7G Torque Converter issue P1843 Torque converter lockup clutch (KUeB) Y3/7y4

[WonkyWombat]

Hey all - I have an issue with my car and looking for some advice.

W204 2011 SPORT C250 CDI (Facelift model) 7g - 108k miles

Gearbox has been serviced every 30k - It's been about 30k since the last time so it is due.

P1843 Torque converter lockup clutch (KUeB) Y3/7y4

There may have been another error but I can't remember I'm afraid.

The issue:

Sunday:

On sunday, went for a drive, was cold. It felt as if gears were "snatching" and "holding" revs whilst driving, it wouldn't change when needed - thought this may have been DPF due to it being cold.

However, the biggest issue came when i went from 2nd > 1st coming to stop, the car snatched gear 1, and felt an abrupt gear change.

Fast forward 1 day (Monday)

Book the car in the garage (merc specalist) they banged it on STAR and it came back with the error:

P1843 Torque converter lockup clutch (KUeB) Y3/7y4

They mentioned STAR tells them to rip out the torque converter, and change it. However, driving there, it felt fine. Literally no issue at all. The gears changed when needed at slow speeds + faster speeds, and you wouldn't have known there was a problem.

Then in the evening, I needed to pop out, and my car felt quite normal, maybe a bit sluggish which I put down to the cold, I drove about 4 miles, and the car went into limp mode. No EML, warning lights etc.

Pulled over, turned car off, turned it back on and went back to normal without limp mode I then nursed the car slowly home, pulled up, and have left it.

My options are:

New torque converter = £1800-£2300 (ish)
Refurb my old one at a local auto specialist (£850)
Get ATF fluid change (£240) and hope this fixes it.

Has anyone came across any similar issues, and any advice as to if you think it is the torque converter, or maybe lack of oil/bad oil? Or any other advice?

Is it possible to replace just the torque converter, or is it advised to replace gearbox too?

 

[LostKiwi]

Torque converter lock up clutch issues are not all that uncommon.
TC replacement is the way.
If you search the forum there's a few threads on it.

 

[WonkyWombat]

Torque converter lock up clutch issues are not all that uncommon.
TC replacement is the way.
If you search the forum there's a few threads on it.

Thanks, so is it not to due to fluid issues?

I have had a look on the forums, but there seems to be a lot of yes it's this no it's this, - with people having diffenerent remedies to them.

Can I replace just the TC (and not need to worry about the gearbox? or may the gearbox be afffected too?

 

[LostKiwi]

TC only. No need to do the gearbox.

 

[WonkyWombat]

TC only. No need to do the gearbox.

Thanks - is there any chance this error could be related to the fluid levels? I'm not sure if i do risk it for £240 - or do I just go all out and get it replaced/refurbed.

 

[LostKiwi]

Low oil causes slipping and loss of drive. By all means get it checked but I'd doubt it's the issue.

As a thought - how many miles and when was the gearbox last serviced?

 

[WonkyWombat]

Low oil causes slipping and loss of drive. By all means get it checked but I'd doubt it's the issue.

As a thought - how many miles and when was the gearbox last serviced?

No worries - I haven't lost drive, mainly holds gears for longer, and sunday was bad when it was grabbing gears.

I was "hoping" it could have been because sunday was cold, the ATF wasn't working as well, whilst when i drove it to the garage it warmed up, and was better, but then obviously i had limp mode so a service would have surficed.

Would the TC issue be intermitent? Is there anyway to test/symptoms wise in the car to pinpoint it is the TC?

I'd rather not just *urine* £240 up the wall, when it's most likely going to be a replacement job anyway - but I also don't want to replace it, if it's not down to that either. Double ended sword regardless.

I believe it was serviced at around 84k. It's currently on 108k, hasn't really been driven hard, normal motorway speed, generally not driven around town (or avoids). Obviously now and then I put the foot down, but I generally drive within th speed limit.

If it helps, the car was sat for a week before it all happened.

 

[00slk]

If the TC is locking up it can cause very fine metal filings to contaminate the fluid, if this is the case it could damage the transmission.
Ask me how I know
My 211 would be as you described how ever once warmed up was if no issues at all.

