Go Back   The 75 and ZT Owners Club Forums > The 75 and ZT Owners Club Forums > Technical Help Forum
Register FAQ Image Gallery Members List Calendar Mark Forums Read
Notices

Reply
 
Thread Tools Display Modes
Old 21st June 2019, 09:16   #1
Alanbp
Regular poster
 
Rover 75 Tourer Auto Diesel

Join Date: Mar 2016
Location: Aberdeen
Posts: 54
Thanks: 0
Thanked 6 Times in 6 Posts
Default CDT Auto "Chugging" at lower speeds

Hi Folks
I have noticed over the last few months that my 2002 165k miles CDT Auto Tourer does what I can only describe as "chugging" at lower speeds - especially when warm and slowing down. Classic occurance is when I have been cruising at 60 on an A road, come to a village with a 40 mph limit and as the car slow to a steady 40, it exhibits similar symptoms to being in a manual car in too high a gear. If I press the accelerator pedal it stops. Gearbox has fresh fluid in it and performs faultlessly (by & large) wondering if it might be fuel related? Its got a Ron Box on (last £12k miles) Need to try in sports mode to see if its better, ie change down sooner.

Anyone else had this?

Cheers
Alan
Alanbp is offline   Reply With Quote
Old 21st June 2019, 10:49   #2
Vossy
Why? ...
 
Vossy's Avatar
 
MG ZT+ Cdti Auto saloon.

Join Date: Jul 2014
Location: Blockeswich, South Staffs
Posts: 1,545
Thanks: 173
Thanked 483 Times in 330 Posts
Default

I have exactly this with mine, 2003 CDTi, it feels just as if it's locked into a higher gear at 30 mph, when it's in sports mode it doesn't do it, using sports mode does make these diesels drive a hell of a lot better (in my humble opinion).
I don't have a tuning box on my car though so I doubt that is the problem.
Vossy is offline   Reply With Quote
Old 21st June 2019, 18:25   #3
COLVERT
This is my second home
 
R75 Saloon.

Join Date: Feb 2009
Location: France/or Devon.
Posts: 14,003
Thanks: 3,851
Thanked 2,167 Times in 1,816 Posts
Default

Possibly fuel related due to slightly clogged injectors.---Poor spray pattern will show more at low engine speeds.---
COLVERT is offline   Reply With Quote
Old 21st June 2019, 19:13   #4
Mickyboy
SERVICING AND DEALER DIAGNOSTICS
 
Mickyboy's Avatar
 
MG ZT CDTI 135 + & MGZT CDTI AUTO 160 & ROVER 75 TOURER CDTI 160 TROPHY YELLOW

Join Date: Aug 2013
Location: Hernebay
Posts: 4,331
Thanks: 818
Thanked 2,414 Times in 1,141 Posts
Default

Quote:
Originally Posted by COLVERT View Post
Possibly fuel related due to slightly clogged injectors.---Poor spray pattern will show more at low engine speeds.---
Yep seen that many times, very good advice
Mick
__________________
[SIGPIC][/SIGPIC]
T4 Owner
Jobs done : new UBP, Spy hole mod, Rear hub(wheel bearing),plenum cleaned and emptied, Inline thermostat fitted,Full service, In car Digital tv/DVD Bluetooth Satnav etc, Replaced UBP, Restored headlights,Fixed airbag connection.replaced HP pump,replaced rear light seals,changed intercooler O rings.

Jobs to do: ,replace drivers lock,.
[/SIZE]
Mickyboy is offline   Reply With Quote
Old 23rd June 2019, 20:15   #5
COLVERT
This is my second home
 
R75 Saloon.

Join Date: Feb 2009
Location: France/or Devon.
Posts: 14,003
Thanks: 3,851
Thanked 2,167 Times in 1,816 Posts
Default

If only these guys would come back and read the answers to their questions.----
COLVERT is offline   Reply With Quote
Old 24th June 2019, 09:11   #6
Vossy
Why? ...
 
Vossy's Avatar
 
MG ZT+ Cdti Auto saloon.

Join Date: Jul 2014
Location: Blockeswich, South Staffs
Posts: 1,545
Thanks: 173
Thanked 483 Times in 330 Posts
Default

Quote:
Originally Posted by COLVERT View Post
If only these guys would come back and read the answers to their questions.----
Hi, I came back yesterday and read the replies. I didn't see the need to post any more details to what I added.

The next time I am near a T4 or I can get to one of the meetings I may have it looked at but seeing as I drive most of the time in sports mode it doesn't bother me that much.
Vossy is offline   Reply With Quote
Old 24th June 2019, 09:38   #7
BigRuss
Premium Trader
 
BigRuss's Avatar
 
75 CDT Tourer,2.5 Launch Saloon, Omipro MG/Rover (T4)

Join Date: Jul 2007
Location: Liversedge, West Yorkshire
Posts: 5,405
Thanks: 1,105
Thanked 1,340 Times in 661 Posts
Default

It's a common problem, that seems to be particular with the diesels

A quick tap on the accelerator usually prompts the gearbox to change down and all it then well.

There isn't a great deal you can do about it I'm afraid it's down to the poor software in the autobox ECU

Russ
__________________


Replacement Key Service
http://https://the75andztclub.co.uk/...d.php?t=244732
Full T4 Testbook diagnostics available.
Diesel ECU repair and replacement.
Options enabled or disabled as required.
Diesel X-Power 135 and 160bhp, Rover 1.8T 150 to 160
MG 160 V6 to 177 upgrades available
P.M. for details.
BigRuss is offline   Reply With Quote
Old 30th July 2019, 08:48   #8
Alanbp
Regular poster
 
Rover 75 Tourer Auto Diesel

Join Date: Mar 2016
Location: Aberdeen
Posts: 54
Thanks: 0
Thanked 6 Times in 6 Posts
Default

Thanks for the replies. The weird thing is that it seems to be a recent change and I suspect that the injectors are part their best. Its at 165k miles now. Probably original injectors. I do use Miller's Ecomax. Though not every tank. Its fitted with a Rover Ron box but it was ok when I first fitted it. Much better in sport mode and doesn't do it when in that.
Alanbp is offline   Reply With Quote
Old 30th July 2019, 11:42   #9
Vossy
Why? ...
 
Vossy's Avatar
 
MG ZT+ Cdti Auto saloon.

Join Date: Jul 2014
Location: Blockeswich, South Staffs
Posts: 1,545
Thanks: 173
Thanked 483 Times in 330 Posts
Default

Quote:
Originally Posted by BigRuss View Post
It's a common problem, that seems to be particular with the diesels

A quick tap on the accelerator usually prompts the gearbox to change down and all it then well.

There isn't a great deal you can do about it I'm afraid it's down to the poor software in the autobox ECU

Russ

Quote:
Originally Posted by Alanbp View Post
Thanks for the replies. The weird thing is that it seems to be a recent change and I suspect that the injectors are part their best. Its at 165k miles now. Probably original injectors. I do use Miller's Ecomax. Though not every tank. Its fitted with a Rover Ron box but it was ok when I first fitted it. Much better in sport mode and doesn't do it when in that.
As Russ says, poor software in the autobox and that's why running in sport mode cures it. I wish mine would be default in Sports Mode and then the switch was for economy instead of the other way round.
Vossy is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 16:58.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © 2006-2023, The Rover 75 & MG ZT Owners Club Ltd