S10 engine revving on its own

16v100bhp · 10th December 2006, 13:23

The 1.6 on my S10 started revving on its own.

When the engine is revved to 2500 or more rpm it will come back to a 1000 and will start to rev on its own till 3500 and back. it keps doing this untill i rev again after which most times it stops and behave normally. I'm not sure whats wrong. Could it be the oxygen sensor?

FYI... the car is installed with a Typhoon filter and freeflows. I'm not sure if the air flow sensors get over excited is causing this problem. Please advice

moralfibre · 10th December 2006, 13:41

This was a defect in a certain lot of Palio's. Get the stepper motor and the throttle body cleaned and it should be fine for sometime until it recurs. The permanent fix is to have the throttle body replaced.

16v100bhp · 10th December 2006, 14:00

Quote:

Originally Posted by moralfibre

This was a defect in a certain lot of Palio's. Get the stepper motor and the throttle body cleaned and it should be fine for sometime until it recurs. The permanent fix is to have the throttle body replaced.

Thanks Moral for the quick response. Although I'm not exactly sure of what u meant by the throttle body or the stepper motor, i hope i could use the same terminology at the workshop. But i would defenitely appreciate it if you could give me some more details on these.

Also do you think this has got something to do with the K&N's? I'm also thinking of doing an engine flush? (OWS) Do you think this would help.

moralfibre · 10th December 2006, 17:35

No, K&N is not causing the problem. A friend working for Fiat showed me multiple examples of cars having this particular problem and they could only have solutions as mentioned in my previous. Even if you swap throttle bodies of two cars having this issue, the problem vanishes (Believe it or not I have had a practical demonstration on this).

If your car has done more than 15-20k kms, then an Engine flush is not recommended since it has a tendency to flush out carbon deposits from within the engine. There are carbon deposits which hold up old and worn out oil seals and gaskets which prove to be useful for having a non leaky engine. When you use an engine oil flush, you might drive these deposits out and have a leaky engine. I am not sure whether your engine will leak oil but I feel it may.

16v100bhp · 11th December 2006, 00:33

Ok! Thanks again Moral...

Let me try cleaning up the "Throttle body and the stepper motors" as you had mentioned. I will defenitely let you know the outcome of this soon

16v100bhp · 11th December 2006, 00:37

Quote:

Originally Posted by moralfibre

If your car has done more than 15-20k kms, then an Engine flush is not recommended since it has a tendency to flush out carbon deposits from within the engine. There are carbon deposits which hold up old and worn out oil seals and gaskets which prove to be useful for having a non leaky engine. When you use an engine oil flush, you might drive these deposits out and have a leaky engine. I am not sure whether your engine will leak oil but I feel it may.

Logicaly thinking this could be true

team dragstar · 11th December 2006, 18:40

and get to a fiat authorised dealer for this please... also check the map sensors and the vaccum lines on f i c t pump

ankitahuja · 11th December 2006, 20:28

I faced a very similar problem with my OHC. I got the throttle body cleaned nicely and its perfect since then. The problem will only increase if you dont get this done, and getting the throttle cleaned isnt an expensive affair at all too!

16v100bhp · 11th December 2006, 20:43

Quote:

Originally Posted by team dragstar

and get to a fiat authorised dealer for this please... also check the map sensors and the vaccum lines on f i c t pump

Ok.. i'll try the Tata fiat dealer here. think its concord. Thank You!

16v100bhp · 24th December 2006, 09:18

Hi guyz!! I finally got my throttle body and induction cleaned. We also noticed that there was a crack in the induction pipe!

(seems to have sucked in a lot of dirt). Anyways i got it replaced now.

The engne is running fine as of now. Didnt have the revving problem again. But i havent run more than 20k after the fix it. I'll let you guyz know if everything turns out fine.

BTW the guyz didnt have throttle cleaning spray. They did it with paint thinner

.

16v100bhp · 3rd January 2007, 14:22

Hey guyz,
The auto revving started again last week...This time I got the map sensor replaced from another 1.6 which was laying at the workshop. The problem still continued even with the changed sensor.

