Any idea what we are facing here?

My Octavia 2005 mk2 started producing these huge blooms of grey smoke.

It is a 1.6 petrol engine. Driven 310 000km

Sometimes it runs just fine but occasionally it starts pushing this grey/white smoke out of the exhaust and runs idle very roughly. And sometimes it seems to run only on 3 cylinders.

The smoke has a strong odor of fuel. Not sweet like you would get when burning coolant.

 

Yesterday when I went to a vehicle inspection the inspector said that hydro carbon levels were about 1000. That's roughly 10 times more than accepted...

So that seems like it's pushing unburnt fuel through the system?

I just changed sparkplugs before hand.

 

First it started doing this when warm. Now it seems to smoke every time i start it.

 

Are we talking about burnt head gasket or maybe a coolant temp sensor fault making it run on extremely rich?

I have video on the problem but I can't link it right now with...

Edited 26 June, 20196 yr by Kaamio
Typo

Could be that the spark plugs or ht leads are starting to break down.

Just changed the sparkplugs. No affect. Gotta check those leads too.

Also forgot to mention that there is no fault codes at all.

Ill pull out the plugs tomorrow and check compression on each cylinder. That should maybe give some clues

Edited 27 June, 20196 yr by Kaamio
Typo

Leaking injector maybe? 

And be quick to fix before the catalytic converter goes to hell too. 

Is this a thing in skodas? Anyway I can test it? Pulling out the injectors and squirting them? 

Pull them out and crank the engine. One by one that is, test one after another. Put each one in a plastic see through bottle to see the spray pattern. They should be on top of the intake manifold as i recall. Hope i am wright. 

Edited 27 June, 20196 yr by krigl

At that mailage they could easely be faulty. 

A 2005 1.6 is an FSI, not sure I’d be squirting into a plastic bottle even if you could get the injectors out to do it. 

if its overfuelling from the injectors it would take the Lamda sensor outside of limits and bring up a fault code.

 

So its not consuming oil then  its coolant and given the white smoke, if it were an earlier generation vehicle with a brake servo I would be confident that it was brake fluid, is it possible with an ABS system for brake fluid to be sucked into the inlet manifold?

 

Whatever it is will be killing the Cat.

Just changed that temperature sender unit and fixed a leaking intake manifold seal. Checked the compression. Over 14bar in every cylinder so no problems there. Nevertheless it's still smoking like hell... 

This might sound a bit bizarre but can you get someone to hold a large plastic bin bag over the exhaust to collect a bagful of the peak smoke?  If you can, once the smoke has cooled examine the insides of the bag for either oily condensate (burning engine oil or diesel) or water (cooling system).  Smell it, too,  Unburnt engine oil is a bit sweet smelling, burnt is acrid.  Unburnt fuel is also distinctive.

 

Don't hard-fasten the bag to the exhaust; if you don't have a willing volunteer, use an elastic band but don't overdo things - the idea is to collect a sample, not blow a head gasket!

 

Other things to look out for:

1. Oily smoke on acceleration suggests piston rings or bores; if coupled with uneven running possibly misbehaving injectors

2. Oily smoke on overrun suggests valve guides or valve stem seals

3. A burst of smoke immediately on accelerating after overrun could be from guide/stem wear.  Look for smoke on sustained acceleration to suggest bores/rings.

4. The usual checks on cooling water for oil emulsion or acrid smell of burnt oil - possible head gasket.  There's another thread on here recently about disappearing cooling water which covers much about head gasket issues.

 

 

53 minutes ago, StickyMicky said:

This might sound a bit bizarre but can you get someone to hold a large plastic bin bag over the exhaust to collect a bagful of the peak smoke?  If you can, once the smoke has cooled examine the insides of the bag for either oily condensate (burning engine oil or diesel) or water (cooling system).  Smell it, too,  Unburnt engine oil is a bit sweet smelling, burnt is acrid.  Unburnt fuel is also distinctive.

 

Don't hard-fasten the bag to the exhaust; if you don't have a willing volunteer, use an elastic band but don't overdo things - the idea is to collect a sample, not blow a head gasket!

 

Other things to look out for:

1. Oily smoke on acceleration suggests piston rings or bores; if coupled with uneven running possibly misbehaving injectors

2. Oily smoke on overrun suggests valve guides or valve stem seals

3. A burst of smoke immediately on accelerating after overrun could be from guide/stem wear.  Look for smoke on sustained acceleration to suggest bores/rings.

4. The usual checks on cooling water for oil emulsion or acrid smell of burnt oil - possible head gasket.  There's another thread on here recently about disappearing cooling water which covers much about head gasket issues.

 

 

Ok. Thanks for the tips! 

Just cleaned map sensor and both lambdas and checked/removed air filter but no affect on the smoking.

I did this "collect exhaust gas"-thing and there was mainly water(?) and black soot.

Guess I gotta admit it's something serious... I think Im gonna sell it for spare parts 😛 No point making a total engine overhaul on a 1000€ car.

 

Edit: Also engine oils and coolant are clear. No mayo there.

Also it doesn't build up pressure on the cooling system.

Edited 28 June, 20196 yr by Kaamio

That amount of smoke isn’t down to a sensor or fueling. 

 

Thats something burning, be it oil, water or whatever. Given the mileage I’d say it’s probably due an overhaul or replacing. 

3 minutes ago, Tech1e said:

That amount of smoke isn’t down to a sensor or fueling. 

 

Thats something burning, be it oil, water or whatever. Given the mileage I’d say it’s probably due an overhaul or replacing. 

Unfortunately it's starting to look like that 🤦‍♂️

@Kaamio - Well, I'd agree with Techie here, so check your engine oil, coolant and brake fluid levels.

1 hour ago, KenONeill said:

@Kaamio - Well, I'd agree with Techie here, so check your engine oil, coolant and brake fluid levels.

Already did. That's the strange thing! They are all clear! Also checked the vacuum line for brake cylinder. Dry as a bone. 

This is a real off-the-wall thought but just in case; is there any chance you (or someone) has put diesel in the fuel tank?

 

16 minutes ago, StickyMicky said:

This is a real off-the-wall thought but just in case; is there any chance you (or someone) has put diesel in the fuel tank?

 

Good point but I highly doubt it. It's been refilled several times (by me) since this problem started little by little. Gotta ask the wife though. She drove a diesel post office car so I can't rule that out 😅