[ravi@64bhp]

I have a Wagon-R Lxi with 32000 mileage on odo. For the past 4 months, I have been using the car in just weekends around 50 km. In the week days, it is just lying idle, most of the time with petrol more than half a tank.

Since past week, I have been experiencing jerking when I press accelerator. It is obvious most of the time in 1, 2, and 3 gears. It seems to be fine in higher RPMs. Some times the car runs smooth without any problem. The jerking starts all of a sudden when go to lower gears and try to accelerate. At that, even if I press pedal to floor, the car wont get acceleration.

I do not think it is because of bad fuel, as it runs smooth most of the time.

Is this any sign of completely worn out clutch?? Is there something seriously wrong with my car?? Fuel efficiency seems to be okay. Acceleration decreased a bit but it is expected as my car has done around 32000 km.

I am not getting time to take my car to a service station, as have been really busy. What could be causing this problem?

Thanks in advance.

[deepgautam_qa]

Get the throttle cleaned...jerking as you accelerate might be linked to it...also get your spark plugs checked. BTW are you running on an alternate fuel (LPG/CNG)?

Cheers,
Deepak

[ravi@64bhp]

Originally Posted by deepgautam_qa

Get the throttle cleaned...jerking as you accelerate might be linked to it...also get your spark plugs checked. BTW are you running on an alternate fuel (LPG/CNG)?

Cheers,
Deepak

Deep, my car is not running on LPG/CNG. Have been using normal petrol from a reliable petrol pump (same pump since past two years) with Iftex SystemG. My car has been running smoother with Iftex SystemG and I have been using this for the past one-and-half year.

What I was wondering is why this knocking is coming in at intervals. One more observation, the knocking is more when a/c is on.

[predatorwheelz]

Knocking is a result of the air-fuel mixture in the engine detonating/exploding outside the engine's typical combustion cycle. I suggest the following remedies:

1) Lower fuel might be going into the cylinder due to clogged injectors. Check the fuel injection system in the car. (such a problem disappears at higher RPMs since more fuel is pushed into the mixture).

2) Check the spark plugs. Often, clogged or burnt spark plugs lead to incorrect/incomplete combustion, leading to knocking.

[Astleviz]

may not be relevant but I had a similar problem with my ford ikon a while ago and the ignition coil was at fault. Here is what I suggest you do-

1. Check and clean the fuel filter and spark plugs.
2. If problem persists, check and clean the throttle body and injectors.
3. If the problem is still there, replace the ignition coil from another working car to see if that helps.

[ravi@64bhp]

Originally Posted by predatorwheelz

Knocking is a result of the air-fuel mixture in the engine detonating/exploding outside the engine's typical combustion cycle. I suggest the following remedies:

1) Lower fuel might be going into the cylinder due to clogged injectors. Check the fuel injection system in the car. (such a problem disappears at higher RPMs since more fuel is pushed into the mixture).

2) Check the spark plugs. Often, clogged or burnt spark plugs lead to incorrect/incomplete combustion, leading to knocking.

Seems logical. I would check that. But, most of the time the car runs smooth, even in lower rpms. It comes occasionally when I down shift to lower gears all of a sudden. If the injectors are blocked, the problem should have been persisted all the while right?

[predatorwheelz]

Originally Posted by ravi@64bhp

Seems logical. I would check that. But, most of the time the car runs smooth, even in lower rpms. It comes occasionally when I down shift to lower gears all of a sudden. If the injectors are blocked, the problem should have been persisted all the while right?

Not necessarily. At a steady engine speed (regardless of whichever RPM) the injectors have to deal with a steady fuel flow. However, once you downshift, the drastic increase in engine speed necessitates an immediate jump in the flow. It might be possible that the injectors are marginally blocked. So they have no problems in handling regular fuel flow, only drastic increase in flow is a problem.

[bblost]

http://www.team-bhp.com/forum/techni...-r-knocks.html

[ravi@64bhp]

Originally Posted by Astleviz

may not be relevant but I had a similar problem with my ford ikon a while ago and the ignition coil was at fault. Here is what I suggest you do-

1. Check and clean the fuel filter and spark plugs.
2. If problem persists, check and clean the throttle body and injectors.
3. If the problem is still there, replace the ignition coil from another working car to see if that helps.

Astleviz, I will do all these steps. Thank you!!

Originally Posted by predatorwheelz

Not necessarily. At a steady engine speed (regardless of whichever RPM) the injectors have to deal with a steady fuel flow. However, once you downshift, the drastic increase in engine speed necessitates an immediate jump in the flow. It might be possible that the injectors are marginally blocked. So they have no problems in handling regular fuel flow, only drastic increase in flow is a problem.

Thanks predatorwheelz!!! Got some good inputs as to what might have happened. Will take my car to the service station this weekend.

[ravi@64bhp]

Originally Posted by bblost

http://www.team-bhp.com/forum/techni...-r-knocks.html

Hi, I do not think my problem is related to the thread you have posted. My car's temperature is fine. I do not see any overheating. Anyway thanks for the thread. Got some inputs from it.

[ravi@64bhp]

Yesterday, I serviced my car at MASS and the cause for the knocking, they found, is clogged spark plugs. They cleaned the plugs and the car is very much fine without any misfiring.

[predatorwheelz]

Originally Posted by predatorwheelz

Check the spark plugs. Often, clogged or burnt spark plugs lead to incorrect/incomplete combustion, leading to knocking.

Originally Posted by ravi@64bhp

Yesterday, I serviced my car at MASS and the cause for the knocking, they found, is clogged spark plugs. They cleaned the plugs and the car is very much fine without any misfiring.

Yipee! Always glad to know that my advice has been of any help!

[Psycho]

Originally Posted by ravi@64bhp

Yesterday, I serviced my car at MASS and the cause for the knocking, they found, is clogged spark plugs. They cleaned the plugs and the car is very much fine without any misfiring.

A knock sounds like a hammer hitting something solid. This was more of a misfire.

[ravi@64bhp]

Originally Posted by predatorwheelz

Yipee! Always glad to know that my advice has been of any help!

Thank you so much!!!!

Originally Posted by Psycho

A knock sounds like a hammer hitting something solid. This was more of a misfire.

Oh! Thanks for clarification. Yeah! I would definitely say it as a misfiring. Now I understood clearly what is a misfire and what is a knock.

[Swift]

Hi All, I am having a similar issue with my 2005 WagonR as described in this thread. Need your opinion. Here's my story -
I had a dent, an old one, on my left front door and got it repaired by the Maruti body shop. When I gave my car, the fuel level was almost at red line. I drove the car for about 6KM, then refilled full tank at my regular gas station. Next day, I drove 18 KM to my office and everything is fine till now. In the evening when I started driving, I could feel the jerking/knocking in 1st, 2nd, 3rd gears, felt like car might get switched off. This was not happening all the time, but it feels serious with the car jumping and all.
Now, pls tell me, should I take the car to service station immediately or wait till I can refuel my car?
Thank you guys.