Engine overhaul

hoboonhua

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1st things 1st. When was the last time you changed spark plugs and change ignition coil? Has there been any feedback that your engine lao you? When was the last time you cleaned your throttle body?

At your car's age, 1st thing you should be looking at is change spark plugs, change ignition coil, change gasket and clean throttle body ... then reset ECU and monitor ... from the 3rd or 4th tank of petrol onwards after your ECU gets used to your driving habits either you will see improvement or if you don't then you've got bigger problems.

2nd hand car, not sure when the spark plugs and ignition coil were changed.
Just changed the gasket and clean throttle body recently. My mechanic checked and said spark plugs and ignition coil were good, dont need to change..
 

hoboonhua

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Sienta has a 42L petrol tank IIRC. You're getting about 450KM which makes your rough FC ~11KM/L. This really isn't so bad unless you do a lot of smooth flowing highway driving and very little city KMs.

The cost of an overhaul is substantial and there is vehicle downtime involved as well. It should only be considered in the event that you are experiencing serious engine trouble, major oil leaks, overheated your engine badly etc. Unless you're getting like 7KM/L, it makes no sense to consider an engine overhaul especially for a 10 year old car. If you're renewing it for another 10 years when it's 20, that might be more viable but I have a feeling no one is that attached to their Sienta.. :o

yesterday car fuel gauge showed about 10% left... went to petrol station to pump full tank, but only managed to pump 28l ... some how the fuel gauge is not accuracy..
 

xiaozhi86

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Don't think too much. 11km per litre I feel is normal lah. Old car old technology. How much fuel saving you want?

Want save fuel go get new car or diesel car
 

Z_Dash

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Dun overhaul for the sake of doing because everyone done so.

You need to know what problems you have and what this "overhaul" will solve.

It's not just a spark plug replacement and not just trust workshop as they apply general theory to all cars they service......you know best what is needed with the workshop input.
 

ZWH rebmem

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agree. keep it as a last resort.

if nothing wrong dont change it..

Do those small preventive maintenance first.

Older cars fc tend to drop abit.
 

snipfer

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yesterday car fuel gauge showed about 10% left... went to petrol station to pump full tank, but only managed to pump 28l ... some how the fuel gauge is not accuracy..

This one you need to send for a check

Sent from Xiaomi MI MAX 2 using GAGT
 

Z_Dash

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Added oil addictive.. looking good.. will update the fc..lol

Avoid adding too much.

Once I was quite into addictive till somehow my fuel injector kinda affected and I keep getting error code "fuel too lean".......troubleshoot damn long till I replace fuel injector and problem solved.
 

Kula Diamond

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Engine overhaul usually is engine uplorry or do modifications de la

Overhaul for FC is madness
 

wira

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Why would anyone wants to do engine overhaul just to improve FC ?

Just like someone going to do massive open heart surgery just to make sure heart can beat stronger ?????
 

hoboonhua

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Avoid adding too much.

Once I was quite into addictive till somehow my fuel injector kinda affected and I keep getting error code "fuel too lean".......troubleshoot damn long till I replace fuel injector and problem solved.

dont know that... bro how much did you pay to replace fuel injector?
 

logitech123

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Avoid adding too much.

Once I was quite into addictive till somehow my fuel injector kinda affected and I keep getting error code "fuel too lean".......troubleshoot damn long till I replace fuel injector and problem solved.

usually adding too much addictive will confuse the O2 sensor. after driving awhile it should be back to normal if not reset to ECU to let it relearn to calibrate the MAF
 

Z_Dash

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usually adding too much addictive will confuse the O2 sensor. after driving awhile it should be back to normal if not reset to ECU to let it relearn to calibrate the MAF

Quite sure it's not confused ECU as I reset probably like 30 times in attempt to troubleshoot. Every workaround I tried will reset ecu and the error code will appear within half day.
 

BuGGi3

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Old sienta same engine as VIOS.
go check out what those vios owners do.

Vios here. Also 42L tank, 450km per tank is decent for Sienta is heavier. What FC do you want to achieve?

Any other routine maintenance not done yet? ATF change? Any engine oil leakage? Brakes working fine and no screeching sound? Wheels well aligned? Spark plugs changed?

Try cleaning MAF and throttle body - not those $50 carousell ones which dumps chemical into your air intake, but those that really remove the tb to clean off the carbon. Can consider changing ignition coils, fuel filter & pump worse case.

Are you using stock rims?
 
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