Greg530

See the attached pic. There is an automatic rev limiter on diesels (don't know how it is on gas/petrol versions). Those little marks, between 4500-5000 on the picture automatically move as the engine gets warmer. At cold start they are at about 4000.
However I never see them completely disappear no matter how warm the engine is. The position as you see on the picture is where they always are at normal operating temperature.
Is that normal?

thanks
Greg

pgroen

Mine never disappears either - apparently that's normal behaviour;

have a look at this thread:
http://forums.e60.net/index.php?showtopic=26281

By the way, have anyone noticed if the limit is 'fixed' or the limit actually changes with the engine temperature ?

AlwynMike

I would imagine that the limiter is set at 5000rpm whatever the engine temerature. The moving marks designate the "warning" zone that should only be used intermittently. I've never had my engine up there to see if the limiter works or not - unlike petrol engines, there is no advantage in revving to the redline. I seem to get the best performance by changing up at 4200 or thereabouts, and I've never had the opportunity to try those sort of revs in top gear yet, although I hope to at some stage - if only to see if the 155mph limiter is fitted!
If anyone tries out the limiter on a cold engine, remind me never to buy a car from them. Mechanical sympathy and all that.

cidair

My limit never seems to move at all! Maybe it?s stuck?

What engine do you have? Mine is the 3.0 single turbo.

aybeesea

Well put.

The temperature gauge marks aren't exclusive to Diesel engines AFAIK.

ABC

525iSE

I don't think thats the limiter. Its actually the engine temperature, you can rev over there. I have a petrol car, and that is just the temperature gauge, not limiter. Some others might be able to explain it better than me. Regards.

cidair

The rev limit is actually electronically controlled and cuts the fuel when you rev over the maximum permissible limit.

BTW - called my dealer today and asked about my automatic ( moving 7 not moving ) scale on the revcounter.
He didn?t know if it was supposed to move or not excellent...............

Can anyone clarify this please

E60Sim

cidair:

When you start your car up, and the engine is cold, the max revs on our 530d is 4000 rpm's. After 5-7 min, the revcounter with the "limit" is the same as in the picture.

But when the "limit" moves from 4000-4600 rpm's it's still not good for the engine if you kick it, because the engine is still cold. The water temprature is only 70C, or like the temp gauge below!

So when the "limit" moves from 4000-4600 the engine is still cold, and therefore it's best to wait for at least 10 min. before racing.

cidair

This is very strange! On my car the redline is ALWAYS 4750rpm, even when the engine is cold! The dashed area starts at 4250rpm.
I have never tried where the electronics cut out the engine though.
My rev counter scale looks exactly as in the picture in the first post

aybeesea

Exactly.

In fact AFAIK (I've not been up there), the limit is neither the start of the gradations nor is it the start of the red section.

The gradations are advisory and reduce (in my car) from "quite a few" to about 4 visible when the engine is at operating temperature.

ABC