2.4 liter Petrol Injection Engine

I replaced the timing belt and balance shaft belt on my 4x4 pickup (I think L200 will be an international designation - In South Africa it is called the Colt, and in Australia the Triton). All the timing marks, including the marks on the oil pump sprocket were aligned with TDC on #1 cylinder.

I did not locate and secure the oil pump shaft hole with a Phillips screw driver as was required on the diagram I had (it was for an older model, mine is 2001).

The engine started beautifully and idled very smoothly. BUT above 3,000 rpm it becomes too noisy - sounds smooth but far too noisy.

Three questions:

1. Why does the oil pump need to be synchronised so accurately with the crankshaft?

2. Can a small error on this be the reason for noise and vibration?

3. Should the balance shaft timing marks have been synchronised at BDC and not TDC? (it is a 4 cylinder engine remember)

Thanks for whoever's time is used on this.

What's the compression on each cylinder?
The timing could be a tooth off!

Thank you for the note. Having rolled the engine through several revolutions with all the plugs out before reassembly, all the timing marks were all exactly correct.

The engine is in very good health, no compression loss on any cylinder, and no such noise before the replacement - only noise was from the broken balance shaft belt.

Viewing it again first thing in the morning,