Facing engine power loss & vibrations on my new Mahindra Thar

The car has no issues starting up or staying on. It is just the inconsistent revs and misfires causing the vibration.

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Bought the New Thar Petrol on 30/11/2021. The first automobile purchase completely impressed us. Went for a long highway intercity trip, a trip to the Eastern Ghats during chilly weather and many beach road drives. Thoroughly enjoyed all these times with the car.

Noticed a small issue where the car pulls to the left slightly though the steering is pointing straight. Other than that, everything felt perfect. The first service gave me a surprise in terms of Mahindra service centre reception at Automotive Manufacturers, thanks to Ms Gowthami (she brilliantly handled multiple customers in a very calm and composed way). Only until a day after the delivery when I noticed that the technical team wasn’t as impressive as the front desk team. The service reminder alert in the Instrument cluster wasn’t reset, the bonnet had remains of the glue stains from an accessory installation I requested and the unresolved issue of the vehicle pulling towards the left. They said their Alignment machine is not working and they’ll summon me after it is repaired. Kept following up for 2 weeks but they kept saying it was still under repair.

Then comes 01/01/2022 New Years Day. Considering it a very merry and auspicious day, I decided to take my parents for a small outing, Got them loaded, went to the Millenium HP Petrol Station and asked them to do a tank full. Everything was perfect and going, as usual, we took a small pitstop for lunch and resumed the drive.

We are still within the city and all of a sudden I notice some inconsistency with the acceleration, the engines response to the throttle was getting a little unpredictable while I was just going at city speeds of 20-40 km/h. I didn’t understand what was wrong and the issue seemed to have stopped so I continued for 2kms more and then noticed it even more significantly this time. I started noticing some weird misfire and vibrations. Not any audible noise, but significant vibrations which kept coming and going. Before I decided to indicate and stop by the left, I felt a sudden power loss and the OBD check lamp blinked about 5 times and though the ignition was on, the acceleration stopped working. Fortunately enough since there was a slope, I indicated and came and stopped to the left.

Turned on the hazards and by now though I was at neutral with the parking brake engaged, I could visible see the IRVM and the cabin vibrating vigorously. Even my parents could clearly notice something was wrong and some alternating vibrations which were creating a lot of horizontal movement, especially left-right movement. I got down and opened the hood to notice the engine shaking very violently every alternate second or two. The OBD check lamp was not glowing now. Turned off the engine by the side of a busy road and called RSA.

The RSA towing truck was taking too much time to arrive and we were causing unnecessary traffic congestion which forced me to start again and move. We travelled about 10kms after refuelling. And now we wanted to turn back and go home which is about 5 km. Slowly limped back home at a slow speed since the service centre told us they can’t work on the car until Monday anyway since it’s a long weekend holiday.

On Monday morning, the Automotive Manufacturers Service centre sent their driver to pick up the vehicle. He also noticed the weird and violent vibrations which are generally 0 in the Petrol Thar. The car has no issues starting up or staying on. It is just inconsistent revs and misfires causing the vibration.

I'm new here, can someone also please guide me to an appropriate thread where I can post more about the problem and get expert insights.

Here's what BHPian Maverick5490 had to say on the matter:

Since you mentioned this happened post refuelling the car, ask them to check the fuel quality. If there is water or contamination in the petrol, this can lead to improper combustion and misfiring.

Here's what BHPian vishy76 had to say on the matter:

Vibrations and misfiring on a vehicle as new as yours only points to faulty spark plugs or ignition coils usually. Get both of these checked. A scan will reveal which cylinder is misfiring and how many times it has misfired. Remove the spark plug on that one and check its condition.

If the plug itself is fine, swap the ignition coil from that cylinder to another one and see if the misfire code moves to the new cylinder. You do have (or did have) what I suppose is a CEL, so I don't think you need to worry much. You will have plenty of data (fault code itself, freeze frame data, number of misfires etc.) to determine what is wrong and solve the issue. It should be stored in the fault code history.

Here's what BHPian dipen had to say on the matter:

As a basic old school check:

• Can you please remove the spark plugs, clean them put them back again and check.
• If there is still an issue, remove the air filter, clean it put it back and try,

These are the most common causes that cause misfiring / juddering at idle as well. If these don't resolve, it may be related to some air intake piping or similar or any wiring getting short.

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