Go Back   Team-BHP > Under the Hood > Technical Stuff


Reply
 
Thread Tools Search this Thread
Old 27th June 2017, 22:26   #16
Newbie
 
Join Date: Jul 2016
Location: Navi Mumbai
Posts: 19
Thanked: 17 Times
Default Re: Solved: VW Polo GT TSI power drop after service! It was the air filter

I checked the service invoice for all 3 services done so far and the part used is 6RF129620 in all of them. I have no idea what was the original part used before the first service so that's that.
But you have piqued my interest on the topic so maybe I'll give the K&N filter a try once I go for the next check-up.
Thanks again for sharing your experience.
razer2911 is offline   Reply With Quote
Old 27th June 2017, 23:47   #17
BHPian
 
shinuak's Avatar
 
Join Date: May 2013
Location: Bangalore / Tvm
Posts: 140
Thanked: 68 Times
Default Re: Solved: VW Polo GT TSI power drop after service! It was the air filter

Avinash, Is it the same filter which is used in Skoda Rapid 1.5/1.6 TDI ? If so you can check for OTC sale of this part from any Skoda ASS. I will try to figure out the part number from my manual and PM you if that is the case. Let us see if the siblings have this part in common
shinuak is offline   Reply With Quote
Old 27th June 2017, 23:54   #18
BHPian
 
Join Date: Apr 2010
Location: Delhi
Posts: 225
Thanked: 102 Times
Default

Interesting thread indeed.

I feel lucky to have kept the filter and to have found it in the junk I keep to discard to my friendly neighborhood raddi guy and the fact that I haven't called him in since my last service.

But more​ about it only when I check the part number first thing in the morning tomorrow.

Though I don't think my GT tsi is showing these symptoms, or is it?
LithiumSunset is online now   Reply With Quote
Old 28th June 2017, 04:50   #19
BHPian
 
AMG Power's Avatar
 
Join Date: Mar 2017
Location: Bangalore
Posts: 94
Thanked: 302 Times
Default Re: Solved: VW Polo GT TSI power drop after service! It was the air filter

Sorry, but have to completely disagree with the OP.

This is not a case for generalisation. If it were so, there would have been several such instances. Lumax filters for VW cars have been around for several years.

Even on this thread there are others who have had Lumax fixed on their cars everal times with no apparent drop in volumetric efficiency.

This is just a one off case and maybe the specific air filter had a manufacturing defect or was not fixed properly.

There is no cause for others to be worried if they don't have a problem.

Last edited by AMG Power : 28th June 2017 at 04:52.
AMG Power is offline   (2) Thanks Reply With Quote
Old 28th June 2017, 09:37   #20
BHPian
 
Join Date: Mar 2017
Location: Panchkula
Posts: 37
Thanked: 37 Times
Default Re: Solved: VW Polo GT TSI power drop after service! It was the air filter

Quote:
Originally Posted by AMG Power View Post
Sorry, but have to completely disagree with the OP.

This is just a one off case and maybe the specific air filter had a manufacturing defect or was not fixed properly.

There is no cause for others to be worried if they don't have a problem.
Maybe and maybe not. But it does induce a certain amount of apprehension in the minds of GT owners. The OP has done yeoman service in bringing this up in the forum. Now it needs to be taken up with VW to give the necessary clarification and " all clear " signal to their car owners. In the interim, it is better to be safe rather than sorry.
Cheers.
vkr15 is online now   Reply With Quote
Old 28th June 2017, 11:51   #21
BHPian
 
Join Date: Jun 2014
Location: Bangalore
Posts: 363
Thanked: 346 Times
Infractions: 0/1 (5)
Default Re: Solved: VW Polo GT TSI power drop after service! It was the air filter

Great you got it fixed and now you are happy with your car.

Sorry for going a bit OT, but you said there was another car, which was driven(By you or the rep), this is a bit surprising for me. It was some one else car that you/rep drove which was in the bay for servicing, had anything happened to the car who would have taken responsibility. If i had got to know that my car has been driven without my permission, i would have been extremely furious.
AtheK is offline   (2) Thanks Reply With Quote
Old 28th June 2017, 13:29   #22
BHPian
 
Paleo's Avatar
 
Join Date: Aug 2009
Location: Pune
Posts: 61
Thanked: 20 Times
Default Re: Solved: VW Polo GT TSI power drop after service! It was the air filter

Quote:
Originally Posted by AtheK View Post
Great you got it fixed and now you are happy with your car.

