Hello,

Of late, I have been noticing heavy discharge of black smoke when I press the Accelarator Pedal to the floor. This happens only when I press the Pedal to its extreme position and the Turbo kicks in.

Last week, when I left my car for its scheduled service at the Skoda Center, the guy at the Center told me that my Turbo Charger has failed and needs replacing. I have this smoking issue only when I drive the Car aggressively, otherwise, the car emits no visible smoke at all.

What I want to know is, should I go in for a replacement right away? or should I wait for the Turbo to fail completely? If it is ok to wait, will this faulty Turbo cause any other damage on/in any other car system/part?

Thank you.

I very much doubt its failed if its still working, ie you can feel the boost kicking in.

Black smoke is normal when under load if it hasn't been 'cleared' out for a while or if really excessive its usually sign of a stray boost pipe or similar.

Unless you are down on power or your car sounds like a police car then I suspect the turbo will be fine.

As JRW said, first check all turbo piping for leaks. Boost leaks make for a lot of black smoke as air measured by the air-flow meter doesn't make it to the engine.

Failed or failing turbo bearings will cause blue smoke. Generally you would get a big puff of white smoke on start up to.

Thanks all for sharing this great Information which you all did.

Just to add on, the technitian there at the Skoda Center had used the words "Bleeding Turbo" to explain to me the actual fault with the Turbo Charger. He had said that it (The Turbo) was "Leaking Oil". I don't know what to derive from this, could some please throw some light on this?

Other than the smoke for a very short span of time, there is no problem I feel in the drive, including the pull, which it does like a train when the turbo kicks in. The Smoke that it emits during the turbo phase is mainly a thick dark one, something like soot, mostly the unburnt fuel I guess.

Can some one please guide me to visually inspecting this bleed/leak? Pictures/Videos would be of great help. Thanks in advance.

My advice is, if you arnt happy with the diagnosis then take it to another garage because in order to make an acurate diagnosis it needs to be looked at by a qualified technician to avoid further damage.

Bleeding would probably put blue black smoke out.

I'd check the EGR/Pipework for being blocked up more than anything else.

In terms of the turbo itself, top the oil up to a point you know, then regularly check the oil level.

If the turbo is leaking it, you'll know pretty quickly.

Engine oil will burn quite nicely in a diesel engine so when it does finally go bang and spew oil the engine will rev uncontrollably until the whole engine goes pop.

That being said, black smoke is unburnt fuel, blue smoke engine oil and white smoke is usually water vapour.

Turbos don't leak oil by themselves, the seals in a turbo are labyrinth type, they always leak but when everything is working well they leak inwards. Meaning a small amount of exhaust and boost leaks past the turbo seals, into the centre bearing (bushing) housing where it travels down the drain to the engine crankcase and out the engine breather to be burnt with other blowby.

For turbo seals to leak outwards, the pressure needs to reverse so there is higher pressure in the engine crankcase than in the exhaust or compressor housings. Things that can cause this are a sick engine (broken/worn rings), a blocked air-fliter, blocked turbo drain or a blocked crankcase breather.

Worldwide thousands of perfectly healthy turbos are rebuilt or replaced every year because they were "leaking oil". Where actually the turbo was just a symptom of a bigger problem, fix the original problem and the turbo stops leaking.

Well, then I guess I will drive it for as long as I can. In my next scheduled service, I will get this thing inspected again, and if really required, will get it fixed (or changed).

For about 80 rupee, you will be able to pick up a new, good quality air filter.

In the UK this is supposed to be changed every 40-60,000 miles, but that's a joke and it's accepted that it should be done every 10-20,000 miles instead.

Since india can be considerably dustier than the UK, I'd suggest you get a new air filter in there every 10,000 miles (Which is easy to do yourself with just a cross head screwdriver).

In terms of the diesel smoke... well it's always buyer beware in india, but if it was me, I'd put a tank of good quality fuel in, then go out on one of the newer highways, warm the car up, then give it some beans and drive it quite hard for a little bit.

This should clear most of the cack out of the exhaust.

Otherwise it's perfectly normal for a bit of smoke under full throttle.

@ cheezemonkhai

Thanks for a great advise. I actually have been filling all my Cars from this one particular station for years, which is because this one is good with good reputation. But I guess I now need to try another one, something like SHELL and see if I still get the smoke. As a matter of fact, the Technitian at the Skoda center had also recommended changing the place from where I fill the tank and try.

By the way, we are supposed to change the Air Filter every 15,000 Kms or once a year, which ever comes first. And the cost here is actually over Rs. 800 for a good Skoda OEM Filter and not Rs. 80!

As advised by you, will hit the highway one of the coming weekends and see if things improve. I just got it serviced, new Filters, New Oil, etc, hopefully this should make a difference.

@ cheezemonkhai

Thanks for a great advise. I actually have been filling all my Cars from this one particular station for years, which is because this one is good with good reputation. But I guess I now need to try another one, something like SHELL and see if I still get the smoke. As a matter of fact, the Technitian at the Skoda center had also recommended changing the place from where I fill the tank and try.

By the way, we are supposed to change the Air Filter every 15,000 Kms or once a year, which ever comes first. And the cost here is actually over Rs. 800 for a good Skoda OEM Filter and not Rs. 80!

As advised by you, will hit the highway one of the coming weekends and see if things improve. I just got it serviced, new Filters, New Oil, etc, hopefully this should make a difference.

It would be 800Rs, I just forgot to convert from £1 to £10, oops.

Don't worry about a bit of black smoke, it's totally normal for a derv.

