Indigo DICOR - Idling issues??

cnaganathan · 10th August 2009, 10:26

After the third service, I noticed a drop in the FE of my Indigo Dicor from 12.5kmpl to 11.7kmpl

Yesterday I noticed a strange thing - When the vehicle is stand still and clutch pedal pressed down, rpm is close to 1000 mark. This is the case even if the gear is in neutral. However, if I take my foot off clutch pedal with the gear in neutral, rpm drops down closer to 800 mark.

Can this be a reason for the increased Fuel consumption as most of my driving is in peak hour traffic and I have to operate the clutch frequently.

cnaganathan · 10th August 2009, 17:43

Here are the pictures I took. The first one shows rpm with clutch pedal pressed down while the second one is when the clutch is released. Both were shot with gear in neutral.

greenhorn · 10th August 2009, 18:03

was the AC on ?

could this be due to the AC/electricals load ?

cnaganathan · 10th August 2009, 18:41

Quote:

Originally Posted by greenhorn

was the AC on ?

could this be due to the AC/electricals load ?

A/C, electricals both were on fully in both cases. I tried both cases (clutch pedal pressed and released) with electricals and A/C switched off too - still the rpm when clutch pedal is pressed was higher than when it is released.

athalaga · 11th August 2009, 10:56

Quote:

Originally Posted by greenhorn

was the AC on ?

could this be due to the AC/electricals load ?

Exactly my question too greenhorn.

the idle speed must not change if you are in neutral and the clutch is depressed, (the idle speed does increase when the AC is turned on).
Now that you say its not due to the AC I have one more query.
Is this the case everytime you try it or is it just your tacho variability.

anky · 11th August 2009, 15:10

Hi I have an lx dicor ( indigo) 2007 model I to notice the difference when cluth is pressed , I too have noticed the drop in FE to 12.5 and noticed the engine drinks coolant more faster than it should and the engine getting noisier than what it was 1 yr back.Power windows sometimes get stuck ... but on the whole the dicor engine is far better than the tdi and has great pickup and torque...Not trying to make any point just thought I share my expirence too...

cnaganathan · 11th August 2009, 17:35

Quote:

Originally Posted by athalaga

Is this the case everytime you try it or is it just your tacho variability.

This is not tacho variability. I have tried at different times - when the engine is just warm and has run a few minutes, when the engine is hot after a short run and the engine is hot after a long run. It is always like this. And as I mentioned earlier, this is the case only after 3rd service was done.

im_srini · 11th August 2009, 17:52

Assuming everything else being the same, the only difference would be that in one case you're spinning the gears within the gearbox & in the other, you're not. With the clutch fully depressed the engine's isolated from the transmission, so the only load on it would be the A/C & alternator.

In neutral, with your foot off the clutch, the engine's still spinning the gears inside the gearbox. So the extra drag could be reducing the idling RPM a bit. Maybe you could check if they forgot to fill the gearbox with oil (been known to happen !) in case it was drained for replacement. Before your service, what were the idle RPM like, was it 800 or 1000 ?

In any case, from the pics, the difference appears to be very small...

cnaganathan · 18th September 2009, 10:45

Well I noticed a new wierd behavior two days back and verified it again today. Here is how it goes:
- Accelerate car to 60 kmph (4th gear) and then shift to Neutral
- Keep feet off all pedals and let car glide along.
- idle rpm stays close to 1000 (the way it is when idling with clutch pedal pressed)
- As speed drops to below 45kmph, rpm starts rising and when peaks at close to 1250 when speed drops to 35kmph!!
- Thereafter tacho stays close to 1000rpm till the vehicle come to a complete halt - irrespective of whether clutch is pressed or not

Questions:

1. Is this normal behavior? Has someone else observed this in their car too?
2. If this is abnormal what could be the issue - clutch, an ECU sensor or the ECU itself?

Some points to note:
1. Some Clutch components (IIRC - Release bearing and Pressure plate) were replaced FOC under warranty at 8k kms when I complained of a Hard clutch.
2. I do not remember such behavior prior to 3rd service.
3. Switched over to Mobil 1 Synthetic oil during 3rd service
4. Car has run 21k kms in 13 months and is handled by me mostly with an occasional drive by my driver.
5. Most of the run has been in city - peak hour.

DerAlte · 18th September 2009, 11:53

@cnaganathan, you should be a Test Engineer for the auto manufacturers, since you seem to think of Test Cases which they might never have thought about! :

The ECU controlling the injection quantity at any point of time has at least about 20 different conditions to reckon with to calculate the injection quantity. Ironically, it does not know which gear, if at all, has been engaged - though it does know the clutch has been depressed, but not how much. There are conditions where the ECU has to predictively increase the injection to help the driver, like Uphill Start Assist in higher end vehicles. Such behavior is non-intuitive for most users, but normally has a technical basis. Maybe you could measure the RPM when trying to start the car uphill WITHOUT pressing the acc pedal (only on half-clutch)?

