Auto only rev to 3.5k in park?

Born_2_Kill_83 · 21 Dec 2007 at 11:20

I noticed when being a bit of a noob this morning and revving my XJR (I would like to point out this isnt cool in a grandad car) when parked it wouldnt revv past 3500 RPM. Is this normal? Somthing to do with autos perhaps?

chrislusty · 21 Dec 2007 at 11:22

Autos are limited to lower rpm when in P or N, so sounds ok, check the handbook if your unsure though.

Scania · 21 Dec 2007 at 13:14

Loowi_ashley said:
I noticed when being a bit of a noob this morning and revving my XJR (I would like to point out this isnt cool in a grandad car) when parked it wouldnt revv past 3500 RPM. Is this normal? Somthing to do with autos perhaps?

I recall my old BMW doing this, it wouldn't rev past 4200rpm - turned out one of the cats had collapsed.

Reving an Auto in P or N is iirc, very bad for the transmission, don't do it - Grandad.

Clarkey · 21 Dec 2007 at 13:18

It's nothing to do with the transmission, and neither will it damage it. Plenty of modern cars limit rpm in neutral whether auto or manual, it's to stop you being a hooligan.

dalin80 · 21 Dec 2007 at 13:19

a few cars do this, even old mercs had a 'you're not moving moron' rev limiter

Scania · 21 Dec 2007 at 13:27

Clarkey said:
It's nothing to do with the transmission, and neither will it damage it. Plenty of modern cars limit rpm in neutral whether auto or manual, it's to stop you being a hooligan.

The manual of my old e38 clearly warns against such actions , and, fwiw, it had no such rev limit in P or N, it would quite happily red line if you were inclined to do so!

ajgoodfellow · 21 Dec 2007 at 13:52

I thought when you put it into Park it would stop the gearbox from moving? Therefore you'd wreck the gearbox if you put it into Park when moving or revved it when in Park?

Clarkey · 21 Dec 2007 at 13:57

It's only the output shaft that is locked in park, otherwise it's just like being in neutral.

ajgoodfellow · 21 Dec 2007 at 14:01

Ah - shows how much I know about autos!

Thanks

OllyM · 21 Dec 2007 at 14:12

Jez's S-class does the same, so I assume it's 'normal'

Jez · 21 Dec 2007 at 14:51

Definately normal on the S-class, it even mentions it in the manual

Third Opinion · 21 Dec 2007 at 16:56

I was told when i worked for volvo that you should never rev an auto in park as it wrecks the torque convertor.

Might be rubbish thaough and it was a long time ago so auto's have probably improved.

helpimcrap · 21 Dec 2007 at 17:01

Third Opinion said:
I was told when i worked for volvo that you should never rev an auto in park as it wrecks the torque convertor.

Might be rubbish thaough and it was a long time ago so auto's have probably improved.

not if you read about the stuff about mk3 mondeo autos.