A diesel always runs with excess air, but as you increase the rpm, there is less time for the fuel in there to burn.

Inject more fuel and air with the turbo and eventually you'll get to the point where there just isn't enough time for the fuel to burn before it's pushed out of the exhaust valve.

Usualy a diesel is tuned so that the fueling is right to minimise this.

If you've had no problem with your fuel station, I wouldn't worry too much about changing it.

I'd just put a new air filter in yourself so you know it's been done and then go for the drive and not worry too much.

Just to add on, my Car is actually remapped. The reason I didn't mention this before was that there was this smoke even before the remapping albeit much less in quantity, hence discounted this as the source to the problem. Could this be the crux of the problem?

Just to add on, my Car is actually remapped. The reason I didn't mention this before was that there was this smoke even before the remapping albeit much less in quantity, hence discounted this as the source to the problem. Could this be the crux of the problem?

Yes.

Yes.

Then why did the chap at the Skoda Center tell me it was a leaking turbo, are they trying to rip me off???

Just to add on, my Car is actually remapped. The reason I didn't mention this before was that there was this smoke even before the remapping albeit much less in quantity, hence discounted this as the source to the problem. Could this be the crux of the problem?

Some 'remaps' are nothing more than resistors in a box that fool the ECU into delivering more fuel for the measured quantity of air available. Hence you are probably seeing unburnt fuel creating the smoke after exiting the cylinders. Not good for your turbo or cat.

Just to add on, my Car is actually remapped. The reason I didn't mention this before was that there was this smoke even before the remapping albeit much less in quantity, hence discounted this as the source to the problem. Could this be the crux of the problem?

Yes, almost certainly.

They'll probably be fuelling beyond the point where the normal map has backed off, so at higher RPM, you'll see more smoke.

If it's a puff of black you're fine, if it's just a bit at the top you're ok, if it's really thick black smoke at the top end, then you need to get them to wind back the fuelling a little bit at the top end.

Then why did the chap at the Skoda Center tell me it was a leaking turbo, are they trying to rip me off???

It's unlikely the technician knew your car was remapped.

How good a remap is depends on the knowledge and skill of the tuner altering the map. If you have black smoke then it's not a good map IMO. It's wasting fuel and probably creating dangerously hot exhaust temperatures.

It's unlikely the technician knew your car was remapped.

How good a remap is depends on the knowledge and skill of the tuner altering the map. If you have black smoke then it's not a good map IMO. It's wasting fuel and probably creating dangerously hot exhaust temperatures.

I agree, plus you're in India, where you have a land full of businessmen trying to make more money.

Was the Garage owner a Gujarati per chance

Edited 20 June, 201214 yr by cheezemonkhai

Some 'remaps' are nothing more than resistors in a box that fool the ECU into delivering more fuel for the measured quantity of air available. Hence you are probably seeing unburnt fuel creating the smoke after exiting the cylinders. Not good for your turbo or cat.

It is not a Box fitted to the Engine/ECU, but a remap of the ECU itself.

Yes, almost certainly.

They'll probably be fuelling beyond the point where the normal map has backed off, so at higher RPM, you'll see more smoke.

If it's a puff of black you're fine, if it's just a bit at the top you're ok, if it's really thick black smoke at the top end, then you need to get them to wind back the fuelling a little bit at the top end.

It's a 'puff' of black smoke, so I guess I should take it in my stride and hope for nothing is really wrong and continue with it.

It's unlikely the technician knew your car was remapped.

How good a remap is depends on the knowledge and skill of the tuner altering the map. If you have black smoke then it's not a good map IMO. It's wasting fuel and probably creating dangerously hot exhaust temperatures.

I hadn't informed the Technitian about the remap while leaving the Car for service, so he might have actually guessed the Turbo was failing since this is presumably the most common syptom when a Turbo is failing. I now really doubt if he really 'looked' at the Turbo before he confirmed to me that it had a leak!

I agree, plus you're in India, where you have a land full of businessmen trying to make more money.

Was the Garage owner a Gujarati per chance

I must agree here, they do take up every opportunity to squeeze money out of you.

LOL!!!! No, he is not a 'Gujju'!!!

Will changing the OEM Air Filter to a 'Performace' one like K&N or Pipercross, etc make a real diff? They claim to boost the air inflow by about 30% and increase the Power to about 5% (5 BHP), is this true? I would like to hear from people who have replaced their OEM with these please.

Will changing the OEM Air Filter to a 'Performace' one like K&N or Pipercross, etc make a real diff? They claim to boost the air inflow by about 30% and increase the Power to about 5% (5 BHP), is this true? I would like to hear from people who have replaced their OEM with these please.

No. The only thing aftermarket filters do is filter badly.

Clean stock filters will have an absolute minimal pressure drop. The problem is your remap is allowing the engine to inject fuel past the point where it starts to smoke. Only a better remap or a block under the accelerator will stop it.

Which car do you have? I understand the fuel quality in India is poor 92 ron? In the uk we run our petrols on 95-99 ron, im not sure if diesel is a similar story...

Will changing the OEM Air Filter to a 'Performace' one like K&N or Pipercross, etc make a real diff? They claim to boost the air inflow by about 30% and increase the Power to about 5% (5 BHP), is this true? I would like to hear from people who have replaced their OEM with these please.

I agree with the other chap here.

Leave the paper one in, it's best at stopping fine dust.

If you want to keep it performing well, just replace the paper one more often, rather than fitting a filter that flows more.

Think about it, if it flows more when dirty, then the path through it must be easier.

Easier path = higher risk of nasty fine dust in there.