ML 270 manifold

[stuart o]

Hi there - see a lot of threads re exh manifold - either realting to seal rings or 'flaps' - the seal side of it is OK but the 'flaps' are confusing me !!
What is the purpose of these and why do they affect performance
I haven't actually got an ML yet but plan to view some later this month and want to be 'genned up' as much as poss beforehand..

Looking at a 2004 and another 2005 CDI - 1 private and 1 at an independant trader in Scotland, both seem to want top dollar also, are these things starting to appreciate

Thanks

Stuart

 

[Ellsy Tanners]

Hello stuart,
The flaps people are mentioning could be the switch over flaps under the manifold which control the varriable intake for the inlet manifold. These open or close as the engine speed increase and the air requirements change for the engine to keep it at the opitmum level.

They have been known to become stiff, and then the actuator arm breaks off at the motor or flaps which can cause problems with lack of power etc. If this happens they are a pig to get at and repair, sometimes require a complete new manifold.

However is not a overly common fault so i wouldn't let it influence your decesion whether or not to buy.

hope thats some help to you

 

[kebo57]

Hi there - see a lot of threads re exh manifold - either realting to seal rings or 'flaps' - the seal side of it is OK but the 'flaps' are confusing me !!
What is the purpose of these and why do they affect performance
I haven't actually got an ML yet but plan to view some later this month and want to be 'genned up' as much as poss beforehand..

Looking at a 2004 and another 2005 CDI - 1 private and 1 at an independant trader in Scotland, both seem to want top dollar also, are these things starting to appreciate

Thanks

Stuart

Hi steve Iv'e got some pictures of the 'flaps'
These are in the inlet manifold, the way I see it is this engine is a twin cam with two inlets valves per cylinder one of which is governed by the swirl flaps.
But I could be wrong
the manifold in the picture is upside down but you can see the rail operation from above if you look down through the gaps in the inlet manifold when the engine is running
The second picture is a close up of the flap with a new seal this manifold had done 160,000 miles when I removed it, 182,000 miles now and still going
kevin

 

[colechelle]

These "flaps" close when you take your foot off the throttle and close of all air to the engine acting like an exchaust brake, controled by the inlet port shut of motor! hope some help, by the way if one "flap" brakes the whole manifold has to be replaced!!

 

[panason1c]

if one "flap" breaks the whole manifold has to be replaced!!

I wonder .....could one simply remove the flaps system completely, rather than repair, would the engine run relatively normally without them?

 

[television]

I wonder .....could one simply remove the flaps system completely, rather than repair, would the engine run relatively normally without them?

Thats an interesting queston

 

[kebo57]

These "flaps" close when you take your foot off the throttle and close of all air to the engine acting like an exchaust brake, controled by the inlet port shut of motor! hope some help, by the way if one "flap" brakes the whole manifold has to be replaced!!

I don't understand this as there 5 inlets ports which branch out in to 10 inlets ports, 5 of which are governed by the swirl flaps, so this wouldn't "close of all air to the engine".
I recon these swirl flaps work similar to a twin choke Weber when you ask for more power then they will open
Kevin

 

[panason1c]

I wonder if they play a part in regulating/smoothing turbo boost pressure and reducing turbo lag?


Edit, Next time i'm working on mine in the 'flaps' area i will disconnect the actuating rod from the electric motor and tie it so that the flaps are held open and see what the engine runs like.