Nagging Engine Knocking in MPFI Zen - Help!

newcoolgadgets · 24th April 2007, 09:56

Hi All,

My 2006 Maruti Zen Vxi has developed a nagging engine knocking problem. When I rev up in 3rd and 4th gear, there is a loud 'kit-kit-kit' knocking sound from the engine. I have been to the Seva Maruti workshop (Nagpur), thrice in the last three months but the problem has not been resolved.

The first time the service advisor told me that it may be due to poor quality of fuel, and asked me to use up the entire fuel in the tank and then fill up with fresh fuel. I have always used BP Speed and never had any problems before. Still, I did as told but the knocking persisted. Then, I used up that tankful too and filled up from another pump to rule out bad fuel from my regular pump. But the knocking persisted.

The second time, Seva Maruti adjusted the engine timing, and the engine knocking did lessen, but still appeared at very high revs. I was told to drive for a few hundred kilometers and then report back. The knocking gradually increased and then re-appeared within a week, at medium high revs again.

The third time, Seva Maruti decided that it may be due to the tappets and did 'tappet adjustment'. They also changed all the spark plugs from Mico to Champion. After this, the knocking did subside, appearing only at very, very high revs. But after the 'tappet adjustment' , there was a more pronounced noise of the tappets. And now after 10 days of normal city driving, the engine knocking as re-appeared at medium high revs in 3rd and 4th gear!

I am at wit's end

as to what might be causing the knocking problem. Any help, suggestions, pointers are welcome.

- Rohit

Kaizer Sozay · 24th April 2007, 13:46

If you are from nagpur go & see Mr Zohur Hasan at Hasan garage in Sadar, He is a MASS. HE will be able to be a better job.
When i was in nagpur i used to service my car there

Axe · 4th May 2007, 18:10

You know, the same thing has happened to my accent gvs. The workshop told me its was because i used speed/premium fuels, and advised against using them. So i switched to normal fuel, and the problem did lessen, but came back agian. Now the service centre says it is because of bad fuel. I have tried to find a reliable outlet in andheri west in mumbai, but the knocking still continues. Don't understand what the problem is. Any suggestions from anyone?

chetanhanda · 9th May 2007, 03:29

Quote:

Originally Posted by newcoolgadgets

Hi All,

My 2006 Maruti Zen Vxi has developed a nagging engine knocking problem. When I rev up in 3rd and 4th gear, there is a loud 'kit-kit-kit' knocking sound from the engine. I have been to the Seva Maruti workshop (Nagpur), thrice in the last three months but the problem has not been resolved.

The first time the service advisor told me that it may be due to poor quality of fuel, and asked me to use up the entire fuel in the tank and then fill up with fresh fuel. I have always used BP Speed and never had any problems before. Still, I did as told but the knocking persisted. Then, I used up that tankful too and filled up from another pump to rule out bad fuel from my regular pump. But the knocking persisted.

The second time, Seva Maruti adjusted the engine timing, and the engine knocking did lessen, but still appeared at very high revs. I was told to drive for a few hundred kilometers and then report back. The knocking gradually increased and then re-appeared within a week, at medium high revs again.

The third time, Seva Maruti decided that it may be due to the tappets and did 'tappet adjustment'. They also changed all the spark plugs from Mico to Champion. After this, the knocking did subside, appearing only at very, very high revs. But after the 'tappet adjustment' , there was a more pronounced noise of the tappets. And now after 10 days of normal city driving, the engine knocking as re-appeared at medium high revs in 3rd and 4th gear!

I am at wit's end

as to what might be causing the knocking problem. Any help, suggestions, pointers are welcome.

- Rohit

hi, is your problem solved or are you still having this issue ?

mclaren1885 · 9th May 2007, 08:14

Check your timing .. Maybe you might be running lean , is the new zen distributor type ?? Also , ask them to check if your valve clearance is right .. Check if there is coolant in the radiator at all times and engine oil .. Check compression on each cylinder and that could probably give you some idea about the status of the engine .. Have you done any mods ?? Like increasing compression ??

Jaggu · 9th May 2007, 11:04

is this recent development or old one? as in slight knowcking was always there?

How many kms car has done?

damn this is a pain for zen had faced the same some 7 years back, do a check on the timing belt also if its off by one tooth ur timing will be way off.

do a thorough setting of tappets (when cold), ensure timing, and cooling is in order, flush engine and put new oil.

If car has run more than 40 k kms do a decrb also.

vaasu · 9th May 2007, 18:53

I had the similar knocking problem in my santro. Pick-up was down and engine felt strained.
Hooking up the ECM to the scanner did not show any errors.
Also, suprisingly the service advisor did not hear any knocking sound and found it normal!

Tried all tricks like resetting the ECM, changing fuel and all, but it did not help.

3 visits later I insisted that he change my ECM with a similar model(pre erlx) and test. Test drive with the changed ECM felt smooth, no knocking and pick-up was back to normal.
Again, surprisingly the service advisor did not find any difference between the drive as compared to the original ECM!

However, after plugging back my ECM, the engine felt smooth and there was no knocking.

Was it because ECM was not reset properly?
As expected, service advisor did not had an explanation...

Problem has not re-surfaced since then...

chetanhanda · 11th May 2007, 09:38

Quote:

Originally Posted by vaasu

I had the similar knocking problem in my santro. Pick-up was down and engine felt strained.
Hooking up the ECM to the scanner did not show any errors.
Also, suprisingly the service advisor did not hear any knocking sound and found it normal!

Tried all tricks like resetting the ECM, changing fuel and all, but it did not help.

