What should the engine sound like?

[MrPolite]

I don't mean "vroom vroom" (before someone says it...

Mine has done 81000 miles, and sounds quite "busy" - discernable tappet noise and general operating lash. I also get a quick clatter when started from cold for a second or two.

It seems to me to have got worse over the past month I've had it, especially after a good run - today it did 140 motorway miles.

 I'm wondering if it doesn't like the oil I used for it's recent change, which was eurocarparts QX 5/30 fully synthetic.

Or are they a cliketty sounding engine at higher miles?

Clearly it has been neglected before I got it, and such damage can't be undone with an oil change.

But I'm wondering if a thicker oil would help, or are they all like that?

[Jocko]

You get "High Mileage Oil" which isn't thicker but is designed for high-mileage engines, which both Castrol and Valvoline reckon is above about 70K miles. I was advised, via my son-in-law mechanic, by an oil engineer, to use a grade up in my 120K mile Volvo.
My Jazz was not noisy at 100K+ (DSi engine) but I found if I topped up with 10W-40 (which I had in the garage) instead of 5W-30, it ran even quieter.

[TnTkr]

With such low mileage there should not be almost any wear in Honda's engine. Thus, when there is increasing noise, I would consider valve adjustment.

[madasafish]

With such low mileage there should not be almost any wear in Honda's engine. Thus, when there is increasing noise, I would consider valve adjustment.

Agreed.
I  would also suggest using a HONDA oil filter only . Some makes are prone to oil drain  when stationary  - engine rattle on start up due to momentary lack of oil pressure

[fatal]

 I would suspect some valve gaps may have opened up.

[Lord Voltermore]

Unless you are 100% sure the correct, top quality, oil filter was used at the last oil change it may be worth changing it as a precaution.  Some  budget filters have poor filtration materials,  and sometimes ,even with a top quality brand, the wrong model of filter has been used which might appear to fit  but does   not for instance incorporate a  built in  oil by pass valve  etc that might be required.   

I also find if you begin concentrating on a particular  noise   concern it always seems to get worse. 

If you suspect that oil changes have been neglected for a long time  its a good idea  change the oil as well  sooner rather than later. Dont wait for the next service to fall due.    Renewing the oil early may help clear away any contamination that may have been dislodged from  oil passages etc.    .

In 'the old days'  they sometimes used 'flushing oil' to do this  but its not something thats normally done these days.   The danger is it can dislodge long established   crud that has accumulated somewhere harmless allowing  badly contaminated and abrasive oil to circulate to more  critical areas and possibly cause further blockages.     

[Jocko]

I once drove from Fife to Aberdeen in a car and it sounded like the big ends were starting to go and I was considering turning back (which I didn't). And sure enough, 50,000 miles later I crashed into the front of a lorry! You can get fixated on a sound which is perfectly natural for the car.