View previous topic :: View next topic |
Author |
Message |
Doglet
Joined: 04 Jun 2022 Posts: 49 Location: Wantage
|
Posted: Fri Jul 29, 2022 13:05 Post subject: V6 auto box losing o/d 4th gear |
|
|
Hi.
Any advice on an odd problem with the auto box in my V6 2003? All four gears shift happily when cold (oil has been changed) but after about 30-40 miles, when it downshifts to third (for instance, uphill) it won't shift back into o/d 4th. Stays with only three gears until it has cooled down.
Dashboard light works when manually pressing the button and shifts from 4th to 3rd when cold, but when on a decent run, when it shifts to 3rd it won't shift back to 4th.
Just covered 140 miles in 3rd, kills the fuel consumption and I had to upset all the truckers when keeping the rpm down to a sensible level (around 55 mph!)! |
|
Back to top |
|
|
Google Sponsor
|
Posted: Fri Jul 29, 2022 13:05 Post subject: Google Ads keep this community free to join! |
|
|
|
|
Back to top |
|
|
Doglet
Joined: 04 Jun 2022 Posts: 49 Location: Wantage
|
Posted: Sun Aug 21, 2022 20:50 Post subject: |
|
|
Must admit I am a tad surprised. 75 views, not one response. As a new chap on this owners club, I have to confess I am disappointed. |
|
Back to top |
|
|
Lewis Site Admin
Joined: 25 May 2006 Posts: 16291 Location: Huddersfield
|
Posted: Mon Aug 22, 2022 9:49 Post subject: |
|
|
The problem is not the club. it is the vehicle.
Advice is only forthcoming from other members, who have the same vehicle. There are few members with a V6 and even fewer of those who have the mechanical knowlege to answer your problem. _________________
Copyright is retained for all my photos. Please don't copy them without asking permission
Do not blindly go where the path may lead you. Go where there is no path and leave a trail that others may follow!
ルイス |
|
Back to top |
|
|
andyman
Joined: 08 Dec 2012 Posts: 5601 Location: Penrith
|
Posted: Mon Aug 22, 2022 16:01 Post subject: |
|
|
Where 2.8TDs have had this problem, IIRC sometimes it is a temp sensor issue, as top gear selection is inhibited until the engine is warm. The issue can be triggered by a low coolant level not touching the sensor. _________________ Andy C L300 Super Exceed - over 100 smiles per gallon! |
|
Back to top |
|
|
Lewis Site Admin
Joined: 25 May 2006 Posts: 16291 Location: Huddersfield
|
Posted: Mon Aug 22, 2022 18:47 Post subject: |
|
|
Andy That is in relation to O/D not working until the engine / transmission is at normal working temp.
Note Doglets last line, in his first post, indicates the engine/ transmission will have been at normal working temp for over 100 miles. _________________
Copyright is retained for all my photos. Please don't copy them without asking permission
Do not blindly go where the path may lead you. Go where there is no path and leave a trail that others may follow!
ルイス |
|
Back to top |
|
|
andyman
Joined: 08 Dec 2012 Posts: 5601 Location: Penrith
|
Posted: Tue Aug 23, 2022 14:11 Post subject: |
|
|
Ah, but how does the transmission "know" that it has reached working temperature? Does the ecu need a permanent signal from sensor(s) to maintain O/D engagement? Another possibility - overheating O/D solenoid coil? I'm assuming it has to be energised to maintain O/D, rather than the opposite? Curious that O/D works when cooled off. If the actuating mechanism is a bit stiff, there could be enough return spring pressure to ensure disengagement, but increased resistance in the solenoid coil windings due to heat, might be enough to prevent actuation/engagement of O/D?
I'm grasping at straws here, never had an issue with the L300's O/D.
Any thoughts from our resident electrical/electronics experts? _________________ Andy C L300 Super Exceed - over 100 smiles per gallon! |
|
Back to top |
|
|
|