 

[WonkyWombat]

If the TC is locking up it can cause very fine metal filings to contaminate the fluid, if this is the case it could damage the transmission.
Ask me how I know
My 211 would be as you described how ever once warmed up was if no issues at all.

Doesn't sound ideal... I assume the 211 is what you refer to ref to metal filings?

 

[00slk]

Doesn't sound ideal... I assume the 211 is what you refer to ref to metal filings?

s211 is the model number of the 320cdi Mercedes I have, had pretty much the same issues you have, in the end took the car to my Mercedes man who put it on Star and reported back TC. He said to replace it along with the transmission because the fine metal filings would have flowed through the entire system. But I only replaced the TC and 900mls later what contaminated fluid was inside the transmission went through the new second hand TC and now I am back to square one I have another TC and transmission to go in when I get a chance.
My model is the 5 speed auto so may be different to your 7 speed.
Oh and also flush out the transmission oil cooler

 

[WonkyWombat]

s211 is the model number of the 320cdi Mercedes I have, had pretty much the same issues you have, in the end took the car to my Mercedes man who put it on Star and reported back TC. He said to replace it along with the transmission because the fine metal filings would have flowed through the entire system. But I only replaced the TC and 900mls later what contaminated fluid was inside the transmission went through the new second hand TC and now I am back to square one I have another TC and transmission to go in when I get a chance.
My model is the 5 speed auto so may be different to your 7 speed.
Oh and also flush out the transmission oil cooler

Ahh that's not good at all. Sorry about that. Just out of interest, wouldn't a proper flush have cleared the box out of any filings? I could be wrong, but I'd have thought that would have sorted that from coming back

 

[00slk]

Ahh that's not good at all. Sorry about that. Just out of interest, wouldn't a proper flush have cleared the box out of any filings? I could be wrong, but I'd have thought that would have sorted that from coming back

My bad I'm afraid.....Yes I think a complete flush of transmission and oil cooler would have been appropriate.
It all depends too on how long the car was driven like it, with mine it has done over 4000 miles, and goodness knows how many miles it had done with a faulty TC before I bought it, thought it strange that the car was warm when I test drove it. Told it was because I was using it said the seller, and being a Mercedes specialist I believed him

 

[Gazwould]

Hey all - I have an issue with my car and looking for some advice.

W204 2011 SPORT C250 CDI (Facelift model) 7g - 108k miles

Gearbox has been serviced every 30k - It's been about 30k since the last time so it is due.

This facelift 2011 W204 250 CDI has the 7g+ automatic gearbox which the ATF interval is every 5 years or 75,500 miles , if the interval and gearbox is confussed is the ATF fluid ?

 

[WonkyWombat]

This facelift 2011 W204 250 CDI has the 7g+ automatic gearbox which the ATF interval is every 5 years or 75,500 miles , if the interval and gearbox is confussed is the ATF fluid ?

I've always been under the impression it's been 30k (The W204 facebook group all says 30k) - not too sure what you mean about the latter sorry?

 

[Gazwould]

Listen to the people here...

Red 236.14 Vs Blue 236.15 .

I have the same Merc and I telephoned 2 main dealers and 2 independents and they all came back with the same answer .

 

[WonkyWombat]

Listen to the people here...

Red 236.14 Vs Blue 236.15 .

I have the same Merc and I telephoned 2 main dealers and 2 independents and they all came back with the same answer .

Ahh, so you think the wrong fluid has been put in?

 

[Gazwould]

Not necessarily , but worth checking .

 

[LostKiwi]

Is yours 7G or 7G+?
.14 is for 7G and .15 is for 7G+

 

[WonkyWombat]

Is yours 7G or 7G+?
.14 is for 7G and .15 is for 7G+

7G+ (I think, as it has stop start) just spoke to an auto specalist, and they suggest wrong fluid too so have advised to carry on with fluid change at my merc specialist, and any issues to bring it to them to refurb TC.

1K for them to drop the torque converter, and refurb, then put back on. They also mentioned they uprate all the gibbins, plates etc. 12 months warranty on labour and TC.

 

[LostKiwi]

A few on here have used JPAT for torque converters. JPAT seem to have a decent reputation too.