3 visits later I insisted that he change my ECM with a similar model(pre erlx) and test. Test drive with the changed ECM felt smooth, no knocking and pick-up was back to normal.
Again, surprisingly the service advisor did not find any difference between the drive as compared to the original ECM!

However, after plugging back my ECM, the engine felt smooth and there was no knocking.

Was it because ECM was not reset properly?
As expected, service advisor did not had an explanation...

Problem has not re-surfaced since then...

Am I missing something here becoz what I have understood is that you decided to reset your ECU becoz you thought the engine was knocking ?

Plz can you explain why you felt that resetting your ECU is the way to go in case of knocking issue ? shouldnt you be looking at ignition timing, fueling etc etc? (Im sure u were not using a remapped ECU so whats the use ?)
Resetting is of no use, you will simply go back to default settings and lose DTC which may have been logged due to some problems , and when you start the car the ECU is going to again learn the values and store the DTCs if any ..so what is the point .. ?

Stock ECU from a standard production line car wont start acting up and start knocking issues unless you go and mess with something major with it ...

Can let us know your views ?

24th April 2007, 09:56	#1
newcoolgadgets BHPian Join Date: May 2006 Location: Nagpur Posts: 183 Thanked: 17 Times View My Garage	Nagging Engine Knocking in MPFI Zen - Help! Hi All, My 2006 Maruti Zen Vxi has developed a nagging engine knocking problem. When I rev up in 3rd and 4th gear, there is a loud 'kit-kit-kit' knocking sound from the engine. I have been to the Seva Maruti workshop (Nagpur), thrice in the last three months but the problem has not been resolved. The first time the service advisor told me that it may be due to poor quality of fuel, and asked me to use up the entire fuel in the tank and then fill up with fresh fuel. I have always used BP Speed and never had any problems before. Still, I did as told but the knocking persisted. Then, I used up that tankful too and filled up from another pump to rule out bad fuel from my regular pump. But the knocking persisted. The second time, Seva Maruti adjusted the engine timing, and the engine knocking did lessen, but still appeared at very high revs. I was told to drive for a few hundred kilometers and then report back. The knocking gradually increased and then re-appeared within a week, at medium high revs again. The third time, Seva Maruti decided that it may be due to the tappets and did 'tappet adjustment'. They also changed all the spark plugs from Mico to Champion. After this, the knocking did subside, appearing only at very, very high revs. But after the 'tappet adjustment' , there was a more pronounced noise of the tappets. And now after 10 days of normal city driving, the engine knocking as re-appeared at medium high revs in 3rd and 4th gear! I am at wit's end as to what might be causing the knocking problem. Any help, suggestions, pointers are welcome. - Rohit
	() Thanks

24th April 2007, 13:46	#2
Kaizer Sozay BHPian Join Date: Apr 2005 Location: Melbourne Posts: 333 Thanked: 5 Times View My Garage	If you are from nagpur go & see Mr Zohur Hasan at Hasan garage in Sadar, He is a MASS. HE will be able to be a better job. When i was in nagpur i used to service my car there
	() Thanks

4th May 2007, 18:10	#3
Axe Newbie Join Date: Dec 2006 Location: Mumbai Posts: 18 Thanked: Once	You know, the same thing has happened to my accent gvs. The workshop told me its was because i used speed/premium fuels, and advised against using them. So i switched to normal fuel, and the problem did lessen, but came back agian. Now the service centre says it is because of bad fuel. I have tried to find a reliable outlet in andheri west in mumbai, but the knocking still continues. Don't understand what the problem is. Any suggestions from anyone?
	() Thanks

9th May 2007, 08:14	#5
mclaren1885 BANNED Join Date: Jul 2005 Location: Bangalore (the city of modded cars) !! Posts: 4,820 Thanked: 45 Times View My Garage Infractions: 0/1 (10)	Check your timing .. Maybe you might be running lean , is the new zen distributor type ?? Also , ask them to check if your valve clearance is right .. Check if there is coolant in the radiator at all times and engine oil .. Check compression on each cylinder and that could probably give you some idea about the status of the engine .. Have you done any mods ?? Like increasing compression ??
	() Thanks

9th May 2007, 11:04	#6
Jaggu Team-BHP Support Join Date: May 2004 Location: Bangalore Posts: 20,215 Thanked: 15,907 Times	is this recent development or old one? as in slight knowcking was always there? How many kms car has done? damn this is a pain for zen had faced the same some 7 years back, do a check on the timing belt also if its off by one tooth ur timing will be way off. do a thorough setting of tappets (when cold), ensure timing, and cooling is in order, flush engine and put new oil. If car has run more than 40 k kms do a decrb also.
	() Thanks

9th May 2007, 18:53	#7
vaasu BHPian Join Date: Mar 2004 Location: Pune Posts: 156 Thanked: 169 Times	I had the similar knocking problem in my santro. Pick-up was down and engine felt strained. Hooking up the ECM to the scanner did not show any errors. Also, suprisingly the service advisor did not hear any knocking sound and found it normal! Tried all tricks like resetting the ECM, changing fuel and all, but it did not help. 3 visits later I insisted that he change my ECM with a similar model(pre erlx) and test. Test drive with the changed ECM felt smooth, no knocking and pick-up was back to normal. Again, surprisingly the service advisor did not find any difference between the drive as compared to the original ECM! However, after plugging back my ECM, the engine felt smooth and there was no knocking. Was it because ECM was not reset properly? As expected, service advisor did not had an explanation... Problem has not re-surfaced since then...
	() Thanks