i10 1.2: RPM goes up when clutch is pressed. Normal?

Su-47 · 25th August 2008, 11:21

Hi All,

We have this i10 Kappa (1.2), which is less than a month old and I've noticed something strange with it:

At slow speeds, when I press the clutch (and of-course release the accelerator), the RPM shoots up for about 2 seconds and then settles down. This is observable when the car is being parked (as road noise is practically absent in the basement car park). Is this normal?

I talked to Trident Hyundai guys and they claimed that this happens with all the cars, especially when they are being reversed. I am not inclined to trust that, hence this question.

Thanks,
Su-47

for_cars1 · 25th August 2008, 11:39

Quote:

Originally Posted by Su-47

Hi All,

We have this i10 Kappa (1.2), which is less than a month old and I've noticed something strange with it:

At slow speeds, when I press the clutch (and of-course release the accelerator), the RPM shoots up for about 2 seconds and then settles down.
Su-47

Oh, so it happens in the i10 Kappa too ? I've been experiencing the same problem/behaviour/phenomenon on the Santro Xing (pre-eRLX) for nearly 3 years now.
Seems to some (strange) ECU programming on Hyundai cars which shoots up the RPM on pressing the clutch.
I've not experienced this on any other car brand though

Can anyone else confirm this behaviour

jav · 25th August 2008, 11:48

test drive another i10 and see if the rpm goes up

BaCkSeAtDrIVeR · 25th August 2008, 11:50

Nothing like this in WagonR

Su-47 · 25th August 2008, 12:08

Quote:

Originally Posted by jav

test drive another i10 and see if the rpm goes up

Thought of doing that, but, when I went to the workshop, the testdrive car had gone out. Will do some other time..

Quote:

Originally Posted by for_cars1

Oh, so it happens in the i10 Kappa too ? I've been experiencing the same problem/behaviour/phenomenon on the Santro Xing (pre-eRLX) for nearly 3 years now.

I will try it on another i10 again, when I get the time. Will keep you posted...

howler · 25th August 2008, 12:52

This is bound to happen under the circumstances you cited. Very simply when the clutch is engaged the engine in under load and the rpm is bound to be lower than when disengaged, the moment you disengage the clutch the ecu will take some time to alter the amount of charge going in to the cylinders and hence to spike. The drop back to normal levels is an indication that the correct charge at idle is being allowed into the cylinders, all happens in a fraction an is nothing to worry about.

Su-47 · 25th August 2008, 14:26

Howler,

If it happens in a fraction of a sec, I shouldn't be able to notice it. I think it takes about 1-2 secs to happen. Is that also normal?

Cheers,
Su-47

howler · 25th August 2008, 14:35

Quote:

Originally Posted by Su-47

Howler,

If it happens in a fraction of a sec, I shouldn't be able to notice it. I think it takes about 1-2 secs to happen. Is that also normal?

Cheers,
Su-47

oh ok, not too sure about it now, i guess the best bet would be to drive other kappas, it could be characteristic to the car, but it sounds like a lag in the response time of the ecu,i maybe wrong too, experts;your comments please?

amitpunjani · 25th August 2008, 14:50

Hi there

I have exactly the same problem with my brand new Santro, trust me i have banged every door of Hyundai Service Centres but till date nobody able to tackle the problem. This fluctation of RPM occurs mostly in B2B traffic. Just trying to live with me.

From the service advisors i have got all sorts of explanation, but one answer was a bit reasonable. He said that the ECU is of 8 BIT ( low capacity)

Amit

nma83 · 25th August 2008, 15:18

I have a Getz 1.1 and exactly the same things happens to me too. Looks like a characteristic of Hyundai ECUs!

mtnrajdeep · 25th August 2008, 16:08

I have an SX4 and the same happens there!! When asked about it, one of the service guys mentioned that it would reduce after running about 10,000 km! The rpm shoots up by about 500 rpm and then slowly settles down. Have decided to wait and watch!

amitpunjani · 25th August 2008, 16:09

Quote:

Originally Posted by nma83

I have a Getz 1.1 and exactly the same things happens to me too. Looks like a characteristic of Hyundai ECUs!

Hi

This is because both the cars share the same engine. I still fail to understand why the service advisors don't have a clue about this problem is Hyundai Service stations.

Amit

Revvhead · 25th August 2008, 16:11

I second what howler says.

This is a basic phenomenon for all engines.
There is a certain load for the engine at say 1000 rpm. when you disengage the clutch, you have removed all load for the engine, and with the reduced load the throttle ( fuel rack) has to reduce as well to maintain that 1000 rpm. The time taken to effect that change will depend on the programming of the throttle control software, amongst other factors, and in that period the rpm will increase before stabilising at its original rpm.

Guna · 25th August 2008, 16:18

Yes, I think this is very normal, if it is only marginal(200-300 rpm) for a second or so.

Firebird · 25th August 2008, 17:23

I have noticed this in UVA, but this happens only at the start of the day or engine is cold.

The typical cycle is

At cold - Start - RPM - 1100
Engage 1st Gear - Rpm increases and drops to 1000
Press clutch and engage 2nd - for a moment the RPM shoots up and settles down to 1000.

Suddenly if I have to stop and I press clutch and disengage, on pressing clutch, RPM shoots up to 1300 or so and settles down now to 1000.

Eventually after a 0.5 KM or so all becomes normal and On depressing clutch The RPM settles at 800, which is normal operating RPM.

I think, the theory might be (I am no tech guy in this, just trying to apply logic) the engine runs rich at start and we try to reduce the RPM by not accelerating or by using the rich mixture to move ahead. The moment we disengage (press Clutch), the engine goes back to rich mode at idle (which is seen at start). Thus RPM shoots up.

