Have Noisy Valve
(The below, assumes you know it really i,s the lifters making noise , use your $5 mechanics stethoscope, to be sure)
The problem can be simple or complex. It can be 2 problems, KEEP AN OPEN MIND!
Start with easy and work up. I will list all the noise makers. (try)
Both type of lifter (Adjustable or Hydraulic) (1.8L and bigger motors have HLVA)
Staking is what we did for hundreds of years, (mechanics) before the advent of , LOCTITE. (in this case it is only the countersunk, flat head screws, seen on 8v)
Staking simply, upsets the metal surrounding said screw. Jamming it.
Adjustable Valve Lifers:
Running 0 (zero) weight viscosity oil ? in the hot summer? will make lots of valve noise. and this oil is not listed in your FSM nor is it listed in your operators guide.
So, pray tell, why are you running illegal oil, in the crank case. ? (trying to save fuel ,at the expense of a blown engine?)
The Valve lash is excessive, set it per the manual.
The worst case:
In the military we called this "messing (stronger words) up a soup sandwich." He buddy , your mech could "Frak up a soup sandwitch"
You? let the TIMING belt slip (60,000 service , was/ is not a thing for you?)
Then you or Mr. Soup, try to set lash and get confused about 4 cycles, and TDC and all that bother. ?
Then manage (horror) to get the valves lash so wrong, as to have 1 valve, say , #1 exhaust last so wrong, and was set ,so it never closes, in a gross manor?
The #1 piston, when hot this day, and at high speed , hits the valve and bends it. Kiss off #1. Here is Mr, Soup doing a bundle.
I think both engines, are free-running, dispite SUZUKI, quoted warnings below, but if you work hard, at that soup sandwich, bad can happen. (Takes hard work)
T-belt slipped, valves noisy or smacking your piston tops
Hydraulic: HVLA (Hydraulic.Valve Lash Adjusters)
As found on 1.8L 1996 Suzuki Sports or newer and or bigger Suzuki engines.
They fail for 3 reasons.
Change oil at 3k to 7k miles, the higher mileage engine gets more often change outs.
This also keeps the Cam CHAIN from , going bad , early
If the HVLA is gummed up, take them out and clean them with GUNK/ or berrymens cleaner or soak them for 24hrs, in pure ACETONE and then clean them.
They will (HVLA) need to be primed after cleaning, Read the FSM or go to alldata.com and read the on line FSM. Its all there, and costs only $15 for 30day look.
The FSM is here, just LOOK. DIY , no need to be in the dark, lit $15 bucks set you free.
ALLDATA DIY Access - 1 Month