Sorry for going a bit OT, but you said there was another car, which was driven(By you or the rep), this is a bit surprising for me. It was some one else car that you/rep drove which was in the bay for servicing, had anything happened to the car who would have taken responsibility. If i had got to know that my car has been driven without my permission, i would have been extremely furious.
Agree Completely! To me, the LUMAX filter could have been a one off issue. They arent substandard to be genralizing, according to me. The bigger issue was the SC giving someone else's car for a test drive. Definitely unacceptable!

As a side note - Had recently gone with a friend to a FORD dealer in Pune. She test drove Ecosport Manual and AT. Neither of them were Demo Cars. Clearly Temp registered and waiting for delivery. When asked, the guy just smiled and said, "just a few kms sir" !
Paleo is offline   (1) Thanks Reply With Quote
Old 28th June 2017, 15:15   #23
BHPian
 
Join Date: Dec 2015
Location: India
Posts: 214
Thanked: 155 Times
Default Re: Solved: VW Polo GT TSI power drop after service! It was the air filter

Regarding the quality of Lumax air filters, it is highly likely that they are not up to the mark as the UFI ones.

Some of VW India's other localized components are known to be substandard, right from the external finish of the components to the service life, which is like 1/3rd of the service life of the global counterparts (and even lesser than 1/3rd for me).
halfbytecode is offline   Reply With Quote
Old 28th June 2017, 18:36   #24
Senior - BHPian
 
Join Date: Oct 2012
Location: Delhi
Posts: 2,990
Thanked: 5,926 Times
Default Re: Solved: VW Polo GT TSI power drop after service! It was the air filter

I have been following this thread and the title suggest that the root cause of the problem was identified as the air filter. Based on the information presented, I’m not convinced though. Let me explain:

A clogged air filter can have significant impact on a car’s performance. I find it difficult to image to that a brand new filter, no matter how crappy, would have such an impact on the car’s performance. There is no way that is caused by just a crappy filter that might have a bit more resistance compared to a new, proper, filter.

So unless this new, crappy, filter had some serious defects or was installed in such a way that the rubber seal was pulled off and blocked the air inlet or it had some serious manufacturing defect, I don’t see how it could have impacted the engine performance this much.

The easiest way to verify is to put this filter back on and see if the problem returns. That would prove beyond doubt it was actually the filter. Otherwise, I find this cause not very plausible.

some thoughts/comments on some of the details and information provided:

Quote:
He got the UFI filter blowed, to remove black soot particles, removed the Lumax and installed UFI, ran diagnostics, updated some Software (apparently he said).
This is the problem why the story and pointing to the filter as the root cause is not plausible. Several different items where changed all at once. We are not quite sure what or how. But afterwards everything was fine, so why was the filter the culprit?

If you want to do a proper fault analysis you need to take it one step at a time, or you will never know the real problem.

A few other thoughts/comments:

Quote:
From 0-2.5K RPM there was sluggish acceleration and very less torque, glaringly experienced on inclined roads, and after that, a sudden torque surge, and rpm used to shoot up till 4K.
This doesn’t seem to be consistent with an air filter being clogged or reduced air flow. If anything at low revs a clogged filter will perform relatively better than at high revs. Less air to go through, less resistance relatively speaking

Quote:
Check out the thickness of the fibre layering on the outer surface. Its common sense, that the thicker the filter, the less the air that gets in. The design of air filter is a thin line of art.
Yes, but on a new clean filter the thickness won’t make a huge difference, at least not to the extent you noticed on engine performance. To see such degradation it needs to have a substantial higher resistance than a normal proper filter.

Quote:
Since my car had done 7.5K, there was 7.5K life left in the UFI filter.
NO, absolutely not! Filter life has not necessarily to do with how many km you do. (even though your manual will say so, its based on averages. Especially in India with many very dusty places a filter could get clogged within a few hundred kilometers, less if you find yourself driving on very dusty roads.

