Smoke coming through air filters
Smoke coming through air filters
Author
Discussion

NobleNick

Original Poster:

77 posts

251 months

Thursday 22nd October 2009
quotequote all
Has anybody experienced or have any knowledge of this?
After a run, when the car is idling(letting the turbos cool)whisps of black coloured smoke rise from the air filter locations. Then when I turn off the engine I get a little bit more and then it goes. Doesn't happen at any other time.
I've been told this is the gas/vapours from the turbos being released and blowing back out the air filters at the back. Apparently if I cleaned the filters I would never see it and its perfectly normal?
Anybody??

AMG Merc

11,955 posts

282 months

Thursday 22nd October 2009
quotequote all
NobleNick said:
...whisps of black coloured smoke rise from the air filter locations.
I've been told this is the gas/vapours from the turbos being released and blowing back out the air filters at the back.
Not normal, but if they're saying the filter traps the smoke then it may be the filter/s. Sounds more like split turbo oil-feed hose to me though - dripping oil onto hot surface when you stop (you wouldn't easily see it when you're moving).

joust

14,622 posts

288 months

Thursday 22nd October 2009
quotequote all
I'd get the swirl pot and breather system checked along with the oil level if you haven't already.

Excess fumes from the breather go back into the inlet but you shouldn't be getting smoke (at least I've not seen it).

A blocked swirl pot would probably cause this.

J

daddysumo

2,545 posts

242 months

Thursday 22nd October 2009
quotequote all
Ok, if the engine is running the direction of the air movement is from the outside of the filter to the inside, and at what must be litres per minute how can fumes be exiting the filter as it would be going against the flow of air ?
I'm confused, any fumes that come via the breather go back into the engine when its running AKAIK.

NobleNick

Original Poster:

77 posts

251 months

Friday 23rd October 2009
quotequote all
AMG Merc said:
NobleNick said:
...whisps of black coloured smoke rise from the air filter locations.
I've been told this is the gas/vapours from the turbos being released and blowing back out the air filters at the back.
Not normal, but if they're saying the filter traps the smoke then it may be the filter/s. Sounds more like split turbo oil-feed hose to me though - dripping oil onto hot surface when you stop (you wouldn't easily see it when you're moving).
The AA have said "normal, nothing to worry about". A Noble service garage with a good reputation has said "normal, sounds like dirty filters". A Noble service garage with not quite such a good reputation has said "normal, nothing to worry about".
So frustrating!!!

NobleNick

Original Poster:

77 posts

251 months

Friday 23rd October 2009
quotequote all
joust said:
I'd get the swirl pot and breather system checked along with the oil level if you haven't already.

Excess fumes from the breather go back into the inlet but you shouldn't be getting smoke (at least I've not seen it).

A blocked swirl pot would probably cause this.

J
Oil level checked before I use it, always topped up.
Whats a swirl pot??
Its not like thick smoke more like when you've just lit a match say or a candle

NobleNick

Original Poster:

77 posts

251 months

Friday 23rd October 2009
quotequote all
daddysumo said:
Ok, if the engine is running the direction of the air movement is from the outside of the filter to the inside, and at what must be litres per minute how can fumes be exiting the filter as it would be going against the flow of air ?
I'm confused, any fumes that come via the breather go back into the engine when its running AKAIK.
So, if I'm stationery and the car is running, is their still air being drawn in through the filters? (Try not to laugh if this is a stupid question!)

roi354

2,380 posts

228 months

Friday 23rd October 2009
quotequote all
NobleNick said:
joust said:
I'd get the swirl pot and breather system checked along with the oil level if you haven't already.

Excess fumes from the breather go back into the inlet but you shouldn't be getting smoke (at least I've not seen it).

A blocked swirl pot would probably cause this.

J
Oil level checked before I use it, always topped up.
Whats a swirl pot??
Its not like thick smoke more like when you've just lit a match say or a candle
The breather system in a standard car vents back into the inlet tract just past the filters. You'll see the feed to the front filter is on a T piece just behind the filter if you have them front mounted. I'd suggest removing the hoses from the T piece and runnng the car up until you see your smoke.
If its coming from the hose you've removed, Joust is right. If not then I'd suggest buying a filter cleaning kit and report back whether its still doing it.


Rob

NobleNick

Original Poster:

77 posts

251 months

Friday 23rd October 2009
quotequote all
roi354 said:
NobleNick said:
joust said:
I'd get the swirl pot and breather system checked along with the oil level if you haven't already.

Excess fumes from the breather go back into the inlet but you shouldn't be getting smoke (at least I've not seen it).

A blocked swirl pot would probably cause this.

J
Oil level checked before I use it, always topped up.
Whats a swirl pot??
Its not like thick smoke more like when you've just lit a match say or a candle
The breather system in a standard car vents back into the inlet tract just past the filters. You'll see the feed to the front filter is on a T piece just behind the filter if you have them front mounted. I'd suggest removing the hoses from the T piece and runnng the car up until you see your smoke.
If its coming from the hose you've removed, Joust is right. If not then I'd suggest buying a filter cleaning kit and report back whether its still doing it.


Rob
Thanks for that.
I was going to get the clening kit this weekend, I think I'll do that anyway.
With regard to the hose could I go for a run and then remove this hose before I shut the car down, as this is when I get the smoke?

roi354

2,380 posts

228 months

Friday 23rd October 2009
quotequote all
NobleNick said:
Thanks for that.
I was going to get the clening kit this weekend, I think I'll do that anyway.
With regard to the hose could I go for a run and then remove this hose before I shut the car down, as this is when I get the smoke?
Yes, but be careful of the hot bits and the moving stuff eh wink

AMG Merc

11,955 posts

282 months

Friday 23rd October 2009
quotequote all
NobleNick said:
The AA have said "normal, nothing to worry about". A Noble service garage with a good reputation has said "normal, sounds like dirty filters". A Noble service garage with not quite such a good reputation has said "normal, nothing to worry about".
So frustrating!!!
Indeed! So, these experts are saying this is normal but that you have a dirty filter? Hope it's as simple as that then - let us know.

NobleNick

Original Poster:

77 posts

251 months

Friday 23rd October 2009
quotequote all
roi354 said:
NobleNick said:
Thanks for that.
I was going to get the clening kit this weekend, I think I'll do that anyway.
With regard to the hose could I go for a run and then remove this hose before I shut the car down, as this is when I get the smoke?
Yes, but be careful of the hot bits and the moving stuff eh wink
Yep! Good advice, thanks for your help

NobleNick

Original Poster:

77 posts

251 months

Friday 23rd October 2009
quotequote all
AMG Merc said:
NobleNick said:
The AA have said "normal, nothing to worry about". A Noble service garage with a good reputation has said "normal, sounds like dirty filters". A Noble service garage with not quite such a good reputation has said "normal, nothing to worry about".
So frustrating!!!
Indeed! So, these experts are saying this is normal but that you have a dirty filter? Hope it's as simple as that then - let us know.
Yeah I will let you know.
Thanks for your help

JLSELAN

405 posts

262 months

Friday 23rd October 2009
quotequote all
NobleNick said:
daddysumo said:
Ok, if the engine is running the direction of the air movement is from the outside of the filter to the inside, and at what must be litres per minute how can fumes be exiting the filter as it would be going against the flow of air ?
I'm confused, any fumes that come via the breather go back into the engine when its running AKAIK.
So, if I'm stationery and the car is running, is their still air being drawn in through the filters? (Try not to laugh if this is a stupid question!)
Absolutely--just try putting a plastic bag around the filters to prove it--the motor is basically an air pump, and it will just sputter and stop if it gets no inlet air through the filters.