Low fuel economy in Logan Indian version 1.5 DCI 65 hp

[keanu_reeves]

We have a Logan DLE 1.5 DCi in the family. It used to return 20-27 kmpl on Diesel during its early ownership days. After 3rd service, the FE reduced and the vibrations of the engine increased suddenly. This was about 3 years back.

We tried all sorts of solutions to fix the vibrations and since then they have visibly reduced. But the FE remains abysmally low at about 9-10kmpl. Since the usage of the car has been city only, it barely runs ~700-800km / month. I usually drive the car have learnt to live with this low FE figure and was not even calculating how much FE the car was returning. But recently, I happened to check the FE (after the Diesel price hike) and realized that it returned a partly 9.5kmpl. = 10.5 ltrs for 100 km

There is no trouble with power delivery or acceleration. None of the parameters of ECU show any fault. The only *different* bit I could deduce was a whistling noise when the turbo spools up. But then this noise has been with us since day one when the car used to return 20-25+ kmpl. 5 to 4 ltrs per 100 km

1: Current odo reading is 47200km car is 2007 model
2: No starting problems. Starts in 1 crank always.
3: Smoke is colorless while idling, mild black smoke under high acceleration.
4: pick-up / acceleration. Normal as other Logans which return double FE.
5: Fuel Economy taken by Tankfull method
6: No error codes after resetting the ECU. Don't remember error codes prior to reseting. Reset was done in Sept. 2010. The car is not in Limp mode. I can rev all the way till 4-5k. Don't remember how much because I rarely take it over 3k.

 

[henry66]

keanu, welcome here on the forum, and tks for the long report. i hope
somebody else will chip in here too, but for now i will try to answer a bit.

- vibrations: reducing them is one thing, but did they actually find out what
caused them?

- FE (fuel economy - please stick to the liters/100km system, so people here
understand what you are talking about) at 10.5l/100km is really bad.
even in the city (unless you are in delhi or mumbay and do a constant
start-stop-start-stop with the aircon going too). so where do you live, where
do you drive?

have you tried to measure an overland trip? recently? you should come down
to some 6l/100km - some people even mange much less, under 5 is possible.

- the whisteling noise: totally normal, it would be the turbocharger. it whistles
on ALL turbo charged cars, some more, some less - many people actually like it.

- Fuel Economy taken by Tankfull method

that IS a problem. fill up the car at a station slighlty slanting forward down
and to the left, and your tank will take 65++ (!) liters easily. YES, this is true,
even in india! there are pics here on the forum with people taking 70l max - the
LOGAN and the MCV have the very same tank.

go to another station, slanting upwards, and a bit to the right, and your tank
will only take 55 liters - the last few always VERY VERY slowly, but take them.

so if you do measure with the 'Tank Full' method, use always the same pump.
if it switches off automatically, you will under normal conditions still be able to
add some 10-15 liters, easily. BUT SLOWLY. dont ever try this when you
have a line of cars waiting behind you - they will stone you.

a known dacia issue, but actually an advantage if you have stations with great
difference in price. if you can save 1000 INR when filling up 60+ liters at one
station rather than another, here in europe maybe even in another country, good
for you, no?

DONT do that when it is hot, and you do not imediately drive at least another
30-50km.

so, lets see what other have to say.

greetings - henry

 

[keanu_reeves]

so, lets see what other have to say.

greetings - henry

Thanks for your respnse henry
I think these will add some more info

a: They cleaned the EGR Valve and the vibrations reduced (I really do not know what they mean)
b: I drive in Nasik Near Mumbai there is not much trafic in Nasik
c: I fill that way only there are Fuel Stations at the highway which stay quite deserted and give me at least 50+ liters (I refill when i see the last bar and the fuel is INR 1.5 less than the city only 10km drive)
d: The fuel economy of 10.5 ltrs /100 km is constant on highway and city. I drive 600 -700 km a month in the city with a 400 - 500 Km highway streach atleast once in 2 months city speed is 40-60 KMPH and highway 80-110 KMPH aircon is always on (Aircon used to be on previously also when i used to get a FE of 4-5l/100 km )
I even used to idle the car with the aircon on for waiting for some one for 20-30 mins still good Fuel Economy was there. now i switch off the car as soon as I stop.

one more thing i would like to add the ECU was reset by disconnecting it from the car for 30 mins

 

[keanu_reeves]

Hey there, I now remembered a very important detail.

