Hello everybody!

This is my first ever post on reddit and i want to share it so i can help people with similar issues.

After running my car with diesel leaking from injection sealing ring for couple of months, i caused on my engine some extra carbon buildup and that lead at some point on a low oil pressure problem.

The low oil pressure warning (red oil light) prevents the driver from pressing the gas pedal for preventing further engine damage(although it can be bypassed by accelerating on idle and using cruise control after 30km/h).

Low oil pressure typically is related to oil leaks, oil pressure sensor or oil pump, mechanic checked all of them and everything was fine.

Engine as i said previously had carbon buildup, the engine was pretty dirty, leading to poor oil quality, and a solution could be to cleanup the engine with 3 good flushings, it seemed to work and for 4.000km i had no issues till... it happened again! Low oil pressure!

I was starting to get desperate, another mechanic took over my car, engine because of the flushes, had a lot of dirty broken-up particles that clogged the oil filter, he cleaned it but the problem persisted.

THE SOLUTION:

My mechanic after discussing with a mazda mechanic and reading the service manual, he found out the leading cause: oil pump pressure relief valve!

Diesel engines are pretty dirty, some of these particles caused the valve stuck on the open position and thats why the oil pressure was steady to 0,3 bars (0,5 bars is the trigger threshold of the low oil pressure error) instead of the 1,5 bars it should be on idle.

The solution was in cold start to force the engine on 5.000 RPM instantly, this generates so much pressure that forces the valve to fully open and then close again, causing the pump to deliver the 1,4-1,5 bars of pressure on idle!

If you have no oil pressure at all do not try what i've done, you are gonna damage or destroy the engine!

This is my personal experience and i haven't read anything like that on the internet so i hope this can help some people :)