I'd noticed a drop off in fuel economy, so opened up the airbox and checked the air filter when I had a spare 5 minutes.

The filter had only been in for 6k miles, so should have plenty of life in it, but what I found shocked me a little bit.

The air filter itself was covered in a fine powder on the dirty (unfiltered air) side of the filter, which seemed to be clogging up the filter material.

The clean (filtered air) side was still spotless and not a trace of dirt.

On inspecting the airbox, again the dirty side was full of this very fine powder, so I took the louvres out, washed it off and took a damp cloth to the filter box and dirty side intake pipes to remove all traces of the material.

Once dry, I put it all together again and since i had a new filter to hand, that went in.

The end result was that I got a jump of 8mpg on the same route, even though I was pushing on after the change.

Closer inspection of the dirt, revealed that it looked and felt like very fine sand grains / balls of glass, with a greyish colour.

Based on that I can only imagine that some of that volcanic ash that was up in the sky, came down over the last few months and has been sucked into the air intake and deposited there.

I'd suggest that anyone who has 5 minutes to check their car should do the same.

On the plus point it shows the filter was doing it's job

I'd also be interested to see if anyone else had similar and if those with the cotton/foam filters have the same or a clean airbox.

Edited 16 July, 201015 yr by cheezemonkhai

Hmm, I was just thinking it was the hot weather, but it's got to be worth a look now my strut brace is off...

Hmm, I was just thinking it was the hot weather, but it's got to be worth a look now my strut brace is off...

I thought it was the hot weather too, until I realised just how badly south it had gone.

Running your finger along the air filter left a clean patch on it, which showed just how much crud was sat on the surface.

I thought it was the hot weather too, until I realised just how badly south it had gone.

Running your finger along the air filter left a clean patch on it, which showed just how much crud was sat on the surface.

I'm going to sound like such a pleb, but I couldn't get the casing open!

I got the cover off the engine, undid all the screws, took off the heat shield, but couldn't get it apart.

Is there a nack? Does the pipe need to come off the side?

I didn't have a lot of time as I expected it to be a 5minute job, but before I take another go with a bit more time, I thought I'd ask.

its not ash, as they ash didn't touch down

Any long spell of dry weather causes very dusty conditions also high pollen counts may cause similar problems . I think now that you've mentioned it I'll have to go & check mine !

I cleaned mine a couple of weeks back and it wasn't so bad. Mainly lumps of salt grit in the airbox, and insects stuck in the filter. No ash to report!

Don't get me wrong, I know they usually get full of dirt and pollen, but this stuff just looked and felt different.

Regardless of what it is (and we did have a lot of pollen) well worth a quick look

Don't get me wrong, I know they usually get full of dirt and pollen, but this stuff just looked and felt different.

Regardless of what it is (and we did have a lot of pollen) well worth a quick look

worth a check .... where in the country are you based [just thinking of where any ash may have dropped]

worth a check .... where in the country are you based [just thinking of where any ash may have dropped]

Hampshire/Dorset area most of the time.

Same Problem, Same Solution, Same Result