Black gunk in exhaust trims

[austenw90]

Hi there

Whilst cleaning my Fabia vRS this afternoon and washing the chrome exhaust trims I ran my finger inside the trims to find my finger came out completely covered in a thick slime like black oil residue. The entire inside of the tailpipes were greasy with whatever this is.

Now I've never seen this before on any petrol car. I know that diesels can get coked up but with black soot rather than liquid.

Any thoughts? The car is currently under oil consumption testing by Skoda UK. A few more miles (300 minimum I am told) and I will be booking it in. I also did a hot dip today just out of interest, 5 minutes after engine shut off, oil temp 85 degrees, parked on a flat surface, no oil to be seen, only a little on the orange ball at the bottom of the dipstick. :/ obviously I won't be adding oil for the purposes of an accurate test.

Another question, does anyone know at what point the oil warning like is set to come on?

Edited 19 January, 2014 by austenw90

[fabiamk2SE]

Thats where it all is then. Firing out the exhaust.

It just confirms your thoughts of high consumption i think.

[austenw90]

Thats where it all is then. Firing out the exhaust.

It just confirms your thoughts of high consumption i think.

Thanks for the reply. Are my fears correct then do you think. This is oil residue?

[James I]

Our Fabia also makes a lot of exhaust coal, to the point where it flies up and sticks to the back of the car.   Our Yeti has clean tail pipes and it is a diesel, even after 107,000 miles.

 

 Fabia exhaust blackness is normal

[fabiamk2SE]

Yeah i think its definitely oil. Most likely getting past your piston rings, or your valve stem seals. Id say its the piston rings though.

Im not actually a mechanic, but id of thought when skoda get the results for your oil consumption test, i think they will do a compression test to check your piston rings, and then maybe replace those or drop you a nice shiny engine in.

The new common rail diesels are very clean indeed. Nothing like what they used to be.

[James I]

This is a bit inaccurate to say the least, we all know MK 2 Fabia VRS has a thirst for oil, however they do not produce blue smoke under acceleration or when revs are held constant neither do they produce blue smoke from the exhaust when on overrun so rings or valve guides are probably as new and not a problem.

 

 The gunk around the tail pipes is the same as the gunk around the tail pipes on my Golf and my Lads Lupo, it is quite normal for a petrol car and nothing to do with rings or valve guides...

 

 Your oil consumption test will result in a breather mod and a remap, then if that fails you will be offered a short engine, reason being from what people let slip but will not admit too, is that crank case pressure is quite high, this in turn blows oil vapour into the breather system and then back into the inlet manifold and is burnt through the engine with the air fuel mixture, the breather mod does help with this to some extent.

 

 Do your oil test with the dealer and don't worry about the tail pipes, they will always be black and sootie/slimy

[stu_mcl]

Nothing todo with oil usage, they all do it

Mine done it and never used a drop of oil

[sharkrider]

what stu says, its normal, should translate to little soots dots on the back of your car if you are driving quick enough :P

[Sparkly]

Also permanently cleaning my tail pipes, car barely uses oil.

[austenw90]

It has already had the breather mod but I have reported high consumption, I guess the test will establish whether or not what I interpret as high is normal or not.

On a handful of occasion I have noticed white smoke from the exhaust when I put my foot down. Defiantly not water vapour as this has been when the engine is well up to temp. The kind of smoke you get when the engine has too much oil but it hasn't been above maximum since I've had it.

Edited 19 January, 2014 by austenw90

[fabiamk2SE]

I stand corrected then . I was just going off what iv read on one having piston rings done and my basic understanding of bike engines.

Glad youve proved me wrong .

[James I]

Ours does that too it has always done it but as already said fabias that don't use oil also do it.

Sent from my iPhone using Tapatalk

[James I]

I stand corrected then . I was just going off what iv read on one having piston rings done and my basic understanding of bike engines.

Glad youve proved me wrong .

I know what you are saying mate, however the oil use is well discussed on this forum and some of it is worth a read too.

