hey guys

my a15 is making a strange knocking noise that seems to be coming from the valve train. i cant worked out what it is, i have reset the tappets and everything is tight so i am stumped. it only starts to happen when the engine is warmed up.

any suggestions would be appreciated

Grab a long screw driver and place it on the top of the engine whilst ideling and put the handle up against your ear,move it around till you can hear clearly what the noise might be,works like a stethascope and report back

By "tight" what do you mean? You have set the valve clearances right......

yer well the tappet clearences i set to my cam specs which predicate 15thou. I have also made sure the rocker studs are all tight. I am wondering if it is a timing issue or a valve is damaged, im just not sure.

I think I have the same issue. The knocking only comes on when the engine is warm and even then, it is irregular. Coming on one minute and off the next, I haven't checked the tappets yet so I think thats my problem. It's not a very deep or hollow knocking, but it's enough to get you worried.

Mine does the same.It is a knocking sound but not loud. And also only when engine is hot.Can it be the oil being too thin when hot?

I even listened underneath the car to hear if it is not louder indicating bearing problems on the crank or conrods.It is actually softer underneath the car and louder at the cylinder head.In my case cannot be piston slap,bearings in engine or play at the small end of the conrods.We checked it when engine was overhauled 50 to 60 000km ago.Was no slap and bearing caps were replaced with new ones.Cylinder head completely overhauled.
I am just living with it.

reviving an old thread here lol anyone else havin these problems as mine has just started doing this as well... A15 all stock just adjusted tappet clearance and noise is irregular. comes on when driving and slightly moving the accelerator pedal can make it stop??? wtf

IF it is a tapping sound more than a knocking sound, set the valves. Even 2-thousands off will be noisy.

15 thousands inch with a stock cam will tick.

They should be set to .014" HOT or .013" cold at the maximum lash (can be set tighter: .010" cold is used by many). Use the next size up feeler gauge to ensure it WON'T fit, or your may get noisy valves.

ok will do it again tomorrow but i set them to .012" hot, dont think its the tappets. its not the normal tappet noise, more of a deeper internal sound like a chain sound hard to explain without actually listening to...

To check the timing chain, remove the distributor cap, and turn the engine by hand clockwise. Then check the rotor position. Finally turn it back anti-clockwise until the rotor moves. How much did the engine turn before the rotor did?