Hopefully a diesel expert will be able to confirm or dismiss that.

Whatever it is, it is much more likely to be the result of an engine problem than a fault with the automatic gearbox. Your best bet would be to wait for advice from diesel owners on this forum.

Simon

RPWC · 19th December 2015, 18:21

Wish I could be of help, but it's a new one on me Simon, never heard of it before. Sounds like a possible T4 diagnosis would throw up some answers?
Edit. Your nearest T4 operator is Kenton, based in Borehamwood

http://www.the75andztclub.co.uk/foru...er.php?u=23084

Dragrad · 19th December 2015, 23:37

I've come across this issue on several occasions, and I have reached a conclusion that it only happens when speed and road angles change rapidly as well as maybe in conjunction with light braking, and then a touch on the throttle followed by a quick release, etc.... This causes a judder in mine, but another, firmer, brief touch to the throttle sorts it out..... when I leave the S-bend, with a downward approach and a rising exit, also having been under a 2 mile rise in altitude prior to the short S-Bend.......

I have talked to other members about this issue, and TBH it appears that it is a set of circumstances that throw the "brain" into a bit of a confused state

I just live with it.... (BTW Fluid in Gearbox id correct and is warm when it happens)

Yella Fella · 20th December 2015, 05:07

Just a thought, as my knowledge of auto boxes is minimal having owned only one auto (lexus GS3000) previously. On the usual TV car programs like auto trader etc, if they have a slow or problematic auto gear change they always change the transmission fluid with good results. Im sure transmission fluid can become "exhausted" and doesn't work as it should and needs to be changed. Maybe its worth having yours checked to see how fresh it is.

SD1too · 20th December 2015, 08:07

Quote:

Originally Posted by Dragrad

... I have reached a conclusion that it only happens ... maybe in conjunction with light braking ...

Braking might well be very significant Andrew, but the OP doesn't mention it.

Mick, can you let us know whether or not you have applied the brakes when this phenonemon happens?

Simon

freck · 20th December 2015, 08:09

Quote:

Originally Posted by Yella Fella

Just a thought, as my knowledge of auto boxes is minimal having owned only one auto (lexus GS3000) previously. On the usual TV car programs like auto trader etc, if they have a slow or problematic auto gear change they always change the transmission fluid with good results. Im sure transmission fluid can become "exhausted" and doesn't work as it should and needs to be changed. Maybe its worth having yours checked to see how fresh it is.

Yes I remember on Wheeler Dealers that they had a Porsche Boxster with a faulty auto box which was fixed with just an oil and filter change.

zedhed · 20th December 2015, 08:16

As stated,first port of call would be a fluid change when it comes to problems with autobus,which reminds me,still got the missus signum to do yet

.

James.uk · 21st December 2015, 01:54

Next time it happens use the gear lever to engage 4th gear, if it still wont change then change the oil. if it changes OK, try planting your foot on the go faster pedal, diesels are not as sensitive as petrol engines innit, so give it some welly...

...

19th December 2015, 15:16	#1
Armymick Newbie 75 cdti saloon Join Date: Dec 2015 Location: Deal Posts: 19 Thanks: 5 Thanked 1 Time in 1 Post	Auto won't change down from 5th Evening folks,my newly bought diesel cdti auto 05 plated contemporary se has a problem. When on motorway in 5th and slowing down to say 55mph at 1500 revs the car will not change down into a lower gear. This results in much juddering as it tries it's hardest to pull away at low revs still in 5th. I have disconnected the battery for an hour as suggested to reboot the ecu but it still does it in drive. The car goes up the box no problems and in 3 and 4 OK any ideas and if anyone can recommend a rover guy in Kent area would be very grateful as I intend to take the family to Scotland for Chimbo.

19th December 2015, 15:24	#2
humphshumphs I really should get out more....... No longer a Rover Owner Join Date: Jan 2011 Location: As far east as you can go in the UK and not get wet feet. Posts: 2,273 Thanks: 404 Thanked 309 Times in 246 Posts	Put you foot down a bit further and it'll kick down..... mine does anyway __________________ Richard. No longer a 75 owner as my tourer made it to the moon, and died on it's way back. But 1/4 million miles ain't bad.

19th December 2015, 18:21	#4
RPWC This is my second home 75 model car Join Date: Apr 2011 Location: Newcastle upon Tyne Posts: 20,182 Thanks: 4,008 Thanked 5,083 Times in 3,114 Posts	Wish I could be of help, but it's a new one on me Simon, never heard of it before. Sounds like a possible T4 diagnosis would throw up some answers? Edit. Your nearest T4 operator is Kenton, based in Borehamwood http://www.the75andztclub.co.uk/foru...er.php?u=23084 __________________ Cheers. Rich… Last edited by RPWC; 19th December 2015 at 18:29..

19th December 2015, 23:37	#5
Dragrad This is my second home *None DROWNED** Join Date: Aug 2007 Location: Cardigan Posts: 33,339 Thanks: 1,257 Thanked 1,664 Times in 1,081 Posts	I've come across this issue on several occasions, and I have reached a conclusion that it only happens when speed and road angles change rapidly as well as maybe in conjunction with light braking, and then a touch on the throttle followed by a quick release, etc.... This causes a judder in mine, but another, firmer, brief touch to the throttle sorts it out..... when I leave the S-bend, with a downward approach and a rising exit, also having been under a 2 mile rise in altitude prior to the short S-Bend....... I have talked to other members about this issue, and TBH it appears that it is a set of circumstances that throw the "brain" into a bit of a confused state I just live with it.... (BTW Fluid in Gearbox id correct and is warm when it happens) __________________ Andrew Ich Dien Problem solving is... lateral thinking SEARCH FIRST ...ASK LATER...

20th December 2015, 05:07	#6
Yella Fella Nemo Me Impune Lacessit None at the moment Join Date: Nov 2007 Location: Glasgow's HMP Barlinnie, 'A' Hall, 2nd Flat Posts: 5,192 Thanks: 493 Thanked 1,094 Times in 666 Posts	Just a thought, as my knowledge of auto boxes is minimal having owned only one auto (lexus GS3000) previously. On the usual TV car programs like auto trader etc, if they have a slow or problematic auto gear change they always change the transmission fluid with good results. Im sure transmission fluid can become "exhausted" and doesn't work as it should and needs to be changed. Maybe its worth having yours checked to see how fresh it is. __________________ [SIGPIC][/SIGPIC]

20th December 2015, 08:16	#9
zedhed Posted a thing or two zt saloon turbo Join Date: Sep 2015 Location: Tipton Posts: 1,461 Thanks: 1 Thanked 167 Times in 132 Posts	As stated,first port of call would be a fluid change when it comes to problems with autobus,which reminds me,still got the missus signum to do yet.

21st December 2015, 01:54	#10
James.uk Passed Away 2002 Pale Blue. Rover 75 CDTi Connoisseur auto. 170K miles Join Date: Dec 2008 Location: Near the M67. Posts: 14,509 Thanks: 199 Thanked 585 Times in 397 Posts	Next time it happens use the gear lever to engage 4th gear, if it still wont change then change the oil. if it changes OK, try planting your foot on the go faster pedal, diesels are not as sensitive as petrol engines innit, so give it some welly... ...