The engine later runs lean gradually and all works at normal at 800 rpm.

The strange thing is I have never noticed this behaviorin MY Palio 1.6.

25th August 2008, 11:21	#1
Su-47 BHPian Join Date: Aug 2006 Location: Bangalore Posts: 692 Thanked: 337 Times	i10 1.2: RPM goes up when clutch is pressed. Normal? Hi All, We have this i10 Kappa (1.2), which is less than a month old and I've noticed something strange with it: At slow speeds, when I press the clutch (and of-course release the accelerator), the RPM shoots up for about 2 seconds and then settles down. This is observable when the car is being parked (as road noise is practically absent in the basement car park). Is this normal? I talked to Trident Hyundai guys and they claimed that this happens with all the cars, especially when they are being reversed. I am not inclined to trust that, hence this question. Thanks, Su-47
	() Thanks

25th August 2008, 11:48	#3
jav BHPian Join Date: Apr 2007 Location: Bangalore Posts: 224 Thanked: 66 Times	test drive another i10 and see if the rpm goes up Last edited by jav : 25th August 2008 at 12:00.
	() Thanks

25th August 2008, 11:50	#4
BaCkSeAtDrIVeR BANNED Join Date: Jun 2007 Location: Kochi Posts: 2,522 Thanked: 752 Times	Nothing like this in WagonR
	() Thanks

25th August 2008, 12:52	#6
howler BHPian Join Date: Aug 2008 Location: coorg/bangalore Posts: 447 Thanked: 570 Times	This is bound to happen under the circumstances you cited. Very simply when the clutch is engaged the engine in under load and the rpm is bound to be lower than when disengaged, the moment you disengage the clutch the ecu will take some time to alter the amount of charge going in to the cylinders and hence to spike. The drop back to normal levels is an indication that the correct charge at idle is being allowed into the cylinders, all happens in a fraction an is nothing to worry about.
	() Thanks

25th August 2008, 14:26	#7
Su-47 BHPian Join Date: Aug 2006 Location: Bangalore Posts: 692 Thanked: 337 Times	Howler, If it happens in a fraction of a sec, I shouldn't be able to notice it. I think it takes about 1-2 secs to happen. Is that also normal? Cheers, Su-47
	() Thanks

25th August 2008, 14:50	#9
amitpunjani BHPian Join Date: Jul 2007 Location: Delhi Posts: 451 Thanked: 109 Times	Hi there I have exactly the same problem with my brand new Santro, trust me i have banged every door of Hyundai Service Centres but till date nobody able to tackle the problem. This fluctation of RPM occurs mostly in B2B traffic. Just trying to live with me. From the service advisors i have got all sorts of explanation, but one answer was a bit reasonable. He said that the ECU is of 8 BIT ( low capacity) Amit
	() Thanks

25th August 2008, 15:18	#10
nma83 BHPian Join Date: May 2007 Location: Bangalore Posts: 356 Thanked: 261 Times View My Garage	Same in the Getz 1.1 I have a Getz 1.1 and exactly the same things happens to me too. Looks like a characteristic of Hyundai ECUs!
	() Thanks

25th August 2008, 16:08	#11
mtnrajdeep BHPian Join Date: Feb 2006 Location: Bangalore Posts: 904 Thanked: 338 Times View My Garage	I have an SX4 and the same happens there!! When asked about it, one of the service guys mentioned that it would reduce after running about 10,000 km! The rpm shoots up by about 500 rpm and then slowly settles down. Have decided to wait and watch!
	() Thanks

25th August 2008, 16:11	#13
Revvhead BHPian Join Date: Apr 2005 Location: Bombay Posts: 450 Thanked: 20 Times View My Garage	I second what howler says. This is a basic phenomenon for all engines. There is a certain load for the engine at say 1000 rpm. when you disengage the clutch, you have removed all load for the engine, and with the reduced load the throttle ( fuel rack) has to reduce as well to maintain that 1000 rpm. The time taken to effect that change will depend on the programming of the throttle control software, amongst other factors, and in that period the rpm will increase before stabilising at its original rpm.
	() Thanks

25th August 2008, 16:18	#14
Guna Senior - BHPian Join Date: Nov 2007 Location: Bangalore Posts: 4,011 Thanked: 4,202 Times	Yes, I think this is very normal, if it is only marginal(200-300 rpm) for a second or so.
	() Thanks

25th August 2008, 17:23	#15
Firebird BHPian Join Date: Jul 2005 Location: Mumbai / EC1M 3NH Posts: 470 Thanked: 65 Times View My Garage	I have seen this at cold start I have noticed this in UVA, but this happens only at the start of the day or engine is cold. The typical cycle is At cold - Start - RPM - 1100 Engage 1st Gear - Rpm increases and drops to 1000 Press clutch and engage 2nd - for a moment the RPM shoots up and settles down to 1000. Suddenly if I have to stop and I press clutch and disengage, on pressing clutch, RPM shoots up to 1300 or so and settles down now to 1000. Eventually after a 0.5 KM or so all becomes normal and On depressing clutch The RPM settles at 800, which is normal operating RPM. I think, the theory might be (I am no tech guy in this, just trying to apply logic) the engine runs rich at start and we try to reduce the RPM by not accelerating or by using the rich mixture to move ahead. The moment we disengage (press Clutch), the engine goes back to rich mode at idle (which is seen at start). Thus RPM shoots up. The engine later runs lean gradually and all works at normal at 800 rpm. The strange thing is I have never noticed this behaviorin MY Palio 1.6.
	() Thanks