Hello, I have a 1992 mitsu strada RHD from japan. comes with the 4d56T setup. 150,000 kms
Lately I've been trying to find/determine where my power loss(10-20%) is coming from. I have to drop a gear to climb hills now that over a year ago i wouldn't.

I do have blow-by, enough that when the engine is idling and i remove the dipstick, it will spray the engine bay.

I do the usual maintenance oil/fuel/air filter.
re-re injector nozzles, shop said IP was good at time of injector re-re
fluids all around are good

Here's my last weekends fun
reset valves: they were bang on from last year except for cyl4, .002in high
done warm, set to .010in

compression test (440 is a brand new engine)
done warm
cyl1 425
cyl2 415
cyl3 405
cyl4 435

leakdown test
done last(~ 2 hours after shutdown, was in a heated garage though), so still a warm block
cyl1 10% no noise, couldn't really tell where any air was coming from
cyl2 18% noise, air leakage from crankcase (dipstick tube)
cyl3 18% noise, air leakage from crankcase (dipstick tube), and from intake (a tiny bit)
cyl4 9% noise, it was coming from the crankcase.


looking for a little insight. what are the upper most limits to the leakage rate?
does anyone have results from their engine?
Am I due for new rings?
any others comments?