grinding sound when car is cool and doing engine brake

[jkyamog]

Hi,

My 14 year old mini truck (Feroza) is making a grinding sound whenever its cool. More apparent ito pag mornings. So when I release the gas pedal and cause an engine brake it makes a grinding sound. About 1-2km the sound disappears. The longer the car rests the louder the sound when it travels, this only appeard on its 14 year history this rainy season. The car was not flooded recently, I am puzzled what could cause this.

It does NOT make it during braking, when drivetrain is disenganged (Neutral or pressing the clutch), or turning.

I am thinking that the rear brakes are dusty, the 120w gear oil is causing it (but it has been there for 2 years na). What do you guys think of the other possible causes?

[g-shock]

kung tinagalog mo nalang baka sakali naintindihan namin ang problema,repraise your sentences and make it simple . PEACE

[nugundam93]

off-hand, it seems grinding gears since you did say this happens when doing an engine brake. have the gear oil replaced muna and see if it goes away or lessens. i think if it lessens, sa gears nga.

that's what i think anyway, let's wait for the gurus here :D

[gwapito69]

baka nga gear grinding. check mo yung fluid baka wala na o hindi na ok.

[jkyamog]

I still have an extra liter of Mobil LSA 90. I think I need 1.5 liter for the diff. Anyone wants to trade with 2 liters GL-5 90w for the 1 liter Mobil LSA 90?

[speedyfix]

is the grinding comming from the tranny or from the engine?

[jkyamog]

speedfix, the sound is coming more from underneath the car.

[gel_salazar07]

speedfix, the sound is coming more from underneath the car.

Maybe its your transmission? Better yet have it check for the gear oil and gearing play?

[speedyfix]

yeah baka may sayad or something.

[jkyamog]

I replaced the diff oil with my extra Mobil LSA 90 1 liter + .5 liter of GL-5 90 oil. It improved buy grinding sound is still present.

[speedyfix]

is the lsa90 compatible with the regular gl5 gear oil? parang alam ko hindi.

[jkyamog]

I am not exactly sure about their compatibility. I couldn't find another liter of lsa90 on nearby shops, my extra liter was the excess liter I bought for my terrano that I sold recently.

My assumption is that gl-5 gear oil with lsd additive can be used as substitute, so I just adding .5 liter of gl-5 oil is ok since the diff needed 1.5 liter. The assumption does not have any scientific basis just guess work, since I needed to decide if I use 1 liter oil or 1.5 liter of mixed oil.

I just wish I wasn't too kind to give my extra .5 liter of lsa90 to the new owner of the terrano as his sample.

Thanks speedfix for the advises. I will observe and change the oil when I am able to buy 2 liters of lsa90 again.

[OTEP]

On some vehicles [e.g. early MB100s], the noise is considered normal [although they did make running changes to the transmission to quell it during the later years.

Try mo muna mag-change ng transmission oil.

[jkyamog]

Thanks OTEP, changed the oil about 2 years ago. I checked it and it was still full. This grinding sound only happened recently in the 14 years we had the car.

[speedyfix]

pare, kindly check with your mobil 1 technician or write to mobil to ask if they are compatible. this may cause you more damage and problems in the future if you let it go unchecked.

i don't have any scientific reason to think so, or experience with mixing the 2 on your car so i really can't be sure.

pero normally when you put regular oil on a lsd equipped vehicle you will tend to burn the lsd and it could cause seizure in the future.

[OTEP]

You could try adding LSD-additive if bago pa naman and puno pa ng conventional gear oil. Sa mga gas stations and sa mga Ace/True Value meron naman nun.

[jkyamog]

The oil on the diff is 1 liter lsa90 - which I believe what is used for lsd. .5 liter is gl-5 oil only. So granted that the mobil and this other oil will mix, I have like .5 liter of oil that does need to be have LSD additive. Its the .5 oil that is not lsd compliant. I will relook at ace when I have time, kasi unfortunately true value did not have it as of this time. Gas stations nearby actually offered much poorer advice, use their gear oil for the diff! (which I believe is gl-4, although they don't know that... they say they use for all kinds of things)

I am still trying to see if the problem is diff based. After a few days when I have time to buy the proper oil, I will likely drain again. The car is used by my wife for about 2km per day, so I guess no major damage will occur until I find 2 liters of lsd oil or lsd additive.

[jkyamog]

Ok it seems to be a diff oil issue, the cold weather and low usage may have made the oil viscousity too thick. My wife told me today that the sound is gone. I just need to buy 2 liters of lsd oil or add 1/3 additive. Thanks very much.