TitusM

And what are your stats now after new maf?

Where do you have this consumption? How much does it consume when driving out of the city. In my case I can say that I fixed lots of stuff that were wrong with the car. Unfortunately the consumption is not one of them:)). But I do have much better idle and no more leaks and the car is much more fun to drive. In your case - as far as i know polo is common rail. It is a non PD. Tehnically the next generation after lupo and audi 3l BUT the body is not the same. VW did not invest as much in bodywork anymore. My stats over all are 6.5-7 L/100km city and 4.4l/100Km outside/highway (usually city with the car almost empty and outside with the kids and wife so maybe around 120kg extra). I do own a vcds diagnose - without it is impossible to start somewhere(maybe vacuum leaks and other small checks). In your case I would start with the steps below: Usually with any car I start with (injectors and turbo are the last ones): 1)any visible leaks -- vacuum leaks -- and here I include N75 solenoid that moves the turbo vanes The easiest way to check this is with a hand vacuum pump (i bought a cheap one) with a meter on it. You pump and see the vacuum stays the same and also check each vacuum line - turbo, brakes, egr for leaks. To check the N75 solenoid I used a vacuum meter that I connected to the N75 output and i waw that the vacuum was not stable when idling. After fixing it I got less turbo lag. Lately i got a smoke machine from aliexpress. I fixed quite some issues with it(i did not know i had before it on the air intake side). The intake leaks fixed the lag quite a lot. 2)MAF -- in vcds engine -- see if when the engine runs the readings are moving and are in a reasonable area. This is usually one of the reasons vw's consume a lot. 3)lambda sensor if the engine has it. Euro 4+ usually have it. My 1.2 does not have lambda or nox sensor. You can check this if you look at the exhaust. If there is no sensor on it..than there is no nox/lambda sensor:)). Polo for sure has the sensor (maybe even 2 sensors one before and one after the catalytic converter) 4)check for any fuel leaks / even perforated filter hoses, fuel tank. Usually this type of leaks do not register on the car dash so you would catch those only if you calculate full/full. 5)check for stuck rear brakes but that usually is very easy because the rear rims get very hot if the case. 6)the last checks would be injectors and turbo. (also turbo leaks). In my case the injector deviation was fine until I changed the vacuum/tandem pump. After longer Idle there was "white" smoke. The high pressure pump was inserting oil into the fuel. After changing the tandem pump the car would idle better but when looking with vcds i noticed the injector deviation being greater (maybe the injectors were not as lubed with oil as before:)) ) What you have to take into considerations is that NONE of my cars consume "well". I owned: 1,2 tdi, 1.4 tdi, 1.6 tdi, 2.0 and hybrid gte. Each of them had their own particularities and i learned a lot about what causes consumption. I did not get as far as i got with the 1.2 tdi. This is the one I experienced a lot with and that I invested the most and learned a lot about diy diagnose. They tell me I drive quite aggressively so i assume at least 10 ,20% of consumption is my right foot.

Hi, Mine is euro3 so it does not have it. I checked. For now I believe the issue is one of the injectors (it was not visible until I changed the tandem/vacuum pump). The deviation is ~0.7 on one injector compared to the others. I read somewhere that on 1.2 the deviation is much smaller and 0.3 deviation might be an issue already. Since mine is 0.5 from 0 and 0.7 from the other injectors i declare it ...an issue:)). I will keep you posted. In September i will take the care to an expert shop for the gearbox and i will ask them to send the injectors and turbo for revision. I tested 2 other maf sensors - one pierburg and another miele and both of them give bad readings and even worse mileage. For now the original bosh maf seems to be the best (even on vcds the other ones give higher number when idle ~10% but when accelerating it drops very much compared to bosh).

yes:))) in the city.... And I am starting to believe that my driving style and the geography has a lot to do with it. When i get home i have to go uphill for 9KM. It is a demanding hill that asks a lot from the car (I drive usually full power). Outside the city the best I got so far is 4.4 l/100km.

Update: After fixing the air leaks the car runs better BUT 2 months into it and the consumption is again around 6.5l/100KM. I changed the tandem pump (high pressure/vacuum pump) since i suspected it for being a bit old. Replaced it with a pierburg one because i like the design better. The car idles much better now. It is not so rattly when idle. BUT...the consumption is the same. What I noticed is that in VCDS the injectors deviation is different now. One of the injectors is +0.5 and the others -0.2. I guess the problem might have been a bad injector all along but the old tandem pump hid this very well. What is next: I found a guy in my country that does all the gearbox -- bearings replaced, all pump o-rings replaced, hydraulic actuator upgrade. I will take the car there and ask them to take out the injectors and turbo and send it to testing. The turbo seems to have a little play so maybe there is some lack of power there too although it does not show on VCDS.

