[nakul0888]

I own a polo 1.6 Gt tdi. It’s about 5 years old and done 45000 kms. Lately I have noticed that under heavy acceleration in second gear the car is belching out considerable amount of black smoke. It’s very visible and I can easily see the smoke show in my rear view mirror. It’s frankly quite embarrassing. What do you guys think needs to be done here?

Also the abs light has come on. It’s the third time this has happened in the last year or so. Each time had to buy new abs sensors? What’s the deal here? How can I
fix this once and for all? Also any precautions to follow while abs light is on ??

[BigBrad]

Originally Posted by nakul0888

Also the abs light has come on. It’s the third time this has happened in the last year or so. Each time had to buy new abs sensors? What’s the deal here? How can I
fix this once and for all? Also any precautions to follow while abs light is on ??

You will see the ABS light once more even after you fix the 3rd one.

On a serious note, this is a common failure for the Polo/Vento/Rapid models. All four sensors on mine were replaced few months back. You will need to do the same and hopefully it won't repeat. If you are in Cochin, you can buy them from any of the VAG aftermarket parts shops. I bought them from a shop near Modern Bread, Edappally. Costs around 1500 bucks and you can DIY. If you still have warranty left, VW will replace it for free as it is a very well known issue. But I guess your warranty must have expired.

As for precautions, I've noticed a strange behaviour with the central auto locking mechanism with the ABS warning on the console. It keeps on locking the car even when the car is standstill and the doors are unlocked. I was once moving the car out of my house and usually park by the road (with the engine running) to lock the house gate. Just as I parked, got out and when I closed the driver door, the system auto locked. I thanked my stars as this happened right in front of my house and I could just get the duplicate key to unlock it. So do keep one of the windows open or just don't close the door. Another thing is, the car would shudder during drive and the speedo needle may fluctuate on its own. Sometimes a restart solves it, else you can keep driving in low speeds. Hope this helps.

[scorpian]

Originally Posted by nakul0888

I own a polo 1.6 Gt tdi. It’s about 5 years old and done 45000 kms. Lately I have noticed that under heavy acceleration in second gear the car is belching out considerable amount of black smoke. It’s very visible and I can easily see the smoke show in my rear view mirror.

Please have a look at the air filter first. Probably its pretty clogged amd needs a replacement.
Fuel is what i would look at next,pour in some good fuel system cleaner and that should help clear all the carbon in the system.
ABS issue is a common complaint and have seen few of my coleagues who own rapids to have repeated issues with the ABS sensors going bad.

[itwasntme]

After the air filter and fuel system cleaning, consider a engine decarb. I had a Cruze where it was recommended every 40K km.

Another thing to check is to drive it really vigorously on a highway types at high RPMs - sometimes the soot builds up in the exhaust system and can be burnt away by high RPM driving.

[clevermax]

Black smoke under heavy throttle could be because of a boost leak, get your turbo plumbing inspected.

Had seen this exact issue in my Punto recently. Wide open throttle run produced enough black smoke to blind anyone behind.

[SS-Traveller]

Originally Posted by nakul0888

...the car is belching out considerable amount of black smoke. It’s very visible and I can easily see the smoke show in my rear view mirror. It’s frankly quite embarrassing. What do you guys think needs to be done here?

Black smoke on hard acceleration can have multiple reasons:
1. Stuck EGR valve;
2. Failed piston oil control ring;
3. Leaking turbo oil seal;
4. Choked air filter;
5. Contaminated diesel fuel;
6. Leaking valve guides;
7. Poor compression in one or more cylinders.

You'll need to check and eliminate the reason(s) one by one with the help of a good FNG - otherwise your authorized service centre would straight away advise an engine rebuild.

Originally Posted by nakul0888

Also the abs light has come on. It’s the third time this has happened in the last year or so. Each time had to buy new abs sensors? What’s the deal here? How can I fix this once and for all? Also any precautions to follow while abs light is on ??

Does the ABS light come on after driving in mud & slush? Does your car have an ABS sensor-based TPMS?

[dhanushs]

The MAF sensor will rule out a dirty air cleaner. Though worth a check.

My bet would be on the turbo/plumbing. Since EGR errors are infamous in VW and vehicle would go to limp mode.

That said, nowadays the numerous sensors do prevent the car from smoking even if you have less air coming in, by reducing the fuelling.

So, is your car remapped?

[nakul0888]

Originally Posted by SS-Traveller

Black smoke on hard acceleration can have multiple reasons:
1. Stuck EGR valve;
2. Failed piston oil control ring;
3. Leaking turbo oil seal;
4. Choked air filter;
5. Contaminated diesel fuel;
6. Leaking valve guides;
7. Poor compression in one or more cylinders.

You'll need to check and eliminate the reason(s) one by one with the help of a good FNG - otherwise your authorized service centre would straight away advise an engine rebuild.


Does the ABS light come on after driving in mud & slush? Does your car have an ABS sensor-based TPMS?

Damn, hoping its not really serious. There is no impact on performance though. Car seems to be running fine and there is no check engine light. Its just that now and again when I floor the pedal to do a quick pull it coughs up black smoke like a KSRTC Bus.

No I dont have any TPMS installed. Mine is a 2013 car. Not much gizmos on it.

Originally Posted by dhanushs

The MAF sensor will rule out a dirty air cleaner. Though worth a check.

My bet would be on the turbo/plumbing. Since EGR errors are infamous in VW and vehicle would go to limp mode.

