Strange Smell inside Car! Is it a mechanical Problem?

Could it be a smell of ketones? I've noticed it in several company trucks I've had, always on significant hill climbs at high speed. Even my current diesel truck treats me to the smell sometimes. Darned if I can figure out where it comes from.

Mike

If you mean is it the smell of fuel inside my car? then it is not that.

I can only smell it if the car is left for at least half an hour with the door closed while I am away and then it seems to go almost immediately.

It is most noticiable like I said when I park my car overnight - its a strong smell but as I said it does not get worse when driving in anyway - although the smell does come back if I have the doors closed and no air con on but I suppose that is the same situation as leaving the car standing overnight!

The most likely cause as far as I can think is something that smells in the car or on the car mats - but as I said I have cleaned the car out I can't smell anything from anywhere!

I associate strawberries with a sweetish smell, and that could mean coolant leaking from a heater core.

Wouldnt that be something I would smell more when I turn the heater on?

Because its freezing cold and the heater has not smelled any worse!

However, if it is what you suggest what does that mean will happen? The heater won't work when the coolant is out?

Coolant circulates from the engine through the heater core inside the dashboard and back to the engine again, so if the heater runs out of coolant the engine is out too. It doesn't take much of a leak to create the unmistakbly sweet smell of coolant. You might want to have a reliable mechanic check out the source of the smell. It may be something as simple as an old strawberry under the floormat...and it might be someting a little more serious too.

So whats the worst case scenario if it is that?

what would happen if it runs out while im driving?

and like I said before if its a smell coming from the engine and cycling around then surely it should be noticable when driving as it will be moving around and not when stationary?

In my experience IF the core is leaking it will gradually get worse. It doesn't take much coolant for you to be able to notice it. I would have a mechanic take a look and verify whether you have a problem or not.

In my experience it will not all suddenly run out. But you should check the coolant level regularly.

I checked the engine coolant level and its at the maximum line (assuming that is what you meant when you said the coolant)

so it does not appear to be leaking based on its level not going down at all! also the smell seems to be less noticiable today, common sense would lead me to think that maybe there was something that smelt bad on the floor or on my shoe and that when I cleaned my car out the otherday whatever it was that smelled bad was taken out and any remaining smell is just the lingering stale air and will pass with time!

But that would be foolish to assume that when it could be far worse! better to assume the worst than best!

I located what I believe is the cause of the smell - the rear passenger footwell is soaked on both sides!

It was under the mats I have so I didn't notice until I lifted them up.

Is there anything in that area that could leak through and drench the footwells pre-installed carpet on both sides? Or do I have a door leak somewhere which is letting lots of rain water into my car?

I mean its really wet down there - we are talking wet enough to mop it up! What could it be?

I would guess thats not coolant as you mentioned before now?

Probably not given the location. The odor may be mildew. Assuming this is not an old car with a rotted floor the water is coming in through a door or sunroof seal, or possible from a window being left open.

Not coolant... is the trunk dry? That's a common leak area.

Mike

Actually now you mention the trunk - I had a big accident before Christmas, badly damaged my rear bodywork - I had it repaired but for 3 weeks I could not close my boot all the way! I suppose the water could have been collecting since then and the dampness smell has taken a while to get bad enough for me to notice.

The car has done 156,000 miles but its a 98 S40 so it shouldn't be rotting anywhere yet! I take it there are no pipes containing any liquids that could leak out in that area and go through the car floor?

IF its water from outside then I can live with that - my main concern was that something mechanical was damaged and chemicals or something were leaking out - I guess we have ruled that out now?

Thanks for everyones input so far!