I HAVE A 1999 CIVIC WITH A 1.6L ENGINE.IT HAS A TICKING NOISE LIKE THE LIFTERS TICKING,IS THERE A ADJUSTMENT ON THESE LIFTERS

could possibly be a lifter tapping (Ticking) ,depending on how many miles the vehicle has on it might be time for lifters to be adjusted,most foreign overhead cam engines must have lifters adjuster periodically ,if you turn on the air its puts more of a load on the engine causing a louder sound (also check oil level an engine low on oil will start to tick too.. the more wear the engine gets the looser the lifters can get over time ,look in your service manual if you have one and see what the intervals are on lifter adjustment this can give you an idea.
possible only if
the ticking sound is coming from the top of the engine usually comes from under the vavle covers where the lifters are located,

ticking noise from an engine is more than likely the rockers under the valve cover. after a long period of time, the lifters and the push rods wear and cause fatigue in the metal and also the lifters can also start sticking from ling usage and dry oil getting stuck inside them

ok the ticking noise is your lifters and you try and use a thicker weight oil in it it should go away

Ticking noise is usually the lifters in the engine.

This is a sign of an aging vehicle, but not to worry, it can be helped if not cured completely. Normally this is caused by sticking lifters from carbon buildup in your oil. First check the level of your oil, make sure you havnt been running on half capacity. Then I would recommend going to the auto parts store and purchasing an oil additive like sea-foam or one that says it helps with sticky lifters and engine knock. Add this to your oil in the appropriate amount. Drive for a couple hundred miles or until the noise gets better. After that, change your oil, and dont use the additive with the new oil. this should last for quite a while, but with an aging car, you may have to do this once or twice a year, or perhaps every time just before you change your oil.

Did you check your oil level? Is the oil light on? (No oil pressure) try changing oil & install an engine additive for noisey lifters, If none of this works need to place lifters

The valves never need adjusted, .Do to hydraulic lifters and zero clearance.The rocker arms are torqued to 35 ftlbs.So you never have to worry about it.If there is a noise have your lifters checked:)

My guess would be a sticking valve lifter. Buy a can of Gunk Motor Flush ( NOT radiator flush), use as directed, drain the oil and replace the filter, refill with clean oil, and see is the tick has gone away. Marvel Mystery Oil would work also if you can't find the Gunk.

You might have a bad hydraulic valve lifter (assuming this engine has them)... you could try an aftermarket product designed to unstick valve lifters.... any auto parts store carries them.

Sometimes the fuel injectors make noise simular to lifters