Sory I tought I answered your question. The total contact on the road is the same as for ecopias (because of the way the threads are built). Maybe ecopias have bigger contact surface (if we take into consideration what off-road drivers say). After a while i am back to same consumption of 6.5l/100. So tires have veeery little influence in my case. The tires i use now are falcon sincera ecorun. If you look at the threads you will understand what i mean -- much bigger distance between longitudinal threads.

6E0601025F They are...quite hard to find. Lupo 1.6 FSI had this model. It is 2cm wider than the classic 3l version but still very light. I did not compare rim to rim weight only complete wheels. About the tires I do have to make a comparison with the ecopias and those. I have a pair of rims with very old ecopias (scarry to drive them on wet surface). I believe that there is not a big difference (I would say 0.2-0.3 maximum on external) because I have eco version on the new tires and if I add up the contact area is the same as the ecopias only 10% weight added. The ride is far more comfortable with the 165 version...no doubt about it. Anyways...the 145 are nowhere to be found anymore. I wanted to buy a new set and no luck. Not even the winter continentals are not available anymore.

not even for the cleaning purposes? only water maybe?

Did you test water methanol injection in this engine? by any chance?

True. As I say power does not come only from air:)) you need to burn something in order to get extra horses. As lupo_3l said he used stock parts to go up to 125 and turbo was not yet at limit. It is good to hear from someone who tested stock parts to limits:). As for tire size...i am not sure that 145 makes a bit difference compared to 165 width. So far i like the ride better with the 165 and the contact surface is almost the same because of the way the tires are build. I bougth B/B markings and they seem to be much better than ecopias in terms of comfort and traction (but i still need to register the new tires and that will be a pain)

Awesome. So you are running manual gearbox? everyone says that 200nm is the limit and that is reached around 100hp if i remember correctly. It is nice to hear from someone who actually tested this things.

Thanks Manni. Yes I aim towards lower consumption but since I suspect turbo for wear I need to choose between upgrading to a more efficient turbo or repairing the old one. Maybe you are familiar with: https://forums.tdiclub.com/index.php?threads/1-2-tdi-tuning-info.390974/ I looked at what he did with his 1.2 lupo. He till has insane fuel consumption but he also done 100 other things to the car. I will not be able to go that drastic but i can implement part of modifications.

Are you sure? As far as I know Tuneko Ltd the one that tuned the 1.2 lupo a lot got 90hp from this engine with stock stuff therefore i believe the turbo is somewhat limited. The turbo on 1.4 tdi 90 is not the same with the one on 1.2 tdi. That's why I believe the 1.2 turbo is not as potent. I agree a bigger turbo has bigger lag but since only the pallets/wheels (going billet) are different I expect an improvement in efficiency for the same garret housing. I expect it to make better use of same flow since the billet wheels are lighter and have better airflow. In fact I expect lower lag because of better use of flow and decrease in spinning mass. Do you think I am looking at this wrong?

Fixed all the leaks from intake and added some superglue to the vacuum pump (there was no smoke coming out of it anymore). The turbo o-ring for the intake was a little hard to find but got one in the end. It is a different car now. It does not rattle so much in eco mode. It is a pain to drive 50km/hr (it rattles a bit because it shifts in 5th gear in eco mode). The consumption seems to have gone 1L down compared to the previous test I done in this topic last year. In eco mode mixed - mostly external I get now 3.9L/100km. In normal mode when i arrived at home after the steep hill the consumption was 4.4L/100km. I will be back with some city consumption after at least a month. (i do not drive the car that much ). STILL one weird thing: When pressuring the vacuum hoses with the smoke machine I noticed smoke coming from the engine air intake. I suspect that the tandem pump/vacuum pump is not good inside - it does not seal well between oil and vacuum maybe. The vacuum side should not communicate with the engine side/oil side at least not by my logic and knowledge so this might be another big issue. I ordered a new pump from pierburg (it seems to have a better design than the luk version i have on the car) . The new tandem pump price is around 200 euros today in 2024-05 on autodoc24 (the mobile app). This might also explain oil consumption - i taught that the valve seals might be old but now the tandem pump is also on the list. It would be nice if the pump solves the oil consumption too. The smoke test will be done again with the new pump. If the result is different this might be a good way to determine if the tandem pump is broken inside. I expect a big difference with the new tandem pump if not than the injectors and turbo will be next. The new turbo i've been looking at is this one: https://muchboost.com/product/1-2-tdi-hybrid-turbo-upgrade-audi-a2-volkswagen-lupo-seat-arosa-any-ayz/ . But for now i hope that the tandem pump will solve a lot.

Not sure if this topic has a conclusion or not. For me the bad consumption had several sources: 1)The T on the fuel filter (if you have the metal version -- the older ones) -It was cracked and air got into fuel system. 2)Air intake leaks -- on the oil stick pipe one o-ring was missing - after plugging this there was a big improvement. Also check the oil level sensor for missing or worn out orings. 3)air leak near turbo intake hose -- the o-ring was warn out and turbo was aspirating false air. 4)tandem pump might be defective inside - this is yet to be proven after I replace the current one with a new one. Find updates on my post. Usually the older version of tandem pumps had that issue with the hose plug getting loose BUT also with the seals between oil side and fuel side and vacuum side. You need to get a smoke machine for detecting leaks. You would not believe where the leaks are until you test for it. The car runs well with this leaks also and you cannot find anything specific on vag-com or computer diagnose.

