Technical Old grande Punto making tapping noise in hot weather

[Priyacha]

I've a 2007 grande Punto petrol, 60k mileage. Two years back, immediately after getting a full service, my car started making a strange noise when accelerating. Noise used to disappear at higher speeds and get considerably worse in hot weather.
I spoke with other garages and suspected it had something to do with the oil change, new oil was probably too thin? We got the new engine oil drained out (shell 5w30) and replaced by 5w40 Granville fully synthetic. The manual said 5w40, so made sense to try. The noise immediately reduced by 90% but still stayed unfortunately.
A year later I got my cambelt and water pump changed and the noise disappeared fully. Didn't get the noise for the next 10 months at all.
Last week it has come back again unfortunately. It gets worse in hot weather, or after I've been driving for a while.
I'm wondering if I should try a different oil this time or is this being caused by something different (e.g. why would cambelt change fix the issue and why would it happen again after 10 months)? The car makes only 2k mileage per year so don't think it needs another cambelt change. Any thoughts will be much appreciated.

 

[oldmanhouse]

How long since the oil was last changed, presumably at least 10 months by now? Did they also change the oil filter? Probably worth doing both regardless if it's been >6 months.

Which engine does your car have? 5w40 is correct but also make sure the oil meets the Fiat spec 9.55535-S2, it will list it on the bottle

also keep an eye on your oil level, check it's not gotten too low

 

[Priyacha]

Thanks, yes last oil and filter change was 12 months back. As soon as the noise came back, I topped up the engine oil to ensure its at correct level but that didn't help. I guess full oil and filter change is the next step? Should I go a bit thicker than 5w40 this time or might it harm the engine?

 

[eeeno]

The valve clearances could need adjustment if it's manual adjustment like normal 1.4 8V have.

 

[GrandePunto PL]

Word "petrol" doesn't help. Which one (engine) exactly?
Also "tapping" (or "ticking/clicking") is not precise term. It could be many things...
- Valves, clearances (both hydraulic or manually adjusted with shims).
- VVT wheel (pulley itself or solenoid valve screen filter is dirty). Timing belt job can move/disturb something inside, in a good or bad way.
- Lubrication system issue (which affects the VVT).
- Exhaust leak (broken manifold studs, pretty common in FIRE family), yes it can "tap tap".
- Clutch is failing slowly (especially release bearing). Gearbox/axles, I doubt it.
- Something else (some "play" in the cam or crankshaft, something's going on with the piston rings) in the engine ("knocking"?).
Or it's not the engine. For example, temperature dependent, exhaust + suspension problem and/or clutch?

Low annual mileage is very bad for the whole car (body, suspension, engine etc.). This is "car abuse". Asking for trouble.
First advice is: drive it more (and no short trips). Second: no "long-life" (oil changes). And stick to the 5W/40 (no stupid experiments like pouring "thicker" one). Consider engine flush during next oil change - if it was never done before (if it was, then the opposite, don't flush).

PS
Come on, it's 2022, you can (you should) record this sound, noise (both from inside & outside the car). Maybe then we can guess better.
Additional question: what you will do about it? Will you personally repair anything, or you are just curious (and the car will go the professional workshop anyway)?