Back in September 2008, this car was flooded till the height of the tyre, the water level was so low that seat base was not submerged completely. Also, ECU was not submerged in the flood water. We did not start the car after this happened and it was then towed to the Service center by breakdown assistance service. They kept the car for 1 week, cleaned it thoroughly in and out (as per what they say) and returned it with the car performing (in acceleration) as well as the car prior to flooding. But that was also when we first started noticing reduced fuel economy. Prior to floods it used to be 3.6 to 5l/100km. Immediately after the floods, it used to be 6-7 l/100km. This aspect was checked at the Service center but the service center made excuses and did not fix it at the time. Since we were pretty much okay (but not happy) with this particular figure after followups for over 1 year, we got fed up and stopped complaining.

Could this aforementioned event have led to some dirt being stuck somewhere in the car which has been fouling with the Fuel economy all these years?

 

[henry66]

keanu, tks for those updates. wish someone else would also put in his few pennys worth, but i will try. we have a fleet of 80 LOGANs, which i supervise. few diesels only, but the basic issue is the same.

- you measuring method is just no precise enough. one bar on the gauge can mean still 10+ liters in the tank, or even only 4. thats about the upper/lower limit when one single bar shows.

- your initial 3.6-5 l/100km points this also out, there is no LOGAN in the world that manages 3.6, sorry. 5, yes, but 3.6, no.

- that said, it still does not account for you extreme figures

- yes, i know Nasik, by far not the traffic that would account for that excessive consumption

>> September 2008, this car was flooded till the height of the tyre

thats more like it. it could have clogged up the entire exaust system, inkl the catalysator, and whatever. see if a street-side garage can replace the entire exaust system with a cheap locally made one (usually as good as 'empty' anyhow), and see if this immediately changes FE. the car might be a bit loud for a week or two, but with fairly little money you can find out what is wrong. you can then always opt back for a 'proper' one.

>> we got fed up and stopped complaining

would not settle for this at all. have you talked to a technician at DACIA directly? whatever his excuses might be, he would HAVE to tell you that and average of 10.5l/100km (converted) is literally impossible.

dont quite understand how you can have gone with this for years! you spend a fortune on extra fuel alone.

greets - henry

 

[Max I. Mumm]

hi friends,

I only understand railway-station

 

[keanu_reeves]

Dear henry
Thanks for your input

>> you measuring method is just no precise enough. one bar on the gauge can mean still 10+ liters in the tank, or even only 4. thats about the upper/lower limit when one single bar shows.

One bar may mean any thing but I take the fuel economy by the number of liters consumed in the tank. Do not make the tank empty before refueling. So I think it is quite accurate and as per you told me.


>> your initial 3.6-5 l/100km points this also out, there is no LOGAN in the world that manages 3.6, sorry. 5, yes, but 3.6, no.

3.6 came to me when the car was in run in and on the highway speed was always between 60-100 kmph


>> thats more like it. it could have clogged up the entire exaust system, inkl the catalysator, and whatever. see if a street-side garage can replace the entire exaust system with a cheap locally made one (usually as good as 'empty' anyhow), and see if this immediately changes FE. the car might be a bit loud for a week or two, but with fairly little money you can find out what is wrong. you can then always opt back for a 'proper' one.

Will try that too over the weekend but don't think any roadside mechanic will touch this car since this being one of the Premium cars in India (80% cars sold in India by volume are cheaper than the Logan).

>> would not settle for this at all. have you talked to a technician at DACIA directly? whatever his excuses might be, he would HAVE to tell you that and average of 10.5l/100km (converted) is literally impossible.

as you may know Mahindra Renault assemble Logan In Nasik itself. The problem here being that Mahindra Renault shut shop in India last year and now all older Mahindra Renault Logans are serviced by 'Mahindra & Mahindra' who have very limited knowledge about Logan. I have contacted many people there from the M&M/M-R factory over the years but they too could not detect the problem (There is no one from Dacia or Renault working in the Plant as of now. Mahindra people assembling SKD car have almost 0 knowledge of the car.). I tried visiting some local Logan and other cars related forums but as the problem is so unique no one could reply.

