Auto holding onto too high a gear

benm · 10-30-2009, 07:28 AM

I have a 53 s320cdi. I have noticed that the gearbox is reluctant to change down from top gear even when the revs are as low as 1000rpm. This can cause the car to judder especially under load going up a slight rise.

I changed the atf and filter and this has helped however the gearbox is still reluctant to change down. On a long journey of more than an hour the problem sometimes gets worse where it will hold onto the lower gears as well and refuse to chage down or kickdown unless manually done. When this is happening stopping and restarting the car does help.

Even from the cold the kickdown seems more hesitant compared to previously. Driving a 220cdi with the same gearbox it will quickly drop down a gear to prevent the engine straining at low revs.

I am suspecting it may be either the MAF sensor or the gearbox speed sensor plate. Is there any easy way to test these?

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benm · 10-30-2009, 08:43 AM

Noticably worse this morning even from cold.
Engine sounds odd, changes up gear far too soon and really slow!

benm · 11-07-2009, 01:50 PM

Disconnected MAF sensor and now running a lot better.
Will get a new one fitted this weekend.

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10-30-2009, 08:43 AM	#2
benm Newbie Join Date: Jul 2009 Posts: 11 Drives: s320cdi 420se e220cdi	Noticably worse this morning even from cold. Engine sounds odd, changes up gear far too soon and really slow!

11-07-2009, 01:50 PM	#3
benm Newbie Join Date: Jul 2009 Posts: 11 Drives: s320cdi 420se e220cdi	Disconnected MAF sensor and now running a lot better. Will get a new one fitted this weekend.

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