Dear ts, u prolong to 20k for oil change really messed up your engine. Whether the damage is already too much or not we do not know unless we test it.

If u dont want to spend any more money on it..u can put a bandage... Everytime pour in lucas oil stabilizer into your engine during new oil change.

Follow below steps if u want to save money + help your engine.
1. Go mechanic and do dry compression test for all your cylinders are good. If still good, proceed to step 2. If no good, u will have to do full engine overhaul because your cylinder walls already almost certain full of deep scratches and grooves. Full overhaul for damage like this includes rebore cylinder walls and putting in bigger newer pistons. Rm5k and above easily.

2. Take boroscope and look down into cylinder walls. If no deep scratchs on cylinder walls, proceed step 3

3. Buy engine flush or cleaners like marvel mystery oil, lucas complete engine treatment, etc. It is a aggresive cleaner. Follow the instructions. Not 100% but hopefully this will slowly clear the gunk around your pistons and free up all your rings and also oil passages that has been blocked. If oil consumption reduced, u can try again. If no reduce, go step 4.

4. Open up and pour marvel mystery oil directly into pistons through spark plug passage way. Wait few hours, manually turn the engine a bit, then pour again and wait another few hours. This way is very very aggresive in case step 3 does not work. See youtube to get what im saying or find a mechanic to help you.

... you mean sometimes 20k KM only change engine oil?

thanks for all those tips!
sometimes i do service very late but my honda city which is older and with the same practise does not has this problem

sometimes i do service very late but my honda city which is older and with the same practise does not has this problem

I am using Bardahl FS engine oil 5w/40 and along the way, the engine oil star decreasing, almost more than half of the dip stick mark.
Foreman say that the oil might not be suitable and I have to use 10w/40 instead.  Any comment?

I'd been changing engine oil between 16-21k km (fully synthetic) intervals for like 5-7 years in a 2007 toyota odo 340k km.

Before that was 7-12k km for semi-synthetic and 6-9k km with minerals like 15W40 or 20W50 since around 2010.

Till todate I have no engine oil consumption problem.

However I do have engine oil leaking problems like valve cover gasket leaks (rectified) and at the moment, front oil seal/timing cover leaks of about 200mL over 12k km usage which remains unrectified (Note: no dripping drops on overnight parking).

Have a read on 'Italian Tune Up' for stucked/clogged piston ring related oil consumption problem.

Thats interesting. May i know what kind of roads u usually drive? Everyday taking the highway? And how long before reach 16k km? Which engine oil you used and what additives you added, if any?

Using federal highway to work at KL Sentral and returning to Subang Jaya thru NPE, plus S Jaya internal roads etc.

22-24k km per year before covid, 18-19k km per year during covid 2020 2021...

Fully synthetic Shell Ultra 5W40 and currently Mobil 0W40.

Semi was Total Quartz 7000 Energy 10W40.

Mineral was Shell/Petronas 15W40 and 20W50.

Post #1 Blotter Spot Test

bobistheoilguy

to check whether there is a engine oil consuming problem, can i just ask foreman to check on the piston

You should read TS's practice. He can prolong the service beyond 10,000km and up to 20,000km.

You might escape it doing it once or twice, but if you constantly does that, engine problem will come later. That is, for cars beyond 8 years old.

I'm one of them, but instead of prolong mileage, prolong interval 
Guilty.
My last oil change was dated 20 August 2020 and I just did an oil change on 17 August 2022.
Exactly 2 years with oil change interval mileage of 9800KM.
This is on my 8 year old Exora Turbo.

Car is only used either long distance drive or sometimes short distance.
And me also do not recommend following my steps either.
Luckily turbocharger is still fine, still able to sprint hard on the highway.
No engine oil consumption throughout the interval.

The practice is risky though one might get away with it through usage of high quality fully synthetic oil..

Found this video whereby a BMW m3 has been sitting for 4 years and 7 years without oil change?
Its a FB reel video thoigh.

https://www.facebook.com/reel/1032720754094...a2HwwtJopec72Vb

I hope the BMW engine is fine. Tried to find the full video on his YT channel - ShoLifeTv can't find the full video.
I won't recommend putting that long.

I am using Bardahl FS engine oil 5w/40 and along the way, the engine oil star decreasing, almost more than half of the dip stick mark.
Foreman say that the oil might not be suitable and I have to use 10w/40 instead.  Any comment?

my current situation: 16 years old with 250k+ km and 13 years old with 440k+ km. both on 5w30 full syn, both engine is never done any overhaul before, both engine rev to before rev cut says few times in a week at least, oil consumption based on top up around on 5k km is between 0.5~1L.

my suggestions: check engine inside out and/or change foreman.