Now as there is a substantial decrease in the mileage and Increase in fuel prices I started to visit forums in the European Countries so I could get some help.

 

[henry66]

>> So I think it is quite accurate and as per you told me

no it is not, as you yourself proved. 3.6 is out of range, totally, any condition or driving habit. you have to find a way for more accurate consumption measurement if you want to base your findings on it.

anyhow, the max of 10.5 (and it would not matter if 11.7 or 9.6 or thereabouts) if fully out of range.

>> but don't think any roadside mechanic will touch this car

any roadside mechanic in india (there are those that only do exausts) will do whatever you tell him and what you pay for. if you tell him what you are after, he can do this without any damage to the original system, and without it being even able to be detected. tell him what you suspect, and he will know how to put in something momentarily, but solidly.

i am aware of the situation of DACIA and M&M, but your problem is not DACIA specific, nor RENAULT: any decent mechanic, any good garage, will pinpoint the issue immediately. you do NOT need any knowledge for this car specifically.

>> the problem is so unique no one could reply

no it is not. a clogged up exhaust or cat is quite common, since the clogging is not alway solid, but fine dust, it can even be different going uphill or downhill, in the extreme.

>> I started to visit forums in the European Countries so I could get some help

help you will get, but only if you also follow those suggestions trying to corner the culprit. and the exaust is the most likely one.

greets - henry

 

[keanu_reeves]

Hi Henry
My car always gave unbelievable Fuel Economies. first it was 3.6% and now it is 10.5%

we cleaned the EGR Valve again checked the ECU. the Service Center is ready to do some other tests also to check the fuel efficiency.

I have talked about the exhaust to some people but It is a really long weekend Holiday till Wednesday. will get back to you after after I get any other important info.

 

[henry66]

>> ... unbelievable ...

that, kaenu, is the point.

greets - henry

 

[keanu_reeves]

@Henry, We reconfirmed with the SVC and rechecked the EGR valve manually. It was always clean. EGR valve on my car gets cleaned by removing everything practically every 4k km. Free Flow pipe I have been advised against by the M&M engineer (and roadside garages stayed closed over the weekend due to festival and on Tuesday due to National Holiday in India) so I have not done it till now.

Also we did a proper mileage run yesterday in presence of 2 Service center chaps and 1 engineer from M&M.

Filled up the tank right upto the brim at the same filling station with the car parked in the exact same spot and we did this exercise thrice.

4 people in the car, 100% Highway drive with speeds varying between 100-120 kmph in top gear. 47km in 2.3 liters OR 4.9l/100km.

2 people in the car, 100% city drive with speeds varying between 25-50 in 3rd-4th gear, 50 seconds of idling overall. 15km in 1.52 liters or 10.1l/100km.

Before doing this particular exercise, I had used the car for a week after filling to the brim. Totally did 408km with 20km on highway and rest 388 km inside city conditions. Before starting the aforementioned mileage run, the tank was topped up with 37.7 liters of Diesel. 408 km in 37.7l comes to 9.24l/100km.

As of now, I have been assured that they will figure out the problem which is causing such a massive difference in FE. Lets see how this progresses.

 

[henry66]

there is simply no way you can do accurate measurements with 47 or 15km driven, a simple airbubble when filling will throw you off by 2-3/l/100km.

>> Before starting the aforementioned mileage run, the tank was topped
>> up with 37.7 liters of Diesel. 408 km in 37.7l comes to 9.24l/100km

is this a typo? it does not matter how much was filled up before the run, but during/between the run.

>> Free Flow pipe I have been advised against by the M&M engineer

naturally he would. is it the same guy who cannot trace your excessive FE? the pipe will only be there for testing and limiting the possibilities. its not supposed to be there for the rest of your life.

>> I have been assured that they will figure out the problem
>> which is causing such a massive difference in FE

well, being 'assured' after something like one year++ is quite something.

