Toyota Ceres

[DUMINDU]

hi,

i own a ceres (yom93) which maintained well. use 90 octane fuel with regular services. used to ride this for almost a year with no hassles. recently got a ignition knock while going thru 3rd 4th and 5th gears. and the oil level is geting down between 2 services about 3/4(which i think, has been when i bought). i use SAE 40 oil. odo186k. pls advise me for getting rid of these problems. im a daily ranner(60km/day)

thanks.

[The Don]

hi,

i own a ceres (yom93) which maintained well. use 90 octane fuel with regular services. used to ride this for almost a year with no hassles. recently got a ignition knock while going thru 3rd 4th and 5th gears. and the oil level is geting down between 2 services about 3/4(which i think, has been when i bought). i use SAE 40 oil. odo186k. pls advise me for getting rid of these problems. im a daily ranner(60km/day)

thanks.

Well the key seems to be uncovering what is causing the loss of oil. Since it seems to have coincided with loss of power I fear the engine might have started to burn oil. If there is no obvious oil leak get a compression test done.

[DUMINDU]

thanks don.

ya there's no obvious leak. i'll do the test then. can you pls tell me wht is causing the knock and how to get rid of it. thanks again.

[varunatech]

thanks don.

ya there's no obvious leak. i'll do the test then. can you pls tell me wht is causing the knock and how to get rid of it. thanks again.

Can you be more elaborate on the knock, I have a feeling it is a Preignition knock as a result of chamber deposits. But please be specific and thorough when describing.

[DUMINDU]

thanks varunatech,

early in the morning when i start it does not appear but only after 5, 6km(?after the engine heated enough). it doesnt come all the time, but when the load is high. but when i give a bit gas more the "krrrr krrrr" sound fades. once used a 95 octane fuel where the knock seemed dissappeared and appeared again when using 90 octane. that's how i can explain it. pls help me elaborate. thanks

[varunatech]

thanks varunatech,

early in the morning when i start it does not appear but only after 5, 6km(?after the engine heated enough). it doesnt come all the time, but when the load is high. but when i give a bit gas more the "krrrr krrrr" sound fades. once used a 95 octane fuel where the knock seemed dissappeared and appeared again when using 90 octane. that's how i can explain it. pls help me elaborate. thanks

From what you have described, what I can identify is a Pre ignition knock. Mind you just from what you have stated here, without seeing your car.

This is sometimes called engine pinging too.

Heated engine, under load, and fades away when gas applied, diminish when you pump Octane 95 are telltale signs of Pre ignition knock. When this is a slight issue, nothing to worry, there are thousands of cars out there with engine ping, even the owners never notice it.

However, it is always advisable to correct the situation as Pre ignition knock may lead to harm your engine. And it has harmed engines many times as well.

A simple way to get rid of the carbon and other deposits is to.......

1. Use a fuel additive (effective with right product............BG44K, WURTH, Abro, 3M to name a few)

2. Do an Air system intake cleaning (Very effective..................BG Air system clean up, 3M and WURTH has something similar)

3. Do an engine clean up (Corrects the issue and also help you to get rid of other issues...........but expensive and can be last resort......... probably never done unless Pre ignition knock, becomes unavoidable large detonations).

I have corrected the same issue in many cars using additives and Air system intake cleaning. I do personally prefer BG products, still there are other good products too. You can search my posts where I have given step by step instructions to someone else. Or you can ask again........

I am not familiar with your car, I will look for the engine type. Usually YOM 93 cars can take Octane 90. What I feel is your car has got carbon and other deposits over a long time and now does Pre ignition. Octane 95 helps as it delays the ignition. If this is the case an Air system intake cleaning is the best, or you can just throw a can of Fuel system cleaner at the tank and see, no harm done, only good is done.

By the way before adding an additive to the tank, can you remember when is the last time you changed the Fuel filter.

[varunatech]

Hi I did have a look at your car and engine spec. If not mistaken you run a classic 5A-FE engine. Did look for the Octane rating stated by the manufacturer, (actually from the joint manufacturer in China), it sates RON 93 or above while conforming to some emission standards. Your engine will run on 90 Octane as it has done. But the engine design has been for RON 93 and above. This is actually the sane for many engines we use here. All other engines we have here 121, Vios, Allion, Yaris, Belta etc.... all are designed for RON 91/93 or above. In SL we have RON 90 and RON 95. The latter is far more expensive. And people just pump Octane 90.

Your problem root cause is not only Octane 90, it is only part of it. Any engine after 15K, 20K kms builds up chamber deposits. Time to time clean up is required. You hear engine knock and Pre ignition, when these deposits become sizable and when they get red hot.