10th August 2009, 10:26	#1
cnaganathan BHPian Join Date: Jul 2008 Location: Chennai Posts: 281 Thanked: 48 Times View My Garage	Indigo DICOR - Idling issues?? After the third service, I noticed a drop in the FE of my Indigo Dicor from 12.5kmpl to 11.7kmpl Yesterday I noticed a strange thing - When the vehicle is stand still and clutch pedal pressed down, rpm is close to 1000 mark. This is the case even if the gear is in neutral. However, if I take my foot off clutch pedal with the gear in neutral, rpm drops down closer to 800 mark. Can this be a reason for the increased Fuel consumption as most of my driving is in peak hour traffic and I have to operate the clutch frequently.
	() Thanks

10th August 2009, 17:43	#2
cnaganathan BHPian Join Date: Jul 2008 Location: Chennai Posts: 281 Thanked: 48 Times View My Garage	Pix attached Here are the pictures I took. The first one shows rpm with clutch pedal pressed down while the second one is when the clutch is released. Both were shot with gear in neutral. Attached Thumbnails
	() Thanks

10th August 2009, 18:03	#3
greenhorn Senior - BHPian Join Date: Apr 2007 Location: KL-01 Posts: 7,744 Thanked: 4,387 Times View My Garage	was the AC on ? could this be due to the AC/electricals load ?
	() Thanks

11th August 2009, 15:10	#6
anky BHPian Join Date: Apr 2006 Location: Mumbai Posts: 402 Thanked: 115 Times	Dicor same issues + more Hi I have an lx dicor ( indigo) 2007 model I to notice the difference when cluth is pressed , I too have noticed the drop in FE to 12.5 and noticed the engine drinks coolant more faster than it should and the engine getting noisier than what it was 1 yr back.Power windows sometimes get stuck ... but on the whole the dicor engine is far better than the tdi and has great pickup and torque...Not trying to make any point just thought I share my expirence too...
	() Thanks

11th August 2009, 17:52	#8
im_srini BHPian Join Date: Sep 2006 Location: Portland Posts: 1,010 Thanked: 489 Times View My Garage	Assuming everything else being the same, the only difference would be that in one case you're spinning the gears within the gearbox & in the other, you're not. With the clutch fully depressed the engine's isolated from the transmission, so the only load on it would be the A/C & alternator. In neutral, with your foot off the clutch, the engine's still spinning the gears inside the gearbox. So the extra drag could be reducing the idling RPM a bit. Maybe you could check if they forgot to fill the gearbox with oil (been known to happen !) in case it was drained for replacement. Before your service, what were the idle RPM like, was it 800 or 1000 ? In any case, from the pics, the difference appears to be very small... Last edited by im_srini : 11th August 2009 at 17:56.
	() Thanks

18th September 2009, 10:45	#9
cnaganathan BHPian Join Date: Jul 2008 Location: Chennai Posts: 281 Thanked: 48 Times View My Garage	Wierd behavior - noticed a new one Well I noticed a new wierd behavior two days back and verified it again today. Here is how it goes: - Accelerate car to 60 kmph (4th gear) and then shift to Neutral - Keep feet off all pedals and let car glide along. - idle rpm stays close to 1000 (the way it is when idling with clutch pedal pressed) - As speed drops to below 45kmph, rpm starts rising and when peaks at close to 1250 when speed drops to 35kmph!! - Thereafter tacho stays close to 1000rpm till the vehicle come to a complete halt - irrespective of whether clutch is pressed or not Questions: 1. Is this normal behavior? Has someone else observed this in their car too? 2. If this is abnormal what could be the issue - clutch, an ECU sensor or the ECU itself? Some points to note: 1. Some Clutch components (IIRC - Release bearing and Pressure plate) were replaced FOC under warranty at 8k kms when I complained of a Hard clutch. 2. I do not remember such behavior prior to 3rd service. 3. Switched over to Mobil 1 Synthetic oil during 3rd service 4. Car has run 21k kms in 13 months and is handled by me mostly with an occasional drive by my driver. 5. Most of the run has been in city - peak hour.
	() Thanks

18th September 2009, 11:53	#10
DerAlte Senior - BHPian Join Date: Mar 2007 Location: Bangalore Posts: 8,069 Thanked: 2,919 Times	@cnaganathan, you should be a Test Engineer for the auto manufacturers, since you seem to think of Test Cases which they might never have thought about! : The ECU controlling the injection quantity at any point of time has at least about 20 different conditions to reckon with to calculate the injection quantity. Ironically, it does not know which gear, if at all, has been engaged - though it does know the clutch has been depressed, but not how much. There are conditions where the ECU has to predictively increase the injection to help the driver, like Uphill Start Assist in higher end vehicles. Such behavior is non-intuitive for most users, but normally has a technical basis. Maybe you could measure the RPM when trying to start the car uphill WITHOUT pressing the acc pedal (only on half-clutch)?
	() Thanks