Engine rattling from cylinder head/ oil change

bliu6757 · Postby **bliu6757** » Mon Dec 10, 2018 10:37 am

Car: 2006 NC manual 6 speed

Did an oil change yesterday with penrite HPR 5w40 (5L) and ryco oil filter z632.

I know the recommended is 4.2-4.5L, however, I put all 5L after draining the oil completely.

Now I have a rattle sound from the engine (sounds like it’s from the top, maybe cylinder head). You can hear the sound slightly on idle and more noticeably when the car is in gear (3000-5000rpm is peak sound).

Any ideas? Is it an overfilling issue? Is it even an issue related to the oil or something completely different?

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RS2000 · Postby **RS2000** » Mon Dec 10, 2018 12:09 pm

Does the manual say 4.3L including filter? If so, that 700ml extra, which may mean the crank is running thru' the oil, which can cause aeration. Let out half a litre & see if the sound is different.

hks_kansei · Postby **hks_kansei** » Mon Dec 10, 2018 12:53 pm

As above.

Too little oil, stuff doesnt get enough oil and clangs together.

Too much and the crank whips it into a foam, which means it doesnt form a protective film, and stuff clangs together.

I assume the level shows ok on the dipstick?

bliu6757 · Postby **bliu6757** » Tue Dec 11, 2018 10:59 pm

Done! I’ve taking out the excess oil.

However, the sound is still there. Is this the commonly known nc1 engine failure I dread??

Anything that can be done at the moment??

Help???????!

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hks_kansei · Postby **hks_kansei** » Wed Dec 12, 2018 10:09 am

I think the only real diagnosis is to find exactly where the sound is from, and then start visually inspecting stuff.

You can use a screwdriver against your ear as a primitive stethoscope to help find specific locations for the noise.

Then yeah, look for obvious things like something caught in a pulley etc, then move onto bigger things like removing parts to inspect.

Mr Morlock · Postby **Mr Morlock** » Sun Dec 16, 2018 7:53 pm

I would get someone who knows the engine to take a listen but even using a stethoscope is much harder to id something than you think- i.e. a noise is what? Are you really sure its noisier after having changed the oil. If you talk to a good dealer Mazda trained mechanic they may well diagnose it quickly or give you some advice- not necessarily at much cost.