Now, what i noticed yesterday was that the problem only starts when the engine gets hot and the main cooling starts running. This is my theory here. Please let me know what you guys think about it..
The Engine gets hot - The main cooling fan start working there by spreading some hot air into the engine compartment - The open air filter (K&N Typhoon filters) placed just to the left of the engine sucks in hot air - The sensors gets confused since the oxygen density would be comparitively very low and makes the engine to rev more asking for more air - The rpm goes down again once it gets the required oxygen level - and the cycle continues.
I'm not very sure on why the rpm goes down but this is more of my intution. Now If this is true all i would need to do is shift the filters some where down, may at the sides of the bumper OR may be get a partition/ice box kind of stuff setup at the current location of the filters so that the hot air doesnt get mixed with the fresh air from outside.

I'm planning to test it for some more days to confirm my finding, Please let me know what you guys think...

Sideways · 3rd January 2007, 14:38

Ahmed, as sugested please have your stepper motor cleaned / replaced. this should sort out the problem.

bhavit46 · 18th January 2007, 14:59

Hi! 16v100bhp. I also own a Palio S10 and was faced with exactly the same problem that you have mentioned.
When the second cooling fans goes on the rpm goes up. After a lot of trial and error with the throttle body and replacing the oxygen sensors, I found that the problem was not due to the second cooling fan.
The problem of engine revving is due to the quality of fuel. Palio has a high compression ratio and needs a higher octane fuel and when the engine does not get that fuel, there is 'gumming' in the fuel injector.
So i would recommend using system-G every time you fill up the fuel tank and use fuel injector cleaner once in every four times you fill the tank up.
I hope this should solve your problem, it has solved mine...

himanshugoswami · 18th January 2007, 15:14

I have htis problem as well with my Palio 1.2 ELX.

Took it to Concorde and Manipal but htese guys could not figure out why there is a problem.

Now they have told me to get the ECU changed !!!!!

bhavit46 · 18th January 2007, 15:24

Hi! Himanshu. I don't think there is a problem with the ECU. Try and get the throttle body clean with any throttle and carb cleaner spray.
Once you are done with it, use system-g (petrol additive) everytime you fill up the petrol and if possible also get the car's injectors clean once in every six months (only for 1.2l engine, more frequently for the 1.6l engine)
I hope this should solve the problem.
I got to this conclusion after doing many trials at Tej Motors, Ahmedabad.

10th December 2006, 13:23	#1
16v100bhp BHPian Join Date: Sep 2005 Location: Middletown CT USA Posts: 329 Thanked: 11 Times View My Garage	S10 engine revving on its own The 1.6 on my S10 started revving on its own. When the engine is revved to 2500 or more rpm it will come back to a 1000 and will start to rev on its own till 3500 and back. it keps doing this untill i rev again after which most times it stops and behave normally. I'm not sure whats wrong. Could it be the oxygen sensor? FYI... the car is installed with a Typhoon filter and freeflows. I'm not sure if the air flow sensors get over excited is causing this problem. Please advice
	() Thanks

10th December 2006, 13:41	#2
moralfibre Team-BHP Support Join Date: Dec 2004 Location: MH-12 Posts: 8,452 Thanked: 13,974 Times	This was a defect in a certain lot of Palio's. Get the stepper motor and the throttle body cleaned and it should be fine for sometime until it recurs. The permanent fix is to have the throttle body replaced.
	() Thanks

10th December 2006, 17:35	#4
moralfibre Team-BHP Support Join Date: Dec 2004 Location: MH-12 Posts: 8,452 Thanked: 13,974 Times	No, K&N is not causing the problem. A friend working for Fiat showed me multiple examples of cars having this particular problem and they could only have solutions as mentioned in my previous. Even if you swap throttle bodies of two cars having this issue, the problem vanishes (Believe it or not I have had a practical demonstration on this). If your car has done more than 15-20k kms, then an Engine flush is not recommended since it has a tendency to flush out carbon deposits from within the engine. There are carbon deposits which hold up old and worn out oil seals and gaskets which prove to be useful for having a non leaky engine. When you use an engine oil flush, you might drive these deposits out and have a leaky engine. I am not sure whether your engine will leak oil but I feel it may.
	() Thanks

11th December 2006, 00:33	#5
16v100bhp BHPian Join Date: Sep 2005 Location: Middletown CT USA Posts: 329 Thanked: 11 Times View My Garage	Ok! Thanks again Moral... Let me try cleaning up the "Throttle body and the stepper motors" as you had mentioned. I will defenitely let you know the outcome of this soon
	() Thanks

11th December 2006, 18:40	#7
team dragstar BHPian Join Date: May 2006 Location: mumbai Posts: 80 Thanked: 0 Times View My Garage	and get to a fiat authorised dealer for this please... also check the map sensors and the vaccum lines on f i c t pump
	() Thanks