(Once I had my Royal Enfield bullet serviced, changed the filter. We found ourselves driving on a sand road with some 30 bikes, in a huge sand cloud for about 10km. Several of us, including mine stalled due the (new) air filter completely clogged up with hardly any miles on it.)

Quote:
Since the torque in those cars is more, the little reduction in airflow will result in marginal reduction in power, sometimes which can go unnoticed. But surely an analysis of Mass Air flow should throw up the issues on the result sheets
Don’t think so. Torque is a function (a.o.) of how much fuel and air gets injected. What would you like to analyse from the MAF? If you want to do a measurement you would have to find a way to measure pressure drop across the filter. Which on a non turbo car could be achieved by looking at inlet air pressure against atmospheric pressure. Change the filters out and see if you get a noticeable difference. Easier is what I suggested earlier, just swap the filter back and see if the problem returns.

So I am not convinced at all that the filter was the culprit. There are too many contradictions, things don’t add up and I see no evidence of a thorough methodically step by step trouble shoot approach. So to blame it on the air filter, in my opinion, is pre-mature or at least not proven at all.

do you still have that crappy filter? If so, stick it on and see what happens. If it does impact the engine performance immediately and substantially, cut it open, because I find it very difficult to imagine that the thickness of the mould alone can cause this effect.

Jeroen

Last edited by Jeroen : 28th June 2017 at 18:38.
Jeroen is offline   (5) Thanks Reply With Quote
Old 28th June 2017, 21:50   #25
BHPian
 
Join Date: Apr 2010
Location: Delhi
Posts: 225
Thanked: 102 Times
Default

Quote:
Originally Posted by LithiumSunset View Post
Interesting thread indeed.

I feel lucky to have kept the filter and to have found it in the junk I keep to discard to my friendly neighborhood raddi guy and the fact that I haven't called him in since my last service.

But more​ about it only when I check the part number first thing in the morning tomorrow.

Though I don't think my GT tsi is showing these symptoms, or is it?
Confirmed. The replacement filter is Indeed a diesel engine filter. Now this means that for the two services I've had the same part was replaced both times.

So this is common practice, it seems.

But, I'll be honest here, I don't think my GT shows any drop in power. So based on the comments that have followed (from Jeroen and others) I do think OP's problem must've had other reasons. Time for someone from the VW to clarify. (Am I kidding myself, as if someone from VW is actually going to be reading this thread).
Attached Thumbnails
Solved: VW Polo GT TSI power drop after service! It was the air filter-1498666017755.jpg  

LithiumSunset is online now   (1) Thanks Reply With Quote
Old 28th June 2017, 22:12   #26
Senior - BHPian
 
Join Date: Oct 2012
Location: Delhi
Posts: 2,990
Thanked: 5,926 Times
Default Solved: VW Polo GT TSI power drop after service! It was the air filter

There is a suggestion in this thread that air filters for Diesel engines are different from those for petrol engines. Now as the air/fuel ratio is somewhat different for a diesel compared to a petrol. But still, could somebody elaborate on the differences between a 'diesel' and a 'petrol' filter? Sheer Size springs to mind, but nothing else. I don't see a huge problem interchanging these.

Jeroen

Last edited by Jeroen : 28th June 2017 at 22:14.
Jeroen is offline   Reply With Quote
Old 29th June 2017, 11:19   #27
BHPian
 
AMG Power's Avatar
 
Join Date: Mar 2017
Location: Bangalore
Posts: 94
Thanked: 302 Times
Default Re: Solved: VW Polo GT TSI power drop after service! It was the air filter

Quote:
Originally Posted by avanishphatak View Post

The same air filter is used in the Vento diesel and Vento 1.6.
The filter in the Vento diesel and Vento 1.6 are NOT the same.

Quote:
Originally Posted by avanishphatak View Post

Since the torque in those cars is more, the little reduction in airflow will result in marginal reduction in power, sometimes which can go unnoticed.

Its actually the exact opposite of what you've written.

Torque of Vento 1.6 = 153Nm @ 3800 rpm
Torque of Polo GT TSI = 175Nm @ 1500 rpm.

