Power problems with SL55 AMG

[angusdawe]

When I really press on in the car, it gives the full Nascar violence for about 30 seconds, then, Ford Ka.... Almost as if the wastegate is stuck open, or it has dropped into a default get-you-home mode. No indications from the electronics or error messages from the console. Drive sedately for 5 minutes, and you get some performance back, but for a shorter period.

There is also a 'click' noise when I gently press the throttle at low speed that sounds like high pressured air being released, and I think this is new..

Also, the gearbox has clunked badly a few times too under full acceleration, and I wonder if the gremlin lives there? Lost drive completely once joing M42. Had to park up and restart to reset the 'box. Omigawd.

If I can't trace the problem, I'm going to have to replicate the problem with a M-B dealer service man in the car, but he will probably fill his pants!

 

[Arnie]

maybe you can set-up a video camera in the car and record when it happens again; then you'll have the evidence to show the dealer.

In anycase, just about everything in this car is electronically monitored so that a quick check of the error codes stored on the control units should be able to tell the technician what's going wrong. Visit your dealer's service department and give them the story. They may be able to find the cause without replicating the event.

 

[steveperry]

I had similar problems recently with my car, in my case it turned out to be one item, the mass air flow sensor, that was causing all the grief.

Hope you get yours sorted soon, gorgeous car you have there too

S.

 

[dieselman]

I can assure you that ANY dealer tech will be thrilled to be in the passenger seat when you demonstrate the problem,... but you need to be prepared for them taking out for an extended test run to ensure that all is well once it is fixed. :twisted:

 

[maybach]

Ok, there is a concern with the software in the transmission control unit on your car ( 230474 A.M.G only). Take the car to your M.B dealer this is a known concern and should be an easy fix.
Regards
Maybach

P.S
Dieselman,this dealer tech would test drive the car before and after repairs, as I would any car that has a performace related issue.

 

[angusdawe]

No error codes evident, gearbox has had a re-set, engine and throttle have been re-set.

-----No difference. Car goes like a dingbat for 10 -30 seconds, then performs like a lorry.

I think the supercharger pressure relief valve (pop-off or similar) is sticking open. Dealer didn't know what a pop-off valve was....

I've been around the houses on the phone to AMG Germany, The Oxford MB Dealership, MB Milton Keynes etc etc, with promises of calls back, but, you guessed it, nothing!

My £100,000 car is getting whipped by Golf diesels forchrissakes!!

Is there a decent AMG dealer ANYWHERE? Get them to call me!

 

[mezza]

This is unacceptable. You need to rattle the cage bigstyle. Get dirty with the following:

1 Demand a refund / replacement from where you purchased it

2 Threaten going to the press - I have found honest john to be a great help on such matters (email him at letters@honestjohn.co.uk)

3 Generally convey that you will not go away until the problem goes away - and ask for a replacement while they fiddle with it

good luck