CLK430 rev limited when in park and neutral?

[CLK430NEWB]

Hi Guys and Gals

My CLK430 project - I've only driven it for 10 miles and it is now SORN

I've had it running on the driveway for oil change etc. Have noticed it seems limited at 4K when revving it (fully hot of course).
I didn't gun it on the drive home from collecting it.

This normal?

 

[daveenty]

Perfectly normal.

Based on the theory that you don't need to rev over that when not moving.

 

[CLK430NEWB]

Thanks. Panicked a little.

I need to buy an OBD2 reader too as I've the MIL light on.
Any suggestions of a good cheap one on eBay. ?

Cheap as in I've gotta spend loads on getting the body more ferrous than oxide.

Love the car. Gonna be a great project.

 

[clk320x]

yep completely normal, I've tried this also lol

 

[MancMike]

Yeah, it must be the same in all Mercs, it's like that in my M272 engine. Spoils the fun a bit when you're showing off it's noise while stationary... So put it in D and do a brake stand instead.

getting the body more ferrous than oxide.

Clever. Made be chuckle.

 

[stwat]

Revving an engine up high when it is not under load can be very damaging indeed.

 

[MancMike]

I've heard that. Still no idea why... Bikes do it all the time instead of a horn.

 

[clk320x]

Revving an engine up high when it is not under load can be very damaging indeed.

I guess that's why it's limited to 4K?

I tried to see what's the most it'd rev to in Park a few months ago when I didn't know much about autos

I guess this isolated incident didn't cause any damage as I didn't note any change

Also I always see people with V8s /AMGS/ SVRs doing massive rev battles ?

 

[stwat]

Also I always see people with V8s /AMGS/ SVRs doing massive rev battles ?

Indeed. But you don't see the broken engines and the bills that have to be paid by the next owners after the previous owners have offloaded their ****ed up engined cars/bikes to the next unsuspecting owners

 

[MancMike]

I guess that's why it's limited to 4K?

I tried to see what's the most it'd rev to in Park a few months ago when I didn't know much about autos

I guess this isolated incident didn't cause any damage as I didn't note any change

Also I always see people with V8s /AMGS/ SVRs doing massive rev battles ?

Mate I've had my car for over 3 years and have maxed it's revs in park loads of times. It causes no damage. That's why the limit is there. Whatever redlining it under no load does, it's unable to do, due to the limit.

Those doing standstill revving, just aren't taking it that high.

 

[CLK430NEWB]

They do it in Fast and Furious without any issues!

 

[crisc204]

They do it in Fast and Furious without any issues!
��

lol
they also go through 10-20 of each character car per film
youtube search "Lambo fire LONDON" and youll see where revving the nuts off a stationary super car gets you...

The manufacturer assumes high revs means high airflow over through rads and intercoolers.
All the sums are done based on that.
The other thing is mismatching high revs on a stationary Auto and selecting drive will break something after you hear a massive clonk and lurch forward several feet...


Again this no load revving does wipe miles off the service life of some components buts its more the intentional raising of EGT's to make it pop and bang that can cause issues
through heat build up and then heat soak if the engines red hot and then switched off
Listening to your V8 exhaust note now and again while parked wont do much if any damage
Sustained high revs... rev pop bang pop rev nonsense while parked will damage the car eventually

 

[Revvd]

My track/drift car only gets driven on the rev limiter (which incidentally has been raised above standard). To the extent that the manifolds and downpipes are actually glowing bright orange by the end of it. Done this for years and years, and its been fine. Never rebuilt, never died. Bought a backup engine for when this one does go pop... its sat gathering dust for years and probably seized now and in a worse state than the one in the car!

 

[CLK430NEWB]

I will never believe anything I see on Fast and Furious EVER again!

All jokes aside, I appreciate knowing it is limited.

 

[PobodY]

My track/drift car only gets driven on the rev limiter (which incidentally has been raised above standard). To the extent that the manifolds and downpipes are actually glowing bright orange by the end of it.

I get the manifold and downpipe glowing in the Nissan all the time; so much so that until the first muffler the stainless has gone blue, and after that it's golden.
It does have a lower limiter when there's no engine load, but it still pops and bangs at 5k; you don't need to hit the redline on the motor.

Perhaps Mercedes just think it's not a very refined thing for owners to be doing, so limit it.

 

[DSM10000]

I've heard that. Still no idea why... Bikes do it all the time instead of a horn.

It is quite simple, it is the rapid rate of change in load on components such as bearings , con rods etc that will eventually cause damage

When the car is driven the change in engine speed and therefore load is much less.

Motorcycle engine components generally have lower internal mass and therefore lower inertia.

 

[baxlin]

Forgive a reminiscence, but this thread reminded me of an automatic Triumph scooter I had in my youth.

No clutch, just turn and go. There was a microswitch in the seat padding, so that it could only be revved (and therefore go!) if you were sat on the seat.

Unless of course you were working on the bike, with the engine running and throttle open, and leaned across the seat to pick up a spanner. Then it would move, and it did......