Re: Running an engine with no air filter

car what effect

with

It would have very little effect IMO, apart from making the engine sound noisier. Normally the amount of crap an air filter collects in the UK, over thousands of miles of driving on metalled roads, is relatively small. Too little to have any noticeable affect in the short term. OTOH I don't think leaving it off permanently, would be a good idea. If the car was frequently driven on dirt tracks, or in dusty atmospheres, I wouldn't advise running without a filter, but under normal conditions, I don't think there is any significant risk. Mike.

Depending on where the intake is you could get water being drawn into the engine when raining or going through a puddle. An air filter also acts as a sort of flame suppressor in the event of a backfire too.

of

If your air filter actually contains significant amounts of grit, I'd be very surprised. All mine ever seem to contain is crap that looks and feels more like smoke particles than anything else. And that after thousands of miles. There is normally very little grit in suspension in the air over metalled roads, and what little there is unlikely to get drawn into an intake under the bonnet of a car in the sort of amount that would seriously damage an engine in the short term as I indicated in my original answer. Personally I've never seen any significant extra wear in engines run without air filters, but you're entitled as much to your opinion as I am to mine.

In the long term I'd agree. In the short term IMO any damage is highly unlikely. Mike.