That said, nowadays the numerous sensors do prevent the car from smoking even if you have less air coming in, by reducing the fuelling.

So, is your car remapped?

The car performs fine. Its just belches out black smoke under hard acceleration. Not all the time, just under hard acceleration.

The car is completely stock. Though I do have a Remap on my mind.

[Dr.Naren]

A friend was facing excessive black smoke issue in his S-Cross 1.6 and I had checked the service manual for troubleshooting. This should be applicable to any modern diesel car

1. Preliminary Check

• Check that engine oil level is correct

• Check that air intake / turbocharger circuit is working properly

• Check that main and circuit fuses have not blown.

2. Environmental Parameter Check

• Battery Voltage
• Barometric Pressure

• Fuel Temperature

• EGR Valve opening

3. Low Fuel Pressure Circuit Check

4. High Fuel Pressure Circuit Check

5. Inlet throttle Valve Operation Check ( Yes it's present even in VAG 1.6 TDI )

6. Glow Plug Control Module Check

7. A/F Sensor Check

8. Timing Check

9. Turbocharger System Check

I would suggest you to check air intake , EGR and Turbo. If it's not resolved, you may proceed with the rest.

Cheers!

[NTO]

Originally Posted by nakul0888

I own a polo 1.6 Gt tdi. It’s about 5 years old and done 45000 kms. Lately I have noticed that under heavy acceleration in second gear the car is belching out considerable amount of black smoke. It’s very visible and I can easily see the smoke show in my rear view mirror. It’s frankly quite embarrassing. What do you guys think needs to be done here?

Also the abs light has come on. It’s the third time this has happened in the last year or so. Each time had to buy new abs sensors? What’s the deal here? How can I
fix this once and for all? Also any precautions to follow while abs light is on ??

Black smoke is common under heavy accelaration in second gear in 1.6 TDis. My Vento does it too and I have noticed it many times. I have validated the same with a couple of others with 1.6 TDis (A GT, a Vento and a Rapid). Nothing much to worry there. I believe you should've just started to notice. A word of relief "We literally smoke the vehicles we overtake"

ABS sensor failure is common and will fail one after the other. I was lucky to get them all failed and replaced under warranty. These are readily available in after market VAG part shops between Rs. 1000 and Rs. 1500.

[rvd8732]

Agreed with NTO. Diesel cars tend to emit smoke during heavy acceleration and it happens with my 1-year-old Toyota Plantimum ETIOS Limited Edition.

[dhanushs]

Originally Posted by NTO

Black smoke is common under heavy accelaration in second gear in 1.6 TDis. My Vento does it too and I have noticed it many times. I have validated the same with a couple of others with 1.6 TDis (A GT, a Vento and a Rapid). Nothing much to worry there. I believe you should've just started to notice. A word of relief "We literally smoke the vehicles we overtake" .

Well, I’ve had two Ventos. One sold at 53,000 and the current one running 73,000. Both 1.6 TDi and both don’t smoke.

The earlier one was remapped. Still didn’t smoke.

[speedmunster]

Get the EGR cleaned. I had the same issue with my 2006 Fiesta. After the EGR cleaning, the black smoke reduced considerably. In fact this reminds me, I need to get the EGR cleaned again as almost 46000 kms have been run after the last cleaning.

[Viraat13]

Originally Posted by nakul0888

I own a polo 1.6 Gt tdi. It’s about 5 years old and done 45000 kms. Lately I have noticed that under heavy acceleration in second gear the car is belching out considerable amount of black smoke. It’s very visible and I can easily see the smoke show in my rear view mirror. It’s frankly quite embarrassing. What do you guys think needs to be done here?

Also the abs light has come on. It’s the third time this has happened in the last year or so. Each time had to buy new abs sensors? What’s the deal here? How can I
fix this once and for all? Also any precautions to follow while abs light is on ??

So here is the thing, black smoke can be because of a number of reasons, such as a clogged air filter, poor quality of fuel, etc. The most likely suspect is a dirty EGR valve. You should visit a competent FNG, or such, and get the turbo plumbing and EGR valve cleaned out. I find that if you don't idle the car for a minute after a drive, the EGR gets dirty pretty quickly.

Once you've got the EGR valve and turbo pipes cleaned up, regularly practice the "Italian tune-up". If you're not familiar, google will give you way more info.

After I got the EGR cleaned on my Octavia 1.9 TDI at 55K km, I practiced the idling before switching off rule (along with a very regular Italian tune-up), and the EGR didn't get even 1 mm of soot in over 70K kms.

You may get recommendations for doing engine decarb, but I would advise you to avoid the same. While 45K is not very high mileage, decarb could negatively affect the engine health on high mileage cars.

[arjab]

Got my friend's Skoda Rapid Diesel cleaned up as it was exhibiting the same symptoms.
Its a very common thing in VW Polo's , Vento's Skoda Rapid Diesel's, or for that matter, most diesel models running in India, and having covered over 50k kilometres.

Remedy:
1. Disassemble and clean the entire EGR assembly in the good old fashioned way with a oodles of kerosene. Refit.
2. Open the entire exhaust assembly , right from the front flange , immediately after the exhaust manifold, up to the tail pipe. Separate all the sections. Ask your service centre to blow compressed air through all the opened sections, multiple number of times , through both ends. You'll be amazed at the clouds of soot that billow out !

After all this refit everything and check. There'll be practically "no smoking" . Smoking will start after soot build up starts again , typically after 10k kilometres, when you can repeat the process again.