Last edited by AMG Power : 29th June 2017 at 11:30.
AMG Power is offline   Reply With Quote
Old 29th June 2017, 13:59   #28
BHPian
 
avanishphatak's Avatar
 
Join Date: Mar 2007
Location: bangalore
Posts: 66
Thanked: 155 Times
Default Re: Solved: VW Polo GT TSI power drop after service! It was the air filter

Quote:
Originally Posted by redcruiser View Post
I am glad that you are now a happy customer. But as you figured out the issue it may not be the same case for others. You should write to the higher management of VW.

Everyone doesn't check the brand of AirFilter used after every service.
Yes redcruiser. I have written to them. They caleld me and will respond during the week is what they said. I'l update here as an when information flows.

Quote:
Originally Posted by halfbytecode View Post
This was really informative about the air filter. I really appreciate the details you have provided.

These Germans are complex cars, with two cars manufactured one after the other, still having different parts, even if the cars are of the same trim.
Thanks halfbytecode. This is informative.

Quote:
Originally Posted by razer2911 View Post
I doubt if it would be possible to source the UFI filter easily but how about K&N filters? They sure are expensive but apparently, they last 50K miles (or 50K kilometers considering Indian conditions).
Thanks razer2911. I did have a K&N on my swift 1'3L petrol. There was noticeable difference in engine performance. I'm open to having it in GT-TSI too but of course that depends, whether if VW will honor warranty for 3rd party filters.

Quote:
Originally Posted by shinuak View Post
Avinash, Is it the same filter which is used in Skoda Rapid 1.5/1.6 TDI ? If so you can check for OTC sale of this part from any Skoda ASS. I will try to figure out the part number from my manual and PM you if that is the case. Let us see if the siblings have this part in common
Can anyone on this forum who own a Skoda share us some info, would be helpful.

Quote:
Originally Posted by LithiumSunset View Post
Interesting thread indeed.

Though I don't think my GT tsi is showing these symptoms, or is it?
Lucky you have it stored somewhere LithiumSunset. if you find some time, please can you test it with the UFI and let know the results? that way we will be able to make-out if this is a one off case or not.

Quote:
Originally Posted by AMG Power View Post
The filter in the Vento diesel and Vento 1.6 are NOT the same.

Torque of Vento 1.6 = 153Nm @ 3800 rpm
Torque of Polo GT TSI = 175Nm @ 1500 rpm.
AMG Power, the box sticker says 1.6 diesel filter. and the 1.6 diesel has about 250nm@2500rpm torque when I checked. Was that numbers for petrol? Please correct me if I'm wrong.

Quote:
Originally Posted by Jeroen View Post

The easiest way to verify is to put this filter back on and see if the problem returns. That would prove beyond doubt it was actually the filter. Otherwise, I find this cause not very plausible.

This is the problem why the story and pointing to the filter as the root cause is not plausible. Several different items where changed all at once. We are not quite sure what or how. But afterwards everything was fine, so why was the filter the culprit?

If you want to do a proper fault analysis you need to take it one step at a time, or you will never know the real problem.

Jeroen
i did that Jeroen. We put back the old filter. Same SW version. Same DSG sw, same state of the car. I can see the difference.

Would love to do a roadtest with a co GT-TSI owner using UFI and Lumax filter. That way we can start to eliminate variables and come to a reasonable opinion on what could be the root cause.
avanishphatak is offline   Reply With Quote
Old 29th June 2017, 16:29   #29
Distinguished - BHPian
 
hemanth.anand's Avatar
 
Join Date: Jan 2010
Location: Bengaluru
Posts: 2,098
Thanked: 5,697 Times
Default Re: Solved: VW Polo GT TSI power drop after service! It was the air filter

Quote:
Originally Posted by avanishphatak View Post
[b]For instance, if the part number is 6RO-129-620-A , the upgraded part number could be 6RO-129-620-B and not a radical change to a completely new numbering structure 6RF-129-620. This is because the format of the part number is based on location_of_the_part-enginetype etc. So unless engine type and location of the part changes, there will be only incremental upgrades.

The factory fitted air filter in the car was made by UFI with part number: 6RO-129-620-A made in Tunisia. Costs 18-26$ approx across the world.

