Essex

Hi, I have an '06 Rio5 automatic hatch which has the same motor as the new
Accent (1.6 Alpha CVVT).

It has always had some piston noise when cold and I realise that's quite
normal but just recently I've noticed a piston noise (sounds like just 1
cylinder) even when hot.

This occurs at around 1700rpm under light load e.g. coming up a long,
slightly inclined driveway at about 15kmh. It's not pinging as I use
95RON.

I always drive the car with consideration and ran it in carefully. It's
due for its second oil change (15000ks) and I supply my own oil to the
dealer (Castrol Magnatec).

Is this condition more than just an irritation? Could it cause premature
engine problems? (out of warranty of course!).

Should I push this issue with the dealer before my warranty runs out?

Do you think a different type of oil may lessen the problem?

Like everyone else here, I appreciate your presence on these forums.

Thanks, Rick

hyundaitech

I don't believe this is a piston slap issue. Piston slap typically occurs
independent of engine load. Of course, if that's the case, the cause of
the noise is still unknown.

I'm also not sure whether you should rule out spark knock. In the U.S.,
we don't use RON, but an average of RON and MON (motor octane number).
Here, the recommended minimum octane is 87. A quick google search leads
me to information that suggests that our octane numbers are about four to
five less than the RON. All things being equal, that would put you in a
good position to make the knock statement you have, but I don't know the
minimum octane rating for your country. If you're above the
recommendation in your owner's manual by four or more, then you're
probably correct that it's not spark knock.

Absolutely ask the dealer to look into this. Give them detail about the
conditions under which it occurs, so they can reproduce it. Without
knowing what you're hearing, it's possible it's normal, but it's also
possible there's a major problem.

As long as your motor oil meets the minimum specifications in your owner's
manual, changing motor oils is not likely to affect the noise. Consumer
Reports did a test on motor oils and determined that nearly all name brand
oils provided excellent lubrication and protection.

Essex

Thanks Hyundaitech, it looks like it's time to don some armour, take a deep
breath and go into battle with the dealer.

In Australia, to most dealers, anything short of a con-rod through the
side of the block will always be called "normal"!

Thanks again, Rick