startup engine rattle till oil pressure rises

[Willieo]

I was worried about this on my new 350z and had taken to jagging the starter a couple of times so that it turned but didnt fire up to prime the oil system because I could hear rattles until the oil pressure came up. I know it is literally less than a second but this is when you get wear. I thought most likely a crap or faulty oil filter allowing drain back overnight or rubbish oil. So replace the oil with full synthetic and a new KN oil filter ( arent the oil filters titchy on these?)

 

Result no rattle this morning just the right sound when it lights up and jumps straight to 2000rpm! before settling back.

 

These engines do fire up instantly and do seem to rev quite high just when lub oil pressure could be slow to build.

[Beavis]

Mine has always rattled for about a second on start up most of the time, even with oil like wine and a reguarly changed filter. I never worry about it.

[Ken]

Mine has always rattled for about a second on start up most of the time, even with oil like wine and a reguarly changed filter. I never worry about it.

 

Mine is the same.

[Zugara]

try some molyslip, it may help.

[HassanZ]

Mine rattles just as I fire her up too. Lasts for about a second...I was worried it may be something abnormal too!

 

It rattles for about a second when I switch it off too....

[lrh]

Engine with timing chains tensioned by oil pressure can rattle for a second while the guide takes up the slack. Nothing to worry about.