I did not find the time to rebuild the engine. I am just very glad for finding the leaks posted above. I will come back with fuel consumption after this fixes. Next will be: 1)Injectors check and maybe repair if necessary. 2)Turbo check and clean - maybe upgrade the core and then a remap. 3)compression check although now after fixing those leaks i believe there will be a major improvement. 4)high pressure pump replacement with something newer that does not suffer from the vacuum hose issue. I am not sure I will do those this year. I still want to take out the engine and do a full check and rebuild but that requires also a garage that know I do not have. In the mean time since I did not write I had issues with the clutch hoses. The special clamp for the pressure hoses that go to the hydraulic actuator got broken and left me stranded for a while. I did purchase 3 clamps :)) for 20 euros/peace:)) I bought a wet aspirator and cleaned the seats. Another very good 100euros investment that will potentially save lots of money in the long run with the interior cleaning. The little bug did get a new set of wheels and summer tires. Unfortunately I could not find the original 145 ecopias anymore. Apparently 2023 was the last year you could buy those. I installed 165 version. The total weight is 1kg extra for each wheel compared to the winter continentals (10kg vs 11kg with new wider rims also) . I think the Lupo 1.4 fsi rims look much better than the 1.2 tsi vesion:). I got the rims from Poland.

1000 years later::)) update: I just bought from aliexpress a smoke machine for leak detection. I think this is a must have for this older cars. Issues i discovered: 1) huge leak near the oil sensor because of a missing o-ring. Solve it and the car already drives better. 2) small leak near the turbo intake. I have to remove the pipe before the turbo to see what is going on there but it leaks quite a lot 3) the classical leak from the vacuum pump hose (this one was very little but still there). I will try to find a good price for a new high pressure pump. My current consumption before fixing number issue 1) is city ~6.5l/100km and 4.3 external.

Reviving this topic after a long time:) I just purchased a full bose system from ebay -- wiring, amp, speakers etc. Thanks for all the hard work you've done long ago. It was very helpful to check all the wiring. I successfully installed it today but I have a few "errors": 1)It does not say bose at the beginning even after coding with vagcom - this is not so important but maybe useful for debugging. 2)The radio does not have front/rear anymore -- only left and right in settings. Is this normal (the blaupunkt version had fader -- front/back setting)? I own a2 1.2tdi 2001. I tried with the bose cable to eath connected and disconnected -- with coding and without coding and the result is the same. The unit sound good. There is tons of bass but i still have the old blaupunkt speakers and the subwoofer. This is another question -- is it worth the trouble in changing the speakers to bose ones?

Back after some more time:((( The consumption is still higher that other cars. The valve only solved part of the problem. I just bought a compression tester and injectors o-rings. After opening up the injectors I will decide if I will sent the injectors for rebuild.

@vfralex1977 Although 057127247A fits maybe the B version would be more suitable since the engines it is designed for have smaller power (90hp+). BUT the B version seems to have a different top. Maybe diameters are the same. let us know how "A" works for you.

8Z0501541 nicht mehr lieferbar. Was ist die beste Alternative? funktioniert 6Q0501541E?

The right side wish bone is not available at all in 2022..:((((. You can still find some on the left side. So from now on only refurbishing is available retro-mobile

@vfralex1977 Found the difference: So for the 1.2 the return line opens only when reaching 60 degrees:)))))) If no aftermarket part is found then the one with A should be fine. The only difference is that the engine will warm up later.... "On the 1.2l TDI engine, the fuel pre-heating valve does not open up the path to the fuel tank until the fuel temperature exceeds 60°C (1.4l TDI engine >30°C). As a result, the heat is concentrated on the engine and the engine reaches operating temperature more quickly"

Can you compare the 2 parts when they arrive? (FIRST let them site a while in the same temperature - they have a thermal plate inside) I tested mine blowing air with my mouth trough it and so I detected different air flow.

Well I fitted the one from vaico on a mann filter with no problems BUT make sure you install the valve out of the car. It is very hard to press it in the filter housing if you are under the car. This is the part I installed (and lots of other producers are available): https://www.autodoc.co.uk/vaico/2214688 I am pretty sure that the suggested part with 1J does not fit. (maybe some adaptation is needed but I do not see the reason if the one with A works well) I am not sure if changing to the plastic housing is a good idea. If something goes wrong with that housing you need to change it completely so you are back to the same job as for metal filter BUT it makes filter change 100 times easier AND I am pretty sure that using a "A" valve is the same as using a universal plastic housing. I usually change the fuel filter alt least every 2 years. (2 oil changes)