AMck
Senior Member
- Joined
- Jul 3, 2008
- Messages
- 848
- Reaction score
- 15
- Location
- Newport
- Your Mercedes
- 2007 E320cdi S211, SL320 2000(written off), Lotus Excel
Hi. Well I have been trying to sort out harsh gear changes on my 2000 SL320 for a little while now - so any help would be appreciated.
Sorry if this is a little long, but just want to try to get everything relevant down.
The symptoms
The harsh changes are not constant - it can also give some lovely smooth changes. The worst changes are usually on light throttle or on overrun when changing up.
eg when crawling in traffic or after accelerating up to say 30 or 40 mph and then lifting off the throttle.
Also occassional hard changes down when slowing for junction etc.
On heavier accelleration it will sometimes seem to change gear, the revs will rise a little and then drop back to where they were before about a second later actually change gear.
kick down was very poor with quite a bit of hesitation
Work to date
Replaced ATF (4 liters) and filter - no real change
codes read and code present -
116 Component Y3/6b1 (transmission oil temperature sensor) or
component Y3/6s1 (starter lockout contact) is sporadically
faulty or both
Also the data was read for the adaption values (sorry don't have these). the values were in 2 columns and the left figures were around 140 and the right column around -40. Informed these should be much closer.
The 116 code when cleared comes back.
code cleared and adaptive values reset - no change
Following advice I pulled the hydraulic block and electroplate and sent them to Technical Automatic Services who bench tested them and found no faults.
They re-calibrated the unit and returned it. Refitted with another 5 liters of ATF, new filter and pilot bush (no signs of atf in old one). Codes cleared and adaptive values reset.
This did produce some changes - kick down quicker and smoother, some gear changes a little smoother, but the harsh changes are the same.
Code 116 also returned.
I did notice just before sending electro-hydraulic unit off some very slight droning, but thought this might just be resonance from the exhaust.
Not so sure now - it is like the noise you get when driving over the non skid surfaces near crossings. Only happens on light throttle at about 1300rpm. So noticable in 4th at around 30mph and 5th at 40mph. By just, either very slightly depressing or releasing the throttle the noise will go.
Did a stall test and the engine will rev to 2500 rpm, from what I have read this should be closer to 1800.
I have bought a new electroplate to fit, but now wondering if this could be a TC fault?
Any thoughts would be welcome
Thanks
Sorry if this is a little long, but just want to try to get everything relevant down.
The symptoms
The harsh changes are not constant - it can also give some lovely smooth changes. The worst changes are usually on light throttle or on overrun when changing up.
eg when crawling in traffic or after accelerating up to say 30 or 40 mph and then lifting off the throttle.
Also occassional hard changes down when slowing for junction etc.
On heavier accelleration it will sometimes seem to change gear, the revs will rise a little and then drop back to where they were before about a second later actually change gear.
kick down was very poor with quite a bit of hesitation
Work to date
Replaced ATF (4 liters) and filter - no real change
codes read and code present -
116 Component Y3/6b1 (transmission oil temperature sensor) or
component Y3/6s1 (starter lockout contact) is sporadically
faulty or both
Also the data was read for the adaption values (sorry don't have these). the values were in 2 columns and the left figures were around 140 and the right column around -40. Informed these should be much closer.
The 116 code when cleared comes back.
code cleared and adaptive values reset - no change
Following advice I pulled the hydraulic block and electroplate and sent them to Technical Automatic Services who bench tested them and found no faults.
They re-calibrated the unit and returned it. Refitted with another 5 liters of ATF, new filter and pilot bush (no signs of atf in old one). Codes cleared and adaptive values reset.
This did produce some changes - kick down quicker and smoother, some gear changes a little smoother, but the harsh changes are the same.
Code 116 also returned.
I did notice just before sending electro-hydraulic unit off some very slight droning, but thought this might just be resonance from the exhaust.
Not so sure now - it is like the noise you get when driving over the non skid surfaces near crossings. Only happens on light throttle at about 1300rpm. So noticable in 4th at around 30mph and 5th at 40mph. By just, either very slightly depressing or releasing the throttle the noise will go.
Did a stall test and the engine will rev to 2500 rpm, from what I have read this should be closer to 1800.
I have bought a new electroplate to fit, but now wondering if this could be a TC fault?
Any thoughts would be welcome
Thanks