Elantra 2012 1.8L "NU" engine tap/knock

[Damon Rigby]

Hi All

I have signed up for some advice. I have a 2012 i30 (AKA Elantra) with a 1.8L petrol ‘nu’ engine. Over 200,000 kms so very high mileage

Developed a tapping sound, seems to be coming from top/middle. Thought it might be lifters/rockers.

Changed oil twice in last month.
Tried a thicker oil 20w50 with no luck then swapped back to 5w30 full synthetic
Thought it was lifter noise so Installed 16 brand new lash adjusters and cleaned and freed up rollers on rocker arms . General running smoothed out but tapping noise did not.
Added Liqui Molly friction reducer and Liqui molly tappet noise reducer
10 seconds of sound is here;

[MEDIA=soundcloud]damon-rigby-780323580/20200212-194616a[/MEDIA]

The tapping sound seems to be 1100 or so taps per minute at idle (at around 700 rpm or so). Tapping correlates to rpm’s

Given piston goes up twice and down twice per revolution then maybe a sound of piston on up or down stroke? not sure. Piston slap? maybe crankshaft?

Also I’m using original oem oil filter; no check engine light and no obd scanning codes showing.

Any ideas?

Cheers!

Topic

[Richard Kirshy]

Might suggest trying Marvel Mystery Oil added to the crank case according to the directions and see if that helps.

[Author]

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