11th December 2006, 20:28	#8
ankitahuja BHPian Join Date: Oct 2006 Location: Gurgaon Posts: 921 Thanked: 94 Times View My Garage	I faced a very similar problem with my OHC. I got the throttle body cleaned nicely and its perfect since then. The problem will only increase if you dont get this done, and getting the throttle cleaned isnt an expensive affair at all too!
	() Thanks

24th December 2006, 09:18	#10
16v100bhp BHPian Join Date: Sep 2005 Location: Middletown CT USA Posts: 329 Thanked: 11 Times View My Garage	Hi guyz!! I finally got my throttle body and induction cleaned. We also noticed that there was a crack in the induction pipe! (seems to have sucked in a lot of dirt). Anyways i got it replaced now. The engne is running fine as of now. Didnt have the revving problem again. But i havent run more than 20k after the fix it. I'll let you guyz know if everything turns out fine. BTW the guyz didnt have throttle cleaning spray. They did it with paint thinner .
	() Thanks

3rd January 2007, 14:22	#11
16v100bhp BHPian Join Date: Sep 2005 Location: Middletown CT USA Posts: 329 Thanked: 11 Times View My Garage	The problem is back... Hey guyz, The auto revving started again last week...This time I got the map sensor replaced from another 1.6 which was laying at the workshop. The problem still continued even with the changed sensor. Now, what i noticed yesterday was that the problem only starts when the engine gets hot and the main cooling starts running. This is my theory here. Please let me know what you guys think about it.. The Engine gets hot - The main cooling fan start working there by spreading some hot air into the engine compartment - The open air filter (K&N Typhoon filters) placed just to the left of the engine sucks in hot air - The sensors gets confused since the oxygen density would be comparitively very low and makes the engine to rev more asking for more air - The rpm goes down again once it gets the required oxygen level - and the cycle continues. I'm not very sure on why the rpm goes down but this is more of my intution. Now If this is true all i would need to do is shift the filters some where down, may at the sides of the bumper OR may be get a partition/ice box kind of stuff setup at the current location of the filters so that the hot air doesnt get mixed with the fresh air from outside. I'm planning to test it for some more days to confirm my finding, Please let me know what you guys think...
	() Thanks

3rd January 2007, 14:38	#12
Sideways BHPian Join Date: Nov 2004 Location: Madras - India Posts: 641 Thanked: 31 Times View My Garage	Ahmed, as sugested please have your stepper motor cleaned / replaced. this should sort out the problem.
	() Thanks

18th January 2007, 14:59	#13
bhavit46 BHPian Join Date: Mar 2006 Location: Ahmedabad Posts: 66 Thanked: 18 Times	Hi! 16v100bhp. I also own a Palio S10 and was faced with exactly the same problem that you have mentioned. When the second cooling fans goes on the rpm goes up. After a lot of trial and error with the throttle body and replacing the oxygen sensors, I found that the problem was not due to the second cooling fan. The problem of engine revving is due to the quality of fuel. Palio has a high compression ratio and needs a higher octane fuel and when the engine does not get that fuel, there is 'gumming' in the fuel injector. So i would recommend using system-G every time you fill up the fuel tank and use fuel injector cleaner once in every four times you fill the tank up. I hope this should solve your problem, it has solved mine...
	() Thanks

18th January 2007, 15:14	#14
himanshugoswami Senior - BHPian Join Date: Oct 2004 Location: !!!! Posts: 2,303 Thanked: 2,619 Times	I have htis problem as well with my Palio 1.2 ELX. Took it to Concorde and Manipal but htese guys could not figure out why there is a problem. Now they have told me to get the ECU changed !!!!!
	() Thanks

18th January 2007, 15:24	#15
bhavit46 BHPian Join Date: Mar 2006 Location: Ahmedabad Posts: 66 Thanked: 18 Times	Hi! Himanshu. I don't think there is a problem with the ECU. Try and get the throttle body clean with any throttle and carb cleaner spray. Once you are done with it, use system-g (petrol additive) everytime you fill up the petrol and if possible also get the car's injectors clean once in every six months (only for 1.2l engine, more frequently for the 1.6l engine) I hope this should solve the problem. I got to this conclusion after doing many trials at Tej Motors, Ahmedabad.
	() Thanks