Rev Limiter - PeachParts Mercedes-Benz Forum

derryb · #1 11-12-2005, 11:24 AM

Should my rev limiter be kicking in and causing the car to momentarily stop getting fuel when i go into passing gear and hold the pedal to the floor. Just had a valve job (very reputable mechanic, car runs great), and my mechanic tells me this rev limiter thing is normal. Should a properly running automatic 560 SL ever see the rev limiter kick in under maxium fuel demand while on the road? I can understand the value of this feature while in park and over-revving the engine, but I would think that if an engine is running properly and a tranny is shifting properly the rev limiter would never need to kick in (unless of course you were doing 200+ mph and still had it to the floor). Mechanic did try a new fuel pump relay just to prove his point, same results.

dkveuro · #2 11-12-2005, 12:19 PM

At what RPM isthis limiter cutting in ?

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derryb · #3 11-12-2005, 03:39 PM

5000 to 5500 as designed, but i guess my real question is: should the tranny shift before this point? It only happens when i really get down on it and hold it. Should a 560 ever see the rev limiter cut in during driving no matter how extreme the acceleration demand?

Ralph69220d · #4 11-12-2005, 04:15 PM

I'm just guessing, but with an auto trans there is always going to be slippage in the torque converter (in effect, going from 1st to 2nd, etc, there is a point where there is torque converter slippage) so the rev limiter could kick in. I would think one thing to determine is whether at full throttle, at what point in rpm's is the transmission going into its shift phase. Just my opinion.

t walgamuth · #5 11-12-2005, 04:59 PM

your tranny is not shifting soon enough. it should shift just below the redline or right at it. if redline is 5500 i would expect it to shift there.

tom w

dkveuro · #6 11-13-2005, 03:04 PM

In 'D' the trans' should upshift at WOT before hitting the rpm limit.
The ONLY time the limit should cut in is if you select other positions ie : 1/2/S/N...etc. and possibly R !!!!! Although personally I've never tried to run backwards in 'R' to find out.....someone here, no doubt has !

Either the trans is faulty or adjustment has been upset...check with last tech you saw, and ask him/they to check operation of trans' shift points.

Seem to think that factory rpm limit on your engine is higher than 5500.rpm.( ?)

#7 11-13-2005, 03:47 PM

it is possible that the bowden cable is too tight, try adjusting that first,

derryb · #8 11-13-2005, 08:11 PM

bowden cable on a 560sl? where is it, how to adjust?

derryb · #9 12-06-2005, 11:35 AM

Red line is 6000, rev limiter cutting in at 5000. What determines the rev limiter set point? Also if i adjust the tranny shift cable for a quicker shift point do I want a longer or shorter cable?

duxthe1 · #10 12-06-2005, 09:33 PM

The fuel pump relay determines the fuel cutoff point. If you look at the relay it will have the cutout printed on it. eg 5500 min

derryb · #11 12-10-2005, 10:12 PM

yup, its cutting out when it should, looks like its not shifting soon enought. adust cable longer or shorter for quicker shift?

derryb · #12 12-13-2005, 06:31 PM

adjusted cable (rear of intake, simple nutdriver adjustment) for quicker shift. Shifting like it should, when it should with no rev limiter kicking in. Thanx.