Degradation of ground surface area in older cars honda city idsi 2003-2008

Honday City IDSI 2003-2008 model is really a good car and of course the fuel economy is the best of all cars during its era and even after 17 years of driving the engine still feel great as if it still can last for another 30 years without major issue. 

However, there is one problem about the car after it is getting older - the diminishing effectiveness of the grounding surface area around the engine bay and chassis. This is of course due to rust, engine oil spill, dust, dirt and grimes. 

The resistance is so great that as if the car engine bay electrical grounding surface area is divided into two parts - where the battery part has its own grounding, and the fuse box has its own as well when they supposed to be working as one entity. 

As a result, poor electrical connections have significant bad impact to the overall engine performance of the Honda City IDSI such as 

• Delay gear shift
• Pickup acceleration delay
• Consume a little more fuel 
• Sluggish engine performance and sometimes very loud
• Car jerking badly when stopping at the traffic light while braking on gear D (Drive)
• Having difficult to start randomly (As if the battery is dead) empty crank
• Door lock sometimes difficult to open / lock by the remote control key

The above problems arise when the engine sensors, solenoids does not have sufficient current flow to communicate with the ECU / ECM / PCM.

• On the transmission there are sensors and solenoids that must have enough current to communicate effectively with the TCM (Transmission Control Module)
• On the engine side
• MAP Sensor (Mass Absolute Pressure)
• MAF Sensor (Mass Air Flow)
• Coolant Temperature Sensor
• IAT Sensor (Intake Air Temperature)
• DDVT Solenoid
• Knock sensor
• Oxygen Sensor
• ISCV 
• Camshaft position sensor
• Crankshaft position sensor
• Evaporative valve solenoid
• Throttle position sensor

All the engine sensors require efficient flow of current to communicate with the ECU without delay so that injectors, spark plugs are working effectively for combustion inside the engine. This is indeed true after adding one good copper wire for grounding the following improved significantly and making it feels like having new engine.

1. Gear shift delay - solved
2. Pick up acceleration - improved significantly feeling can chase any high speed car.
3. Fuel consumption is better
4. Car jerk reduce significantly when braking on traffic light while on gear D

What to do when the car feel sluggish and gear jerk

After years of driving suddenly you feel the car becoming sluggish and the gear starting to jerk especially when reverse or braking while on gear D. This is common behavior for most cars when it is getting old. So what is first thing to check when it happens. 

The most basic thing to look at is the battery connection - make sure nothing loosely tighten and if so tighten it accordingly. Loose battery connection can be the main culprit in sluggish car as the engine sensos such as;

MAF - Mass Air Flow Sensor

MAP - Manifold Absolute Pressure Sensor

IAT - Intake Air Temperature Sensore 

TPS - Throttle Position Sensor

ISCV - Idle Speed Control Valve

ECT - Engine Coolant Temperature Sensor

CMP - Camshaft Position Sensor

CKP - Crankshaft Position Sensor

OCV - Oil Control Valve Solenoid

Knock Sensor

As well the spark plugs, fuel injector, fuel pumps

The sensors and components above require efficient electrical signal to communicate them between Engine Control Unit (ECU / ECM / PCM) effectively.

Meanwhile on the transmission side the gearbox solenoids and sensors require efficient current to communicate with the transmission control unit (TCU). 

Therefore, make sure the battery connection is tightly.

Redundant nipple valve on the K3 or 3sz-ve engine block behind the catalytic converter

Earlier I was wondering what the redundant nipple valve, sticking out of the 3sz-ve engine block. Even daihatsu forum has no answer for this so I've searched and found the mechanic manual book for K3 engine and it turns out that is the cooling water drain plug. Not sure what is the common function of the nipple valve since the coolant drain can easily be done via the radiator drain plug and for the record that valve rarely being used by anyone in the lifetime servicing their K3 engine.

Idle RPM not going up when A/C turned on and it cause the car to vibrate (shaking)

This is quite an intriguing problem that I've not yet do some experiment. The idle is running at 750 RPM without accessories on especially the air conditioning system. Now the interesting part is when the A/C is on the idle RPM refuse to increase and stays at 750 RPM that result in the car to shake (vibrate) feeling like almost stalling. 

The problem is becoming moe intense when braking on traffic light while on gear D and when the A/C compressor kicks in the vibration becoming even more because the idle speed stays around 750 RPM. Why won't the RPM also increase dynamically based on the engine load? 

Suggested solutions:

1. Idle Speed Control Solenoid - dirty / malfunction

2. Adjust the throttle body cable to get more air?

3. Air conditioning gas is over charged thus the compressor magnetic coil consume more power to engage

Will need to experiment this one by one and see the outcome.

Shell Helix H7 5W-30 Semi Synthetic Engine Oil - It is really fuel economy as claimed by shell?

All these while I've been using Perodua 5W-30 semi synthetic engine oil for the past 12 years. Coincidentally there was a promotion for Shell Helix H7 5w-30 semi synthetic by a petrol station and it was RM20+ cheaper than perodua semi synthetic oil. So why not and got one bottle 4 Litres for a trial. 

To my surprise the shell helix h7 5w-30 which is less viscosity than the Perodua really does more fuel economy. The old alza has been consuming average of 12.3 L/100km using Perodua engine oil but the shell helix is able to reduce around 11.6 L/100km for city driving and 11.2 L/100km long distance journey. That is trully incredible an engine oil could really have significant impact to the fuel economy. 

Apart from that the engine feel lighter and easily pick up quickly - less hesitation. This is from personal experience and probably won't work on cars that is already have good fuel economy average but for an older car that have been consuming fuel, the shell helix h7 5w-30 probably could help. The normal price probably way more expensive than perodua semi synthetic but you are compensated on the day-to-day fuel consumptions over a time span of 6 months before the next engine oil change. If you calculate the cumulative saving on fuel probably outweigh the price of the shell helix h7. 

So that's all my honest review from an experience using the Shell Helix H7 5W30 semi synthetic for the first time. The next engine oil change probably I will still go for it despite of the price since I can save more on daily fuel consumptions.