UK-POLOS.NET - THE VW Polo Forum

So, i've got a 3 cylinder 1.2 and it sounds horrendous, so I got a cone air filter, took the top of the air box off and took the panel filter off, then took the hose out of the lower half of the air box and connected the cone filter on to this.

It sounds better after a little while of open throttle, but when flooring it, it vibrates the pedal and cabin quite badly.

Popped the hood and duh! It was resting on the air box, so I braced it with wire to hold it up, problem remained!

Went back out, braced it from two sides so it cant be hitting anything in the engine bay, but it still vibrates badly!

The only thing I can think of is that the aggressive acceleration causes it to vibrate so much it hits the bonnet.

The problem being that if I brace it any lower, it will hit the lower air box.

I would remove the lower air box but I have heard it effects sensors and hot/cold air flow so I left in place.

Any ideas guys?

I would take the cone filter off and put the factory air box back on

All the cone filter will do is reduce your MPG and continue to create vibration like it currently is

Failing that, you ned to think about fitting it properly and taking the bottom airbox off too.

alexperkins wrote:I would take the cone filter off and put the factory air box back on

All the cone filter will do is reduce your MPG and continue to create vibration like it currently is

Failing that, you ned to think about fitting it properly and taking the bottom airbox off too.

I honestly can't stand the noise without the filter.

Realistically how much will it reduce the MPG by?

Can be up to 10mpg

Its a common misconception that replacing your air filter on anything that isnt heavily tuned and turbo'd that youll get better economy. Replacement air filters often make performance worse, and burn more fuel as a result

Guessing you dont like the 'electric' sound the engine has?

alexperkins wrote:Can be up to 10mpg

Its a common misconception that replacing your air filter on anything that isnt heavily tuned and turbo'd that youll get better economy. Replacement air filters often make performance worse, and burn more fuel as a result

Guessing you dont like the 'electric' sound the engine has?

Exactly that, it sounds awful but it's a 3 cylinder 1.2 so the filter is the only viable thing I could think of.

I'm well aware it's not for performance, but as long as it's set up I'd like to think it wont reduce my MPG.

You'd probably be better to stick a backbox on it to drown out the engine noise

Failing that, get the engine insulation from a 1.4TDI to quieten down the engine bay.

alexperkins wrote:You'd probably be better to stick a backbox on it to drown out the engine noise

Failing that, get the engine insulation from a 1.4TDI to quieten down the engine bay.

Yeah a backbox was my next plan, but as the cone air filter was cheaper I thought I'd try it now.

I tried to remove the lower airbox but as you look at the engine bay, towards the passenger seat side of the box there's some metal coming in, which stops is being removed easily and I thought this may be a sensor of some description and I also read elsewhere the factory airbox also controls other stuff.

If I just take the lower airbox out (will still have to figure out how to get it out) and get a stiff hose direct from the throttle body then the cone filer in place of the old airbox, could I expect the same or a 1/2/3mpg difference?

Youll still get a drop in MPG no matter what you do unfortunately.

The only sensors are the ones with wires attached. Theres a thermostatic mixer valve inside that mixes hot and cold air, but thats part of the airbox itself.

alexperkins wrote:Youll still get a drop in MPG no matter what you do unfortunately.

The only sensors are the ones with wires attached. Theres a thermostatic mixer valve inside that mixes hot and cold air, but thats part of the airbox itself.

That'll be what it is then, it's moulded in to the box so needs to be pulled towards the battery, which is a battery out job by the looks of things.

If done reasonably well, are we talking ~5mpg loss?

About that, yes.

alexperkins wrote:About that, yes.

Well thanks for your help buddy, I think I'm going to ring up the garage and see if they have a stiffer hose material and can remove the lower air box!

Cheers.