>> Lets see how this progresses

whatever it turns out ot be, pls let us know.

greets - henry

 

[keanu_reeves]

there is simply no way you can do accurate measurements with 47 or 15km driven, a simple airbubble when filling will throw you off by 2-3/l/100km.

>> Before starting the aforementioned mileage run, the tank was topped
>> up with 37.7 liters of Diesel. 408 km in 37.7l comes to 9.24l/100km

is this a typo? it does not matter how much was filled up before the run, but during/between the run.

I knew you would say that it is not possible to calculate FE with so low running. BUT, I had done a tank full upto the brim 408km *before* doing these latest controlled FE runs. So Tankfull to Tankfull Diesel used was 37.7l for 408km. i.e. 9.24% for 95% city + 5% highway usage. I hope 1/2 tank+ is enough for getting an accurate reading. Also, this result is quite close to the results we got on the controlled FE run.

>> Free Flow pipe I have been advised against by the M&M engineer

naturally he would. is it the same guy who cannot trace your excessive FE? the pipe will only be there for testing and limiting the possibilities. its not supposed to be there for the rest of your life.

greets - henry

No, not the same guy. This engineer stays in my building and assures me that he will take the vehicle back to factory (not service center) and troubleshoot the problem at company cost using company resources. This will be happening by today evening/tomorrow. Thats why he doesn't want me spend unnecessarily on stuff that I will not need for long term. If I hit a dead end on that front in the next couple of days, I am going back to your suggestion and getting the free flow pipe installed for sure.

I am also in touch with a member called "Texas Ranger" on this forum (over PM) who has helped me confirm that the ECU of my car has not been changed and still is the one which came from factory.

Another member dani030669 from Logan club Romania forum has said the following after I posted the exact same FE figures data there. (Posting here since this is the most active thread of all.)

have you checked air pressure to intake manifold? it must be around 0.8 bar for dci 48kW,
have you tried to keep engine around 2000rpm? (in my experience from 50kph to 65kph fuel consumption is lower in 3rd gear than in 4th gear because engine runs more efficient from 2000 to 2500 rpm than under slower revs)
also FE indicated on AVG speed under 20Kph on my car exceeds 7l/100km, 6.5l/100km for 22 kph, 6l/100k for AVG speed 28kph, and is equal to factory's declared urban consumption (5.3l/100km) at AVG speed of 35 kph. (all vallues was recorded with AC on)
idle consumption is 0.4-0.6 l/h depending on AC status

I assume we can check this by accessing historic data from ECU? Or do we need OBDII connector to check it while the car is running?

 

[henry66]

>> troubleshoot the problem at company cost using company resources.
>> This will be happening by today evening/tomorrow

yes, then it makes sense to not even try anything major in-between.

TEXAS here on the forum is a real expert for any technical matters. his guidance should really be valuable.

the figures of DANI should be correct and within range, nevertheless they are VERY far away for your figures.

keep us posted, pls.

greets - henry

 

[keanu_reeves]

Update: Yesterday, I got myself a Bluetooth OBD2 connector and used both Android Torque app and Laptop to connect it.

It doesn't work with Logan. But it works very well with my Honda Civic. So connector is not faulty. When I connect it with Logan, I get the error "ECU not communicating. Make sure your vehicle ignition is on." So, we have yet again hit a dead end.

So we went back to Service center with drooping shoulders to ask them what can be done. Checked the intake manifold pressure that Dani from the other forum mentioned. There we found out that the OBD2 doesn't work on Logan, but it works on the mechanically and visually identical Rebadged Logan, also known as Mahindra Verito. Apparently they have changed the ECU on Verito from Delphi to Bosch.

It was found to be around 908 mbar OR 0.9 bar. Then we (I and my brother) *kidnapped* the service head of the service center and we did a leak-off test using their laptop (to test if there is any diesel leakage).

This is the result we got. The only bit he couldn't understand was this bit I am pointing at.

Why is there a reading on reset number 2 injector no 1 and injector no 2 and the reading is same on the injector 3 and 4. What does this mean? I have mailed this to Texas Ranger.

P.S.: I can get the entire test result we got from logging all log-able parameters of the car for a period of 335 seconds if you guys need it for further scrutiny. You need to have the software that Renault uses it to read it (since it was a binary .dat file).