Hello,
I am driving a 8 year old Mazda2-Salon. Quite recently, I am observing the following in the car and need your help to identify the potential causes :

1. While starting to drive, I observed only half the power as before, until I hit like 40 kmph speed and above.
2.While slowing down it is not losing speed evenly, instead there looks to be a sudden reduction in speed.
3. Upon pressing the brakes fully, the steering is vibrating a bit.
4. At low speed, there are frequent metal rubbing like sound from inside, mostly when I accelerate.
Recently, I also observe that the kmpl has started to drop gradually. On making a quick check at my servicing center, I was mentioned that the ECS was down and has been restarted, but the OBD flagged nothing wrong.

Kindly let me if anyone has faced these issues before and fixed them / any suggestions on what should I do next.

Thanks !

 

Hello, Prasantha092.

I have never owned nor driven that vehicle, however! In response to both what you said and the four items listed:
I am very surprised that the business you took your vehicle to did not visually inspect some components or simply had nothing to say about your observations/complaints/issues.

1. To assist in determing the loss of power: I would highly recommend investing in an OBD II reader / scanner tool; the reason? To observe live data from the sensors during operation (you can safely plug it in and the device should save a reviewable log for after the test drive). Try driving regularly, then conservatively and then erratically when it is safe to do so (such as WOT (wide open throttle); meaning to start at a low speed and press the accelerator pedal all the way to the floor and allow the vehicle to get up to a target speed)).

You could also test the compression of the individual cylinders (through the spark plugs). You will need to find the proper and expected compression values on a technical or workshop manual for your vehicle.

In short: The cylinders, cylinder's valves and piston's rings are common culprits of compression loss. The air intake manifold, an airline hose or other component might also be responsible (such as a brake line). These are quick and easy to visually inspect; in order to test the valves: You would need to disassemble part of the engine (such as removing the air intake manifold) and then using a special tool in conjunction with an air compressor measure the air-compression-loss per cylinder (which would be the valves leaking).

Other possible causes could be the air-fuel mixture in the cylinder or malfunctioning sensors pertaining to these sub-systems and lastly the electrical system. The best route (initially) would be to query data from the onboard computer (OBD II) and assume the data displayed is honest and true and work from there.

2. I would immediately check the brake pads, the brake cylinder (for any kind of damage) and then the brake reservoir; is it between MIN and MAX? Is the fluid dirty and fouled? If all is well: You might have air bubbles in the brake lines! Hydraulic fluid is hard to compress, but air is easily compressible. You would need to bleed (remove) the air from the brake system. You can gravity-bleed the system or use a vacuum tool (hand-vacuums are sold relatively cheap and are easy to use).

It could be a culmination of the above and/or the automatic transmission down shifting abruptly. Try to safely observe your tachometer (or record the data with an OBD II reader with live data readings) and go for a test drive; when you apply the brakes at speed XYZ: Do the brakes slow the vehicle down the same or does the tachometer change rapidly (gear change; engine braking) as you're applying the brakes?

3. That is SCARY! That could be a misalignment of the vehicle, the tires themselves (unbalanced and/or dirty; wet sand in the rims/wheels will cause such imbalances), bad swaybar links and possibly tie rods. All of these components are apart of the steering-and-suspension of the vehicle and all play a subtle part.

The steering wheel vibrates due to the rack-and-pinion system that connects everything together to allow you to steer (there is possibly another system, but I am unsure of your vehicle's design). That is alarming. Stopped vehicles are safer than vehicles in motion that do not stop.

4. "Metal rubbing-like sounds" could be just about anything! A free floating firewall piece, a bad rubber gromet suspending the catalytic converter's catback system, a brake pad's metal tab (wear indicator), a bad pulley (alternator, waterpump, idler, harmonic balancer, serpentine belt tensioner or other); it could be noise from the belt slipping and rubbing on the metal engine! That's a very vague description without much else to work on. It could be the engine timing chain inside or oil pump chain inside. It might even be the cylinders scraping the inside of the engine's walls! Very bad.

The good news is that you said it's at low speeds, but what about high speeds?


I hope this helps.

A minor issue like that could grow exponentially, depending on what it is (the 'metal noise'). Total catastrophic failure (this isn't a scare tactic: Please keep that in mind; metal shouldn't rub on metal).