Car air filters
 

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[Closed] Car air filters

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Not the ones that filter the air into the engine, the ones that filter the air into the cabin.

Planning on driving the midget home whenever the weather 'improves' enough to remove some of the salt off the road. But whenever I do any significant motorway miles, especialy in trafic I arrive smelling of fuel and in need of a shower. No probles with the roof down though as theres plenty of fresh air (and its not an exhaust/fuel leak) as all that gubbins is new.

So, what do modern cars have that mine doesn't?


 
Posted : 19/01/2010 4:29 pm
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"So, what do modern cars have that mine doesn't?"

No holes! lol

Seriously though, you shouldn't be smelling of fuel. You have a small leak somewhere. Or it's not burning it right in which case it's not set up right.


 
Posted : 19/01/2010 4:31 pm
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proper engine crankcase breather recirculation systems?

there's somethign wrong if ou're gettign fuel vapour in the cabin.


 
Posted : 19/01/2010 4:31 pm
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I'm fairly convinced its not me, no problems arround town, country roads etc, only after long extended motorway runs.

Air intake is under the front bumper, goes down a long thick pipe to the fan/heater box then gets ducted into the cabin.

Fuel runs form a tank under the boot, through a copper pipe under the car and upto the fuel pump so no way of leaking into the car.

Exhaust is stainless, so no rot.

The cabin is pretty much sealed appart form the air intake, unfortunatley I cant test it with the air off as I'd cook!


 
Posted : 19/01/2010 4:42 pm
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you have a midget that smells of petrol, and you come onto a public forum to pronounce this?!? fantastic!

are you in brugge?


 
Posted : 19/01/2010 4:43 pm
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The fuel won't be leaking into the car, the vapour will be.


 
Posted : 19/01/2010 4:50 pm
 tron
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Something isn't right with the car. I suspect the carb is either set up too rich at part throttle (very likely), or the ignition system is in poor nick, causing incomplete combustion.

My girlfriends (fuel injected, cabin filtered, fairly airtight) Golf stank of fuel at the traffic lights when we first got it. A new set of spark plugs and BANG! the stink was gone.


 
Posted : 19/01/2010 4:52 pm
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"BANG! the stink was gone"

which with a cabin full of fuel vapour is a distinct possibility...


 
Posted : 19/01/2010 4:57 pm
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Mr Nutt, it's getting to you isn't it?

Hmmmmm, I'm not convinced theres plenty of ventilation under the bonnet (masses of space), so can't see how at 65mph with the air rushing through fuel vapour could build up? But it's due a service so I'll replace the plugs and leads etc, check the points then take it to a rolling road for someone to setup the carbs properly (they do need doing, they were tweaked to get it through the mot emissions test).


 
Posted : 19/01/2010 5:09 pm
 tron
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Ha! Had a fuel line rub through on an old car once. Bloody lucky it didn't go up!


 
Posted : 19/01/2010 5:11 pm
 tron
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You can smell petrol at concentrations that are nowhere near flammable as far as I'm aware.


 
Posted : 19/01/2010 5:12 pm
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It's not building up - it's simply flowing through the vent system into the car. Trust me.

Where are you? If you're in Scotland I can point you in the direction of someone who can sort your car out...


 
Posted : 19/01/2010 5:14 pm
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I'm still not convinced, the air inlet is right at the front behind the grill/bumper, the fuel pump is on the same side but 3ft back, the carbs are on the opposite side 3ft away.

I'm down in Reading, know a few clasic car guys so i'll ask them who to go to.

Might take it upto the MGOC garrages for a tune up, their parts are reasnobly cheep and they must know what they'r doing!


 
Posted : 19/01/2010 5:36 pm
 tron
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Put it this way, in the golf the air intake for the engine is down behind the driver's side headlamp. The air for the vents comes in through the scuttle, and there is a rubber sealing strip that runs the width of the scuttle to avoid mixing of underbonnet and cabin blower air.

1) You'd think there was no way for petrol vapours to make their way up the inlet tract, through the throttle body, and down the inlet pipe, especially not under a constant vacuum due to the fact the engine's running.

2) You'd think there was no way for smells to get from under the bonnet to the cabin intake.

But somehow, it did. At the same time as I did the plugs, I think I did the oil. Any excess petrol tends to wash down the bores and get into the oil, so the smell may get back out through the crankcase ventilation system.


 
Posted : 19/01/2010 5:46 pm
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Just to put a little bit of spin on it...

You have obviously changed the exhaust to get a stainless one, is it too short? If the exhaust exit doesn't come out far enough the aerodynamics of the car will draw the exhaust fumes back round the boot lid and into the cabin, this also becomes more apparent at speed. Its called the boundary layer effect IFIRC. You tend to smell this as exhaust fumes rather than petrol though but if your midget is running rich you would also get a lot of hydrocarbons coming out the exhaust which could lead you to believe you are smelling of fuel.

Just a thought and something else to consider


 
Posted : 19/01/2010 8:28 pm
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I had what sundaywobbler says in my Herald convertible when I fitted a twin exhaust to it - the boot seal was knackered and the cabin used to fill up with exhaust gas at speed.


 
Posted : 20/01/2010 8:29 am