Won't change up Hard Acceleration

[cl55 amg]

This is spoiling my fun, can anybody point me in the right direction?

If I put foot to the floor at 40mph, then the car correctly kicks down. But it then revs out to 5000rpm in that gear , then fails to change up then stays at 5000 rpm
then runs rough with a top speed of 50mph.

Stopping the car and simply turning off the ignition then clears the problem (but it will start again next time I hard accelerate. Gentle standard acceleration has no problems. Easing off at 5000rpm sometimes allows the car to change up and perform normally.

 

[whitenemesis]

What 'box mode are you running in?

 

[cl55 amg]

What 'box mode are you running in?

standard ( S )

 

[seymansey]

Just thinking about this over my cuppa, it sounds very much like the hard acceleration is triggering a MAF, or a coilpack issue.

I'll let the experts have the last call on that however. The CL55 even with half a running engine will out run my super slow C240

 

[cl55 amg]

Just thinking about this over my cuppa, it sounds very much like the hard acceleration is triggering a MAF, or a coilpack issue.

I'll let the experts have the last call on that however. The CL55 even with half a running engine will out run my super slow C240

I had the MAF replaced last year, so hopefully not that. Would a coil pack/MAF stop the change up?

 

[Deleted member 37751]

My friend had exactly the same problem on his S-Class, he tried changing the MAF and EGR and it turned out to be something else, something to do with the exhaust but don't quote me on that just yet...

I'll be speaking to him this evening and I'll find out what was the problem.

 

[hanns gruber]

i have a similar issue at the moment with my E430, hard throttle it bounces at 4k but soft throttle is ok. i just had my MAF done but i also have a "CAN COMMUNICATION" & Voltage problem. wonder if it is linked?

 

[cl55 amg]

My friend had exactly the same problem on his S-Class, he tried changing the MAF and EGR and it turned out to be something else, something to do with the exhaust but don't quote me on that just yet...

I'll be speaking to him this evening and I'll find out what was the problem.

Thank you that would be great, maybe O2 sensor?

 

[Deleted member 37751]

Thank you that would be great, maybe O2 sensor?

That might be it....

I'll let you know

 

[SAFC]

Well, I'm no expert but have you had the gearbox oil level checked?
My indy has the tool to do this - you shuffle the gears up and down while parked and with the engine running, stick in the special measuring stick and Bob's Yer Uncle - you get a level.
You don't need to go to Merc and pay lots of money - mine would do this for nowt!!
Good Luck.

 

[cl55 amg]

Well, I'm no expert but have you had the gearbox oil level checked?
My indy has the tool to do this - you shuffle the gears up and down while parked and with the engine running, stick in the special measuring stick and Bob's Yer Uncle - you get a level.
You don't need to go to Merc and pay lots of money - mine would do this for nowt!!
Good Luck.

gear oil is fine mate, checked at service just before christmas.

 

[Deleted member 37751]

Could be the valves in the gearbox need cleaning or a sensor in the gearbox, maybe flywheel.
He says that yours is almost certainly some sort of gearbox problem
He works for Mercedes as a technician and I described your symptoms to him and that is what he suggested pal.

 

[gina2201]

If I recall my brother had this on an older w124. The car would change up nicely if accelerator pressed, any harder acceleration would result in the car being a little jolty. It was the gearbox vacuum hoses (??!!) or something like that - I am not really sure now to be honest but it was only simple-ish!

 

[Dieselman]

Get the codes read as it sounds like the gearbox isn't being told the engine is at maximum revs.
It will be storing a fault.

 

[cl55 amg]

Well its of to Ian's (124 works) on sat so fingers crossed.

 

[BlackC55]

I do think there will be codes logged. I would be interested to see what they are.

 

[cl55 amg]

I do think there will be codes logged. I would be interested to see what they are.

I will ask Ian to confirm them for me, and will update when i get it back. Whats your hunch as you seem very knowledgeable

 

[BlackC55]

TBH I am not sure.

I think it will be gearbox rather than engine related.

My money is on a solenoid on the valve body or a speed sensor. That is a complete guess though! It is very tricky to diagnose such faults without the car infront of me!

 

[biturbo]

I had very similar symptoms with my s600, apparently because i had a bad cat it on hard accerleration it causes the engine to rev and go nowhere, problem with gearbox. google it symptons of bad cat.
I have looked into it and cl55 cl600 s600 s55 etc all have problems withs cats, ceramic cats that fail quiet easyily when unburnt fuel enters them.
I had knackered cats with no warning messages. Go figure.

 

[cl55 amg]

I had very similar symptoms with my s600, apparently because i had a bad cat it on hard accerleration it causes the engine to rev and go nowhere, problem with gearbox. google it symptons of bad cat.
I have looked into it and cl55 cl600 s600 s55 etc all have problems withs cats, ceramic cats that fail quiet easyily when unburnt fuel enters them.
I had knackered cats with no warning messages. Go figure.

Thanks for the info I will check it out. I would of thought the o2 sensor would come up with a error if the cat was faulty? when you say it would go nowhere, do you mean it wouldn't excelerate at all? as mine is fine until 5000rpm then it falters.

Thanks