Can a non OEM airfilter affect idle speed?

[PJayUK]

Just reading a few posts about idle speed issues which has raised a few questions that I was wondering if someone can help with.

Basically my 2000 S320 idles when warm at around 850RPM. Last week the car was at a local indi and hooked up to STAR diags. All clear no issues or faults identified. The technician said not to worry about it, but it still seems a little high. He reset all the ECU adaptive values which actually seemed to make the car feel slightly smoother running but had no effect on the idle.

So got me thinking....

The car had a new pair of airfilters a couple of months ago. Unfortunately they were el'cheapo aftermarket ones and not MB ones. I was wondering whether using these might affect the airflow and cause some impact to the idle speed.

Would a good clean of the throttle body and butterfly valve help things out? I seem to recall that the valve flap is rubber or plastic not sure but looks flimsy. Is there a standard procedure for cleaning this, or perhap a WIS bulletin that I could refer to?

Now this will sound daft, but I think this problem has only started since I switch to using Shell V-Power in the car. Could this have caused any impact, on idle speed?

As always any advice is gratefully received!

 

[television]

Air to the engine is drawn through the filter, so could a filter require more energy, speeding up the engine in the process, it possible I think. you can lift the filter off and turn on to see

The engine did not do anything when V power was put in, if anything it would have slowed it down as it retarded the engine a touch

 

[PJayUK]

Might just bite the bullet and buy a proper MB set. Any advice where I can get these from, dealer pricing seems pretty high!

 

[television]

Might just bite the bullet and buy a proper MB set. Any advice where I can get these from, dealer pricing seems pretty high!

There is no where else for them, they are good for some 30 K miles

 

[Number_Cruncher]

>>cause some impact to the idle speed.

Neither the air filter nor the fuel should affect the idle speed - it's under closed loop control from the engine management system.

 

[television]

>>cause some impact to the idle speed.

Neither the air filter nor the fuel should affect the idle speed - it's under closed loop control from the engine management system.

Then the test is to remove the filter box and start the engine and slowly close the air intake aperture with the palm of your hand, and see if the idle changes, or one could just start the car and lift the filter box off and see if anything changes

 

[kth286]

if the filters are a poor fit in the housings then it may be there is air going into the engine via gaps in between the filter and the housing.

cheap copy filters often lack precise fit and structural rigidity.

 

[bigasotonuk]

The Air Filters i recently bought for my C43 from MB were £40each. I have now taken the 3rd party pt. no.'s off of them and will buy from a local motor factors in future.

 

[HERBIEMERCMAN]

hi pjuk, i have run my engine without the filter, i have also seen the filter 90% blocked with dust etc. i once ran the engine with the inlet manifold off, non of this had the slightest effect on the tick over rpm. i would be looking at what somone has allready said, the ecu. i would also try disconnecting the maf ( mass air flow sensor ), this measures minute changes in temperature and pressure and sends signals to the ecu. i had a new maf fitted recently, as the car was undriveable, not sure about my tick over at the time, but it is a key control item in the area you are looking at. herbiemercman.