SL55/63/65/R230 AMG: I/C pump going out?
So some info: runs great around town, half or quarter throttle pins you in the seat. At the track I noticed right around the top of second gear and into third gear (about 80mph) you can feel the power noticeably drop. I even put some 104 octane unleaded race fuel in it after the first run to make sure it wasn't detonating. On the trip home after driving along for about 5 minutes it would pull much harder in the 80mph or so range to 100 with ease. It felt like a totally different car from a 40mph punch. No check engine lights and it idles and runs perfectly smooth at partial throttle. I have warranty so can the dealer figure this out without an error code? Engine temps are at about 100C. Thanks for any input.



Either the pump is a gonner, or you have air pockets!
What acctually makes one uncertain if there really is a failure or not at times, is that the immediate punch when you throttle it, still feels pretty good..!
But the IAT builds up reeeaally fast, so already in a couple of seconds, you have an SL500...

So get the pump replaced (or the system bled), and you will have a car that PULLS in a veeeery different way..!
And then get it tuned with a little ECU (with the torque curve more horisontal, instead of dropping), and the car just keeeeps pulling ALL THE WAY to red line...
You may or may not be successful getting the dealer to replace it before it fails completely. The local dealer here in Ann Arbor is terrific but wouldn't replace mine before it failed completely.
It's not an expensive part and it's also a DIY project if you're inclined to turn a wrench, so you can have it swapped out even if your dealer won't replace it under warranty.
Good luck!
You may or may not be successful getting the dealer to replace it before it fails completely. The local dealer here in Ann Arbor is terrific but wouldn't replace mine before it failed completely.
It's not an expensive part and it's also a DIY project if you're inclined to turn a wrench, so you can have it swapped out even if your dealer won't replace it under warranty.
Good luck!
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I bought CM30, but I've also heard that CM50 is even better, but is a bit bigger, and takes therefor a few mods to make it fit...
I had a similar problem with my CL65, and then they phoned me and told me
there was a recall, apparently sometimes they de-laminate and cause
an obstruction. Might be worth a try cos my car got noticeably slower
when used hard.
Some other details on the invoice were that the "pressure sensor downstream in the intake faulty - SDS test code P20E1 and P2007 pressure sensor downstream faulty replace sensor in intake and 2 sensors for air box"
Also under cause it lists:
541011 short test, perform
2 005-153-50-28 sender unit (thinking these are the air box sensors)
1 005-153-72-28 sender unit (intake)
152177 Knock sensor, rear right cyl head -
ignition system, R&R
So I'm also guessing they replaced a knock sensor.
Anyway, I just wanted to put info in the thread in case it helps anyone else down the road.
Yeah, those temps are way too high. Hope you are able to sort it out without too much more work!
Last edited by the head; Oct 28, 2010 at 05:00 PM.
Would it be normal for a pump to go out with only 16,000 miles on it?
Where is the pump located, how much of a DIY project is changing it out?


