[dinu2506]

Dear friends,
I keep getting this issue each time I go for emission checking for my Audi A4 Diesel 35TDI 2016 and my BMW X1 sDrive 20D 2013 both BS4. Its a pain when the sensor does not give proper readings. They keep experimenting at various locations on the engine bay and sometimes it works. Last time I took a photo of where it worked. It was on one of the alternator mounting bolts. Today I had the same issue and made him use the same place, but this time it did not work. Removed the engine cover and tried on the top of the injectors (where it works for my BMW x1). Went to two different places to no avail. Mostly the error is that the rpm is not within limits. On top of it, they give gyan like BMW and Audi does not emit much smoke to detect, the car generates too much horsepower etc etc. And this is not recent, it has always been a pain from the time it was new. Getting fed up now.

I'm assuming this is faced by many. Any help on this matter will be appreciated for both the Audi and BMW Diesels.

Thanks in advance

[vinay.sathyan]

I really thought I was the only one facing this problem, mine is a GLC220d.
Firstly finding diesel emission test centers is difficult enough and then this.

My first experience was horrible, he was raising the rpm on the car so much since he was not getting any reading and I felt horrible seeing that happen to my car. But my 2nd visit, there was another guy and i must say he didn't do everything thing legally to my knowledge, but he did generate the certificate without much hassle. if its close by, do visit this guy.

https://goo.gl/maps/eyCxppnpg5PBuLnL8

PS: Please give him a call before visiting, they tend to take long leaves during holiday seasons.
Let me know how it goes.

Also if it helps, this is a list of diesel pollution testing centers I noted in Bangalore, some are verified some are not. Please call ahead and then visit.

https://goo.gl/maps/TM8HKfQPLGLz5CDh9

[dinu2506]

Thank you. The curious thing is that in these same places, all the Japanese and Korean diesels happily come, test and go without any hassle. Wonder what’s different with the Germans? Highly irritating

[Jeroen]

Originally Posted by dinu2506

Its a pain when the sensor does not give proper readings. They keep experimenting at various locations on the engine bay and sometimes it works. Last time I took a photo of where it worked. It was on one of the alternator mounting bolts. T

I am trying to understand what is going on here. Which sensor is giving an incorrect reading. Do you mean they try to attach something to pick up the RPMs.
(Not sure what signal you can pick up from an alternator mounting bolt, one would hope none! )

Jeroen

[dinu2506]

Originally Posted by Jeroen

I am trying to understand what is going on here. Which sensor is giving an incorrect reading. Do you mean they try to attach something to pick up the RPMs.
(Not sure what signal you can pick up from an alternator mounting bolt, one would hope none! )

Jeroen

Yes, the sensor that picks up the RPM. This is where it was placed last time around and worked after many trials. Did not work this time

[ajmat]

I have no problem with the Q3 at Sai Service Station Kasturba Road, next to the Museum

[condor]

I face a similar issue on my 2013 Safari Storme. This has happened at the same testing centre at least twice in a row now, and I need to idle and run the engine at least 10 minutes before the test comes out successful. The issue wasnot there earlier, which was done at other testing centres. Hence plan to go to a different place next time.

However, if any suggestions to avoid this are posted, would be happy to try it out.

[dinu2506]

Happy to report that I got both the cars done now in a jiffy at another place. Seems to be a new system where they only connect their leads to the positive and negative of the battery. No tail pipe input as well. Then a mobile app that does the same series of Idle and Race a few times. Then it gives the results. Both cars passed with flying colours.
Recommendation - Avoid the places with the old technology of rpm sensor and tail pipe tube.

Hope this helps. I’m breathing a sigh of relief

[superbad]

An ultra noob question : if it's puc, why isn't it through the exhaust pipe?

[aamishdhingra]

Originally Posted by superbad

An ultra noob question : if it's puc, why isn't it through the exhaust pipe?

Usually the PUC is done via the exhaust pipe, and the RPM in consonance in order to check the emissions in a more controlled manner.

[superbad]

Originally Posted by aamishdhingra

Usually the PUC is done via the exhaust pipe, and the RPM in consonance in order to check the emissions in a more controlled manner.

I've only seen tail pipe emissions being checked. Have never seen any other test being conducted for PUC, nor done for any of my vehicles. Is the rpm test done only for high end diesel vehicles?

[kiranton]

I have also faced similar issue on my 320d couple times. You really feel bad when they rev the engine hard to get a reading, but don't get any. Both times, they gave me PUC with some jugaad and not the real reading.

[kiran_cr]

I too got PUC checked for my Innova Crysta 2.8Z yesterday. The RPM sensor lead was just placed on the engine casing just below the engine cover. Test was done only with RPM values and not tail pipe exhaust. When I enquired with the person, he mentioned that the current regulation for Diesel vehicles mandates only RPM test and exhaust is not required. Apparently they can check if the vehicle's pollutants are within range or not based on the engine vibration and rpm. Im not sure of the technicalities here, can anyone throw light on this topic please?

[steadfast]

Ae error with VW cars as well. The problem is that these cars on neutral do not reach high RPMs as a way to prevent any possible engine damage. In other cars we are able to red line even on neutral.

So seems all German Engines have this protection mechanism and hence a chalenge for PUC.

[dinu2506]

Originally Posted by superbad

An ultra noob question : if it's puc, why isn't it through the exhaust pipe?

Not a noob question. I too was curious to know how the emissions are measured without measuring the tail pipe emissions. Surely its some calculation based on RPM. Was just happy that the ordeal was over and got a clean chit

Originally Posted by superbad

I've only seen tail pipe emissions being checked. Have never seen any other test being conducted for PUC, nor done for any of my vehicles. Is the rpm test done only for high end diesel vehicles?

In the place I went, all diesels were tested in a similar way. No discrimination

Originally Posted by kiranton

I have also faced similar issue on my 320d couple times. You really feel bad when they rev the engine hard to get a reading, but don't get any. Both times, they gave me PUC with some jugaad and not the real reading.

Locate a center where they connect their leads to the battery terminals and not using a rpm sensor inside the engine bay, which apparently is an older method. And this exactly was the Achilles heel for me that the readings were not proper, and made me open this thread

Originally Posted by kiran_cr

I too got PUC checked for my Innova Crysta 2.8Z yesterday. The RPM sensor lead was just placed on the engine casing just below the engine cover. Test was done only with RPM values and not tail pipe exhaust. When I enquired with the person, he mentioned that the current regulation for Diesel vehicles mandates only RPM test and exhaust is not required. Apparently they can check if the vehicle's pollutants are within range or not based on the engine vibration and rpm. Im not sure of the technicalities here, can anyone throw light on this topic please?

I've seen most Japanese engines able to go through with this method. This was the intent of the post that I was not able to get proper readings for my cars. The technology with connection to the battery terminals worked like a charm in the first trial itself.

Now that my problem is solved, I'm still looking forward to anyone who could explain in layman terms how the emission values are calculated with just a rpm sensor or a connection to battery. Still foxes me.

For people in Bangalore, this is where I got it done. Might come in handy for you
https://goo.gl/maps/zJs8whuBw4F1Kgap8