300tdi oil burning

Hi colleagues

I installed a 300tdi engine to my defender last month, drove it for around 600km and now notice that oil level is low.

Is strange since engine doesnt show any obvious signs of wear
- start fast easy cold, even without warming it up
- No oil on coolant
- Drives fast and strong
- Turbo is clean , no sign of oil
- Smokes as any 300tdi
- Intercooler hoses clean
- No oil leak
- Gasket clean
- Open oil cap and no smoke , lubrication as normal

Any ideas or tips what could be the problem?

Thanks

I'd top it up to just below full and keep an eye on it...................

I will refill and keep and eye on it. I checked everywhere but no leaks.

I could think it could be a piston or something but the engine is strong and goes uphill fast with no smoke or problem.

thx