350 SL trans intermittent trans problem

[LoTu5]

Hi, I have an intermittent transmission problem. Today I'm in stop start traffic and pull away. The trans won't change up and I try to change it manually with no response. I pull over and turn the engine off and leave it for a while, then start the engine up and the problem has cleared. Earlier in the day I am driving through town and the power has tailed off and pulling away is slow. Again if I turn off the engine and leave it for a while and then start it, it's ok. This has happened ON and OFF over the last eight months and I've taken it to two separate garages who have used the diagnostic machine on the trans and the trans says it's ok, fluid level ok.
Any ideas what this can be ? TIA

 

[LoTu5]

The car is 2007 with 70,000 miles.

 

[DSM10000]

What diagnostic machine was used, was it Mercedes Star?

Conductor plate problems can cause your symptoms however it needs checking by someone with the correct diagnostic equipment who knows how to use it.

 

[LoTu5]

What diagnostic machine was used, was it Mercedes Star?

Conductor plate problems can cause your symptoms however it needs checking by someone with the correct diagnostic equipment who knows how to use it.

I'm unable to confirm that as I didn't think to ask the question. One was at a merc garage in Hertfordshire and the other was a one man band in Dartford, who seemed to know what he is doing. Where else would be the best place in Kent/SE London to find someone who could have one to get another look, without being bent over ?

 

[DSM10000]

I'm unable to confirm that as I didn't think to ask the question. One was at a merc garage in Hertfordshire and the other was a one man band in Dartford, who seemed to know what he is doing. Where else would be the best place in Kent/SE London to find someone who could have one to get another look, without being bent over ?

If you can make it to Horndean then I personally recommend here : Mercedes Benz & Smart Specialists | Prestige Car Service | Horndean, Hampshire

Or this garage has had many recommendations on here : Wayne Gates Specializing in Mercedes-Benz Servicing & Repairs

 

[LoTu5]

If you can make it to Horndean then I strongly recommend here : Mercedes Benz & Smart Specialists | Prestige Car Service | Horndean, Hampshire

OK thanks, I'll bear that in mind, but they're about 90 miles from me. I'm hoping to find someone closer.

 

[DSM10000]

OK thanks, I'll bear that in mind, but they're about 90 miles from me. I'm hoping to find someone closer.

I appreciate the distance.

PCS have some E Class courtesy cars Take your significant other and have day out shopping and eating whilst they look at it for you

 

[alabbasi]

I suspect that the speed sensors on your transmission are going bad. They will through a code but you'll need a higher end scanner to read them (Launch, Autel, Snapon or SDS). If your transmission is a 722.9, then the conductor plate is part of the valve body. AFAIK, it's a dealer only part as it needs to be coded to the engine computer

 

[zipdip]

That the problem with the 7 speed auto box in your car,when they start to go wrong,they seem not to throw up faults that are seen when put on a star,it is only when a part actually gives up that you get codes,that said PCS are very good,it could be that the conductor plate just needs cleaning ,if something has gone wrong with the plate,then they can be repaired if that happens it can go straight back into the car without coding but if you have to buy a new plate or a s/h one it will need star coding,the fact you were able to switch the engine off and then when started it was ok suggests it might only need a oil and filter change.

 

[LoTu5]

Update - I went to Dartford transmissions in the end and they diagnosed the fault as a TCU repair. They had a unit on the shelf and the car was taken in on Tuesday and ready for me to pick up on Thursday. Also had a trans fluid and filter change while they were at it. Pleased with their service and comes with warranty.