Just thought I'd share my findings on a recent jobCar came in with a bad knock and no power.
fitted four new injectors and still had a knock
Took off the intake manifold to be greeted with this

Some of the ports are completely blocked right back to the valve stems and the runners are over two inches deep.
Might help someone with similar symptoms on a job.

 

What year/engine and how many miles were on the car?

 

Not sure on engine code but it's a 2015 2.2 diesel with 125,000 km

 

SH engine code.

That is the worst I've ever seen, and I've seen tons of them thru my dealership.

If you still have it apart, I strongly recommend replacing the plastic water pipe/junction in the bottom RH corner of your photo.

 

It's back together unfortunately customer couldn't afford to have the head pulled off
But I would say it needs cams and vavles it's pretty much ****ed at this point.
Never seen something that bad before and I'm doing this a good few years lol.
Local main dealers has a walnut blaster for cleaning the head so it's obviously a common issue

 

Kia/Hyundai solved this problem by adding an extra injector just to wash the intake valves with the main injection happening directly into the cylinder. Wonder if Mazda is taking notes.

 

That is the worst I have ever seen either....wow and I have seen maybe hundreds..... you win first prize!! FOR SURE!!

 

Toyota used a dual injector system as well.
Wonder the cause. PCV system?

 

Looking at the complete picture of everything not just the obvious, I would say POOR Maintaining and keeping up with scheduled and routine servicing?

 

Which diesel Toyota engine uses dual injectors? I thought diesels used CCV…