[Vibhanshu]

The jerks seem to be uneven (i could not find a common time gap between two jerks). Putting the gear in neutral and accelerating does not produce any jerk

I faced a similar issue in my 2014 Fiesta 1.5 Diesel. The symptoms were stutter on acceleration. Wouldn't happen all the time but randomly. More pronounced over flyovers etc.

I went to Ford and got everything diagnosed etc. But all was fine! Finally, it went away for me on it's own and in retrospective I think it was faulty fuel maybe? I'd say it was a near miss for me and car never gave problem ever since then.

My advise, from my personal experience, refuel the car at a different petrol pump but only when your tank is 99% empty. All the best!

[shankar.balan]

@Tamarind

I posted something similar on the High Octane Fuel thread.
I has a similar experience with my Mini Cooper when it was about 8.5 or 9 years of age.
More detailed stuff appears on that thread if you wish to read it.

https://www.team-bhp.com/forum/showt...ferrerid=24593 (Speed 97 and High RON petrol discussion thread)

[swunkjyn]

@Tamarind, was the issue resolved. Do keep us posted on the what the exact issue was and how you resolved it.

[Turrrb0]

Originally Posted by Tamarind

He inspected and changed all 4 spark plugs - instantly the jerk frequency and intensity reduced. But still not completely gone.

Not sure if I had the same issue. But at times for me, my santro also used to jerk(misfire) sometimes while accelerating. It wasn’t a continuous shuddering or shaking but felt like a sudden flat spot in the power band. Changing the plugs and high tension plug cables sorted the issue for me. It hasn’t happened since. Now that your plugs are already new get the cables changed too.

Being that your car has done a lakh km and I’m assuming they’ve not been changed before, they’re dirt cheap and even a noob can change them all in 5 minutes. Give that a try before spending any serious money.

My 2p.

[grosserimperial]

It's either the Ignition Coil or Idle Control Valve. Our earlier Santro and current Eon developed these issues and were resolved after changing the ignition coil

[ganeshk4]

I have faced similar issue on my maruti zen. Local FNGs have suspected spark plugs and fuel pumps. And the issue would go away for sometime to resurface again. In my case it was the spark plug distributor which was dying. Nobody was able to fix it until it went complete dead.

[Asoon]

Start with Spark plugs if ok, then check ignitors (Ignition coil) if ok then check fuel/ air filter, if ok then check O2 Sensor if ok then timing belt,

If you are feeling RPM fluctuation in idle, drop in pick up, frequent mis-fires, low pickup in low RPMs then get O2 sensor check first

[tejasnaidu]

I have 2003 dec model santro xing, still have it. In 2010 Faced similar issue. After multiple follow ups with service centre found issue to be connecter for MAP sensor (Manifold pressure and temperaure) mounted on throttle body. Since replacing connector involved replacing entire harness, replaced connector only after joining wire.

Check MAP sensor connector.
Next check MAP sensor (Costs approx 3K-- new).

Also check IAC actuator. 60 days back housing/Body cracked causing air leakage from actuator and drop in pickup and milage. Temp fixed by applying silicon sealant but need to replace. Cracked IAC actuator will cause air leakage hissing sound.

[Tamarind]

Originally Posted by swunkjyn

@Tamarind, was the issue resolved. Do keep us posted on the what the exact issue was and how you resolved it.

Originally Posted by Turrrb0

Now that your plugs are already new get the cables changed too.

My 2p.

Originally Posted by grosserimperial

It's either the Ignition Coil or Idle Control Valve. Our earlier Santro and current Eon developed these issues and were resolved after changing the ignition coil

Originally Posted by ganeshk4

I have faced similar issue on my maruti zen. Local FNGs have suspected spark plugs and fuel pumps. And the issue would go away for sometime to resurface again. In my case it was the spark plug distributor which was dying. Nobody was able to fix it until it went complete dead.

Originally Posted by Asoon

Start with Spark plugs if ok, then check ignitors (Ignition coil) if ok then check fuel/ air filter, if ok then check O2 Sensor if ok then timing belt,

If you are feeling RPM fluctuation in idle, drop in pick up, frequent mis-fires, low pickup in low RPMs then get O2 sensor check first

Originally Posted by tejasnaidu

Check MAP sensor connector.
Next check MAP sensor (Costs approx 3K-- new).

Also check IAC actuator. 60 days back housing/Body cracked causing air leakage from actuator and drop in pickup and milage. Temp fixed by applying silicon sealant but need to replace. Cracked IAC actuator will cause air leakage hissing sound.

Originally Posted by kvsneela

There is no direct solution for these kind of problems. Since the car is 13 years( and 1 lakh km) old , all the old compenents might be losing their efficiency and these are ( sputtering and dying) is the symptom. But which component is the difficult to pinpoint. One side we have fuel line ( bad quality petrol, weak fuel pump and filter , clogged injectors ,etc,.) and other side air filter, in take manifold, all the sensors on the way, and then ignition system with ignition coils, sparkplugs , timing chain etc ,.
If one by one is changed we can see improvement because the old parts were not working with full efficiency. Modern IC engines can run 2 lakh kms easily but it requires support from other components with full efficiency. If the car is serviced in big dealership where they have similar models and can swap components trial and error and find the culprit. In case of FNG we have to buy new parts only ( also trail and error). If we find real problem with 10th component ,we might have replaced 9 components unnecessarily and expenditure may be more than the resale value of the car. Also since it is 2009 model , in 2 years RTO roadworthiness certificate will be required. In case of any old cars , the time to consider changing the car is the time the car starts giving major problem .

Thank you all for the inputs and suggestion,
Your inputs was very helpful in having guided conversations with the service center & my private mechanic

I decided not to go via the path of R&D in replacing parts (since the minimum quotation given was more than 10k considering parts + labor)

I have been maintaining the car in top shape but was noticing the slow and steady rise in maintenance costs for the past 3 years (especially after covid). Costs being aside, this breakdown aggravated the instinct of buying a new vehicle to have a peace of mind for the next 10 years

I ended up exchanging the car for 1.5L in a Tata motors showroom (i got an offer of 1.7L outside but decided to go with a branded company to avoid documentation hassles) and bought a TATA Tiago XZ+

Waited till i got the delivery to post this reply. Sorry for the delay !

When i compare my 13 year old customer purchase experience with Hyundai and the ergonomics of the machine Santro with the 2022 experience given by Tata and the ergonomics of the machine Tiago - The differences were striking in the face (both pros and cons)

Will write about them in detail with pictures soon
Once again Thank you all, for the thoughts and sharing your experiences - you guys rock