The one installed in the car was an air filter made by Lumax with part number 6RF129620 Made in India (Pune). Costs 396/- Pre GST inclusive of VAT. As on mid June 2017
Yes all part numbers starting with 6RF are made in India. And that's one of the biggest reasons for cost reduction.
Quote:

Above are the pictures of both. The UFI and Lumax. What I observed is that the quality of the two air filters was very different. The UFI was of much better quality than the Lumax. The mould quality of the Lumax is crap. The injection moulding remnants, the overly thick outer fibre.
Attachment 1651268

It looks much worse than a local air filter available in places in SP Road. I’ve seen Maruti Air filters. They are of far better quality than this one. This is just plain substandard.
The mould marks are all neither functional nor cosmetic. so quality of these won't be strictly controlled

Quote:
Check out the thickness of the fibre layering on the outer surface. Its common sense, that the thicker the filter, the less the air that gets in. The design of air filter is a thin line of art. One has to get most particulate matter filtered without hampering the density of air. Its like a skirt design, shouldn't be too high nor too low which will mar the intent.
Thickness wise,I don't see much of a difference in terms of the actual thickness. of course the edges are not as neat as the other one in the picture. but that is used for some duration and this is completely new. Design of air filter is an art I agree, but modern cars are not that simple that a slightly thicker filter material will result in noticeable performance change of the car. Thicker material will reduce the efficiency of the filter but not the performance of the car. MAF sensor, Intake manifold, throttle body, ECU all work together to control the airflow. If there is more demand from the cylinder and the MAF sensor detects less supply due to a less efficient air filter, ECU will adjust the throttle valve to allow more air to be sucked in and maintain the required air pressure in the intake manifold.

Quote:
1. The Vendor (Lumax makes crap air filters for VW) doesn't know how they got through the apparently claimed German standard quality check
It is not that easy to pass through the standards

Quote:
2. Cost of filter is 396/-. For someone buying a GT, even 800/- per air filter is ok, but not substandard quality
Low cost doesn't always mean low standards. localization, higher tolerance for non-functional, non-cosmetic areas will all have reduced the costs
Quote:
3. Surprised that the same airfilter is used for petrol and diesel.
It can be used if requirements are similar

Quote:
5. They have the assumption that whatever spares that arrive from the company are perfect fit. “sir Volkswagen has approved. They will have done all testing”
Don't you think they would've done all the necessary tests?


Quote:
Originally Posted by AtheK View Post
If i had got to know that my car has been driven without my permission, i would have been extremely furious.
True that, that's exactly why I asked the following question because my car was there in the same service station approximately around the same time
Quote:
Originally Posted by hemanth.anand View Post
Would you be kind enough let me know more details of this car that you test drove.
But had he not test driven, there would be no reference point. In the long run it may help everyone. Tricky topic though and completely understand you.
hemanth.anand is offline   (1) Thanks Reply With Quote
Old 29th June 2017, 16:36   #30
BHPian
 
Join Date: Jun 2014
Location: Bangalore
Posts: 363
Thanked: 346 Times
Infractions: 0/1 (5)
Default Re: Solved: VW Polo GT TSI power drop after service! It was the air filter

Quote:
Originally Posted by hemanth.anand View Post



True that, that's exactly why I asked the following question because my car was there in the same service station approximately around the same time

But had he not test driven, there would be no reference point. In the long run it may help everyone. Tricky topic though and completely understand you.
At least i would want some one to call me and ask my permission, yes it might be for the greater good, but at the same time some one else(Perhaps a biker), could have scratched/damaged the car, it would have been a very tricky situation then.

Probably a better idea would have been to first try driving the Test drive car. Ultimately it is the experience in the TD vehicle(With which ever air filter it is fitted at that time), that makes us buy our own in the first place.

Just my two cents.

Last edited by AtheK : 29th June 2017 at 16:39.
AtheK is offline   (1) Thanks Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Ikon Fuel Filter : OEM is cheaper than After-Market filter RM2488 Technical Stuff 13 28th June 2012 11:39
Palio - Petrol emitting black smoke after service. And SOLVED too! junkishya Technical Stuff 5 28th February 2011 14:09
Air filter and Air intake sunilvarma Technical Stuff 10 4th November 2010 10:58
Air Filter - Power v/s FE KSM-Vtec Modifications & Accessories 24 29th September 2008 12:32
Best air filter or cold air intake for Skoda RS Kartik9500 Modifications & Accessories 9 7th February 2008 03:43


All times are GMT +5.5. The time now is 13:04.

Copyright ©2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks