Clunky Changes/Stuck In Gear When Warm

[KillerHERTZ]

Been having issues with the C220 CDI (S203) once its upto temp. - I believe its the: 722.699
Gear changes become clunky and occasionally it gets stuck in 2nd. As soon as its cooled down again it runs fine. I have scanned it with both iCarSoft and Xentry which didnt flag a single code.

Looking at the bottom conductor plate, it looks extremely oily, could it just be a case that it needs a full clean down/fluid change? Anyone have any other ideas what it could be?

Cheers!

 

[Bigdrew]

Been having issues with the C220 CDI (S203) once its upto temp. - I believe its the: 722.699
Gear changes become clunky and occasionally it gets stuck in 2nd. As soon as its cooled down again it runs fine. I have scanned it with both iCarSoft and Xentry which didnt flag a single code.

Looking at the bottom conductor plate, it looks extremely oily, could it just be a case that it needs a full clean down/fluid change? Anyone have any other ideas what it could be?

Cheers!

Hi is this the trans plate your talking about

 

[gurpz]

I would suggest a full gearbox fluid and filter service first including replacement of the electrical plug connector known as the pilot bushing. If the connector plug is wet go and clean out the TCU in the passenger footwell also as its likely filled up with gearbox oil caused by the pilot bushing leaking.

 

[KillerHERTZ]

So the car, now fully legal with a working starter is stuck in 1st/2nd gear. I have it booked in next week for a fluid change however they arent gearbox spealists and suggested I call up one locally.

Spoke to the guy who said if its stuck in 2nd, then its lost compression already/gearbox oil is burnt and its game over for it - sell the car. £2-2500 for a rebuild.

He, obviously the expert and im not, but is it still even worth getting a flush? or is it more money down the drain. - Ive made a **** up, took a punt on a project and now have a 1.7 paperweight

I could look at getting a replacement `gearbox, however I believe these still need to be coded to the car - unless I get an indentical spec one + he said make sure I get the convertor also.

Thoughts?

 

[Bellow]

Oil analysis will tell you the condition of the oil - and anything floating in it - metallic or friction surface particles.
Do you mean 'pressure' where you say compression? If so, is there not an external test port to measure pressure at?
Attending to those would confirm/deny your specialist's opinions with facts.

 

[KillerHERTZ]

Oil analysis will tell you the condition of the oil - and anything floating in it - metallic or friction surface particles.
Do you mean 'pressure' where you say compression? If so, is there not an external test port to measure pressure at?
Attending to those would confirm/deny your specialist's opinion with facts.

I think im still going to go ahead with getting it flushed - I have bought the kit already and as you say, ill be able to see the condition of the oil afterwards.

Im sure he said "if its stuck in 2nd, it will have already lost compression" - I may have misheard him however

 

[Bellow]

I think im still going to go ahead with getting it flushed - I have bought the kit already and as you say, ill be able to see the condition of the oil afterwards.

Not in the required detail. The 'burned oil' scenario should be apparent at the dipstick (I assume there is one or that a tube for one is present that oil can be drawn from) by the darkness of the fluid and smell.
I'm more cynical than believe a mere change of fluid will recover the missing gears. Analysis before remedy.

Im sure he said "if its stuck in 2nd, it will have already lost compression" - I may have misheard him however

It can only be pressure he is referring to. Line pressure is a crucial aspect of auto trans operation and is constantly varied under differing operating conditions. Too low and slippage will occur. Getting a number on it would be advantageous (can it be read via the OBD port on a scanner app?). Something as simple as a blocked filter can kill pressure. A failing pump too - but likely there would be wear metals in the oil. A stuck valve could bleed off pressure (which dirty - by analysis - oil would suggest) and could be a cheap change of valve to remedy.

 

[KillerHERTZ]

Thanks for the replies.

Ive had it on my knock off Xentry and not a single error is appearing + on iCarsoft Max. - Xentry, even though its knock off has never failed to read a code since ive had it...

Ill try and have a look at the dipstick which is at the back of the engine.

 

[Trickythemerc]

Brown ATF is a sign of burnt clutch material. I can't remember ever seeing a flush doing much good if the clutch packs are worn. Rebuild is the answer.

 

[Will]

Before you get too deep into this, have you checked the fluid level?

 

[KillerHERTZ]

Before you get too deep into this, have you checked the fluid level?

I have a feeling it is low. The undertray and the conductor plate is wet and has been leaking for god knows how long.

It's booked in for next week to have it flushed. Already paid for the kit so might aswell/gaskets etc
It will confirm if the oil is burnt or has filings in it.

 

[Bellow]

It will confirm if the oil is burnt or has filings in it.

And coolant?
Hold plenty back in case a full analysis is beneficial. Shy of that, there's an ad-hoc test for water/coolant, and some oil on clean kitchen towel should show any glitter (if that bad) and how dark it is and smell should indicate if its been thermally stressed. I'd expect clutch/brake wear to be evident in the filter so have it put aside for inspection if necessary.