Sent from my iPhone using Tapatalk

[fabiamk2SE]

Iv only read bits. As it doesnt directly concern me i havent taken hours to read through it all.

Im glad i was wrong though.

My little 3 pot has never used a drop, so im alright jack haha.

[XK140]

My vRS is like that.

If it's not oil then it must be unburnt fuel,which suggests that at times the engine may be running rather too rich.

But what do I know,and the people should know,namely VAG,don't appear to want to tell.

My limited knowledge tells me that if it is rich then it will be at low revs,and if you drive gently in "D" the dsg rarely lets the engine exceed 3000 revs.

I wonder if you drove for say 100 miles with the box in "S" would you end up with cleaner tail pipes?

Edited 19 January, 2014 by XK140

[fabiamk2SE]

I thought that. But do modern cars get much unburnt fuel in the exhaust? With all the sensors and what not.

My bikes carbed and that doesnt get any gunk in it. When you do get unburnt fuel in the exhaust, doesnt it ignite in the exhaust and cause it to pop?

Im waiting to be corrected again, but if its not oil and its not fuel. Can somebody please explain to me what it is? Always up for being educated

[XK140]

For the record my 350z has very clean tail pipes.

My previous vRS Octy had dirty tail pipes and that used some oil.

Is it a hazard with engines with forced induction?

The other sort of connected fact is that the engine oil on both soon take on a black tinge quite soon after a change.

[fabiamk2SE]

Oh iv reread it. So it is oil? But its going round and recycling though the engine with the air? Thus finding its way out of the exhaust valve?

But if the ones with 'no oil consumption' do it, then what?

Edited 19 January, 2014 by Otaylor38

[Furbytom]

Mine has the slime/soot but uses only a minimal amount of oil.

Is yours an older CAVE engine or the newer CTHE unit?

[vrskeith]

Check out with sk4gw,as he has become a bit of an expert in the field of Fabia vRS  Engine issues!

 

God knows what your Cat is like then.

[Ootohere]

Re Oil warning light, i got my car back after lending it for 3 weeks over Xmas/New Year..

 

It does not use oil. & it had 3.7 litres of new oil & a new filter in. Hot check was at the top of the Cross Hatch.

It came back to me having only done 520 miles.

 

Hot dip and the Oil was just above the bottom Orange Ball.

The Yellow Oil light or the Red Oil Pressure light had not come on.

It took 1.2 Litres of oil to get it back to the top of the Cross Hatch on a Hot Check.

 

1,500 miles since done by me, and no oil used since.

Last night at 2 *oC Ambient it was 20 miles covered before the oil even showed 83*oC from a cold start.

 

Short Journeys and styles of driving can use oil.

My car goes on loan on Friday so interested to see what happens this time with Oil Used.

 

george

[austenw90]

Mine has the slime/soot but uses only a minimal amount of oil.

Is yours an older CAVE engine or the newer CTHE unit?

Mine is a CAVE I believe. Must be a very late one on a 62 plate.

I am told that the modification on the CTHE is simply piston rings which are man enough for the job. This is what the dealer said.

[Ootohere]

Ask the Dealer or person that told you that to write it down and put their name next to it.

Did they mention how the CTHE runs a totally different Map to the CAVE?

 

No the CTHE is not only different Piston Rings, 

there is a thread with the rest of the engine part number changes, and that includes different Pistons.

 

http://briskoda.net/forums/topic/279292-cthecave-enginewhats-thediffrence

[austenw90]

It seems that no one who needs to be are appropriately trained in car dealerships. It is unbelievable what they can tell you and be wrong or not completely correct. These people should know their product but it seems like it is down to the customers to know more than they do. Either that or you have to double check everything you are told or not feel completely confident in what they tell you.

An example is car salesmen, very few know much about what they are selling... Surely the first rule of selling is to know your product inside out.

Edited 20 January, 2014 by austenw90

[Ootohere]

Often you know quite easily that they might be lying.

 

Their lips move.