JDWilson

I've owned my 1990, 500SL since September but never took it above 4400 rpm's until a week ago. The car pulled flawlessly until I hit around 4950 rpm's and then it jerked like a bucking horse. I suspected that it had hit the rev limiter but all the info that I can find shows that the car makes it max horsepower at 5700 rpm and the tach shows the red line at 6000 rpm. I took it to my Mercedes mechanic who has been working on Mercedes vehicles for over 30 years and he said that I DID hit the rev limiter. I told him that I was only at 4950 rpm when it kicked in and he said that although the tach says the red line is much higher, the factory set the red line to kick in long before the driver would over-rev the engine and cause damage. I have owned a lot of cars (Mercedes, BMW, Jaguar, Porsche, etc) but have never owned a car where the rev limiter would kick in way below the indicated red-line on the tach.
*My questions are:
(1) has anyone else experienced this?
(2) Does anyone have the same engine (M119 engine/5.0 liter/322 hp) and their engine revs higher than 4950 rpm with out the rev limiter kicking in?

ChrisB

I googled your words and found this link

https://www.benzworld.org/threads/19...0-rpm.3020006/

It looks like others have fixed the issue.

JDWilson

ChrisB: Thanks!! I'll check my car next week.

GuilhermeRocha

Hey there! Did you find your problem? I am the owner of the 500SL that was mentioned before and I still have the problem!

JDWilson

****PROBLEM SOLVED! Turns out that someone changed out the MAS Control Module on my car to an incorrect model. The MAS module on my car was for a M103, 6 cylinder engine. This was causing my engine to hit the rev limiter at 4950 rpm and causing the car to be hard to start after the engine had warmed up. I bought the correct MAS control module (used) on Ebay and the two problems have totally disappeared.