I recently purchased a 2013 1.6 Ford Focus zetec. There is a nasty smell coming from inside the car. There has been new filters put in and I have used Holts Sanitiser for the air vents etc. But to no effect. There is no dampness anywhere.Can you help me in getting this smell eradicated.  Thanks

Is it an "Aircon Bomb" that actually cleans the entire aircon system, that you used, or just a sanitiser spray ??

It was a can of Holts Santiser. You put the air-conditioning on full. Make sure the air circulate is on. Then you place the can behind the two front seats and depress the lever. There is a spray that comes out for.Then you exit the car leaving it to fill the car and it is supposed to get into he vents via the car air circulation switch.

No it wasn't an air bomb. It was a can of Holts Sanitiser spray.  You put the can behind the two front seats. Turn the air con on and car circulation on as well. Depress the can lever and it shoots out spray which is supposed to be drawn into he vents by the the air circulater. You leave fir about 10 mins

That is an air con bomb.  I've never had much luck with them on a proper smelly system, only one where the smell was barely detectable anyway.

What you actually need is a foaming spray that gets directed right into the evaporator using a long tube through the vent or drain holes.  The foam sits on surfaces long enough to kill bacteria and fungi.  The atomised sprays just blow straight past them.

Best one was Wurth but I can't see that from a quick online search today.  This Liqui-Moly looks very similar. 

Liqui-Moly A/C System Cleaner Spray, Remove Bacteria & Mold 250ml 4087 1 unit | eBay

 

My car had toothpaste breath for about two days after using aircon bomb, but after that the sour milk-scent made its return. So I have been thinking about these foam things. Are you supposed to fill all the vent holes or do you fill from the core until the foam pours out of the vents? Does it just dissapear by itself?

18 minutes ago, LarsfromNorway said:

My car had toothpaste breath for about two days after using aircon bomb, but after that the sour milk-scent made its return. So I have been thinking about these foam things. Are you supposed to fill all the vent holes or do you fill from the core until the foam pours out of the vents? Does it just dissapear by itself?

On the Mk2 Focus you can access the evaporator directly through the drain behind the carpet in the drivers footwell.  (Or passenger footwell if LHD lol).

The foam should expand to fill the HVAC box and the vent ducts, but if you can add it directly to the ducting as well, that should make for more thorough coverage.  Some of the temperature or direction flaps may be closed which can restrict how far the foam gets.  A much bigger issue on cars with automatic climate than those with manual control.

Leave the system OFF for about 15 minutes and the foam will expand as far as possible and then slowly disappear.  After 15 minutes you can turn the fans on slow speed - if any foam blows out then switch off and leave it another few minutes.  If no foam blows out then you can run the fans at high speed to make sure the whole system is dry and aired through.

Have you used your 'nose' to sniff around to actually smell where the bad smell might be coming from ?

Get on your knees and get sniffing, even sniff at the air vents 

True story this is.......Our old Pug 405 started to smell really bad inside and it was coming from all the air vents, turns out a mouse had made itself a nice nest behind the bulkhead, eventually the mouse died and started to rot, the smell as we ragged out the nest & rotting little body was overwhelming. 

Depends on what the smell is.

My last Focus purchased had a rather nasty non air con smell.

It turned out to be the remains of a pile of  vomit which had matured under the rear seat squab and soaked into the seat fabric.

It all cleaned up nicely with a bit of effort.

ScaniaPBman.

As someone with a hypersensitive nose and a severe phobia around bodily fluids, I have had to sell more than one car immediately after delivery because of the above!!

Thought buying brand new would avoid that when I had the funds for finance, but quickly realised I couldn't tolerate the new car smell either! 🤦‍♂️

Hello I have the smelly AC evaporator issue on my 2017 Focus 1.0 Litre Ecoboost. An Aircon bomb shifted it for a few weeks but it is back. I have some new cleaner with along reach Flexible tube. Can anyone advise the easiest or best way to direct it straight on to the evaporator without dismantling the fascia etc please.

43 minutes ago, Graeme_r said:

smelly AC evaporator issue on my 2017 Focus

When was the cabin filter last replaced ?

Once you get a smell you won't shift it for very long as the bacteria will be trapped in the filter.

The cabin filter wasn't smelly.  I replaced it in August 2024, and also again November 2024 after I had used the aircon bomb.  The carpets are bone dry too.  It is the evaporator.

19 hours ago, Graeme_r said:

I have some new cleaner with along reach Flexible tube. Can anyone advise the easiest or best way to direct it straight on to the evaporator without dismantling the fascia etc please.

There's no access from dismantling the fascia.

You can reach the bottom through the condensate drain pipe in the drivers footwell.  But you're unlikely to cover the whole evaporator effectively like that.  So I would also going in from the centre vents, making sure the direction was set to face before switching off the car.

Drivers seat 😝