Melcp987

Hi all
i hv a 2009 s450 awd and when i slow down and speed up, its bogging at 40-60km an hr.
this bogging went away when the main intake manifold flop was stuck at open position.

after i got the flap replaced and back to normal, its started bogging again.

can this be caused by something else.
Maybe need a tranny flush
or new fuel pump.
maybe even caused by unbalanced drive shaft.

if anyone has any idea am all ears. Thnx

Jaap

Check and then double-check that the intake manifold flap is correctly installed and works as it should.

Melcp987

thnx. Intake flap and lever functions properly. It actuates when the gas is pressed.
when it was stuck open it was actually running smooth n bogging was gone (high gas consumption though cuz it doesnt close when on idle lol).

Melcp987

It almost feels like its either not getting enough air or fuels at those speed range when its at low rpm. It doesnt bog when im heavy on the gas pedal.
so it mostly happening when after slowing down and picking up speed again.
It bugging the crap out of me. Lol

Jaap

Next step is probably to check for air leaks.
Do you have a smoke machine?

Melcp987

I dont have a smoke machine.
Could u elaborate on what that is what i do with it?
Thnx again

Melcp987

Isnt it odd that its only happening at 40-60kph?
im thinking of getting the trans fluid change and getting new fuel pump as well. Im also not getting any CEL code so its prolly nothing electrical or sensor related right?

im also gonna se if the mech can do a vacuum leak test n check fuel pressure as well.