Hi,

I have a Polo 1.6 tdi (2012 model) with around 85k on the clock. Engine code is also CLN and not CAY.
For the past 2-3 years I have complained to VW when servicing the car that the sound more diesely than usual and is not making the power is suppose to be. Its only really noisy on certain load's (eg low rpms high load, sometimes cruising on the highway (+- 110)
The trip pc's reported fuel consumption is quite heavy.
I have since also realised that fuel consumption per tank is around 5 l/100kms actual while the trip pc reports in the range of 6-7.
People I have talked to about this also told me to check if the fault codes and sensor readings. The car doesn't have any fault codes and but the throttle sensor stays constant at 88.6 according to my wifi obd sensor. VW did tell me the sensor is working correctly on their equipment thou.

So after taking it back to VW specifically for this, they told me its my injectors. Apparently their variance is fine during idle, but when driving and under load they go a bit out of bounds.

I have a few questions regarding this:
Can this actually be injectors thats causing this, 85K feels a bit quick for then to break, although this has been going for about 2-3 years so its actually a good few km's less (probably around 40k)
The VW mechanic told me I could put an aftermarket chip on this to more finely control the injectors to reduce the high variance, is this a viable tactic?
Could it be something else that I could look at? Replacing injectors isnt something that I want to do if I dont as they dont come in cheap...

Thanks

Blackwolfsa wrote: ↑Mon Nov 05, 2018 3:35 pm The VW mechanic told me I could put an aftermarket chip on this to more finely control the injectors to reduce the high variance, is this a viable tactic?
Could it be something else that I could look at? Replacing injectors isnt something that I want to do if I dont as they dont come in cheap...

Thanks

This statement does not make sense and VW are giving you a crap story.
I suggest go to another VW dealership to assist youor if you some funds ask one of the guys to check out the car for i.e Panic Mechanic.

You cannot fi injectors out of spec with mapping or chipping. It;s a mechanical wear issue.
Get an opinion form somebody else than that guy.
Sadly you supply no location so cannot recommend anybody.

Start with the basics.

Change the air and diesel filter.

I am in Pretoria region.

Dont think they could diesel/air filter as they where replaced earlier in the year with normal service and the issue has persisted longer than that.

Hi,

I have the same 1.6 TDI (2011) CLN engine spec, Its is also very noisy. I am doing over 200k Kms, When I purchased the Car at 150K kms its was also very noisy and the car dealer then replaced 2 injectors, It didn't really make a difference.They also showed me another same spec car that was also noisy and i resigned to these engines being rowdy. I've since done 50 000+ with no issues,

The noise is very distinct mainly between 1000 to 2000 revs sounds like the lifters are badly stuck, Its quite a huge knocking/ tapping sound Very annoying especially when driving in quite times or in closed areas like parkades..etc..

I have even made a point to try and take note of other Polo tdis and most sound noisy. I have also taken the car to a workshop and requested to replace the lifters, The mechanic advised me its a waste of time as these cars are noisy, Apparently VW has a Factory note (something to do with Head pressure or injector pressure that makes it noisy)no solution to the problem.

I must say the car has pretty much given me good service besides being noisy and minor acceptable wear and tear, The power is still decent , could be more economical on diesel, however does the job i need it to as my daily for long distance to work and back.

It is getting on in mileage so im looking to trade it soon and say goodbye to tuk tuk tuk ...

Blackwolfsa wrote: ↑Wed Nov 07, 2018 2:58 pm I am in Pretoria region.

Dont think they could diesel/air filter as they where replaced earlier in the year with normal service and the issue has persisted longer than that.

Well go visit trevor green and get a second opinion on the injectors out of spec and the noise.
083 309 5033.

I have had the car since day one (bought it new). It wasnt always like this, but the noise isnt really bothering me. For me its more a symptom. I more want the power sorted. The inaccurate fuel consumption is also to me a symptom as the true fuel consumption is not that bad.

I dont want to say it...but both these above mentioned cases sounds like injectors problems...

Seems like the only way to keep these engines going like it should is first, But it brand new, second chip the thing as soon as you get it.

A friend chipped his at 1000km, the car is now on 150,000km+ and has not flinched mechanically. His friend (a rep) bought one and di the same- he is now well over 180,000km and same story.

Personally I have one in my MK5 Jetta, the car always felt like something was just not right! Before installing the file, the car would do funny things to stress me out for nothing!!! After going stage one and removing the DPF she runs like a boss with exceptional fuel economy.

I though I would post some feedback.
I took the car to Trevor the other day, had removed the dpf. Car is now much better. Car is still not 100% but I am happy enough for now. The car said the dpf was clean, but also said it never did a regyn cycle.

The trip pc still measures the fuel consumption as too high, but its closer to actual. I have not driven a full tank so I cant compare the actual results. It might just be that the car is now lighter on fuel. But we did spot that the injector deviation is about 0.4 on all injectors when the engine is cold, but if warm, they go up to 1.4 and 1.7 on two of them.

Those two will eventually have to be replaced. You can actually fiddle the consumption numbers to be closer to actual in vcds if it bothers you. I don't ever care what the readout says. tank to tank is what counts.

Yip, its still better than the all 4 vw wanted to replace. He said they are still fine as long as they are between -2 and +2.

But the fuel consumption still bother me because on idle the trip pc is accurate. As soon as I start driving its starts to go inaccurate. This means the info its getting is inaccurate. Trevor looked at the intake manifold reading, he said its fine. But on every obd sensor I read it on, it was 88.6 constant, doesnt matter how much throttle there is. And as far as I have it, the air intake is used by the car to calculate the amount of fuel used. 88.6 is the idle setting, which means it will calculate correct on idle, but as soon as you drive, it wont as the sensor doesnt change.

Where does the intake manifold sit? I would like to have a personal look at it? And see if everything is fine there

There is very little to an intake manifold on a diesel. Sits behind the engine and other than looking at it I'm unsure what you will see.
I suspect the value you looked at was the atmospheric pressure reading and not the absolute manifold pressure reading.
There is a fiddle or fudge value that you can adjust to get more realistic OBC consumption readings. Every car differ and it does not use actual flow values. You can adjust that fiddle value to give you more accurate readings. It literally means nothing or is no indication of engine health that it difers from actual.

Just ignore the fuel consumption dislpay on the dash then.
Or change it to read something else if it seems to bother you that much. Like Stephan said, tank to tank consumption is what counts, not what the dash tells you.

I get what you guys are saying and I get that its just an indication.

If it was just inaccurate then yes, its the reading and I can adjust the fudge value to make it more accurate and what not. BUT the fact that the reading is accurate sometimes(idle) and inaccurate other times(partial load), means something is not right somewhere. Thats the problem, thats why I want to take a look there. From my experience as a computer engineer working with hardware sensors, its happens a lot that some sensor will get stuck(from dirt, build up of carbon etc). That reading will obviously influence the car's ecu when optimising fuel etc.