DI oil bypass filter

[C4Dave]

Originally Posted By: Danh
Originally Posted By: C4Dave
Timing chain wear on GDI engines is caused by the high pressure mechanical pump being driven by cam gears or directly by the chain. Since the pump pressure is so high (several thousand psi), a much larger load is put on the chain. I don't think better oils or filters will help with the mechanical stretching of the chain.


So GM responded to premature timing chain wear in DI engines by reprogramming the IOLM to require more frequent oil changes because.....?

I don't know that is the case, but if it is my guess would be that oil is being diluted by gas and not lubricating properly. This would also happen to the very best oils and filters.

 

[Danh]

Originally Posted By: C4Dave
Originally Posted By: Danh
Originally Posted By: C4Dave
Timing chain wear on GDI engines is caused by the high pressure mechanical pump being driven by cam gears or directly by the chain. Since the pump pressure is so high (several thousand psi), a much larger load is put on the chain. I don't think better oils or filters will help with the mechanical stretching of the chain.


So GM responded to premature timing chain wear in DI engines by reprogramming the IOLM to require more frequent oil changes because.....?

I don't know that is the case, but if it is my guess would be that oil is being diluted by gas and not lubricating properly. This would also happen to the very best oils and filters.


Lubrizol says, in an article about the motor oil challenges in TGDI engines: " A second issue is that the particulates entering the oil via blowby gases increase wear rates. A number of OEMs have noted issues with cam-chain wear when they switch from port injectors to GDI.". Lubrizol doesn't note fuel dilution as a problem or a challenge.

 

[UG_Passat]

I don't recall this being an issue on VW's and Audi's with timing chains.

timing chain stretch is due to the metallury of the chain components, manufacturing of it, vs. the shear strain applied.

this is different from the abrasion of particulate matter.

 

[Danh]

Originally Posted By: UG_Passat
I don't recall this being an issue on VW's and Audi's with timing chains.

timing chain stretch is due to the metallury of the chain components, manufacturing of it, vs. the shear strain applied.

this is different from the abrasion of particulate matter.


You may be right. But the OP's question was whether a bypass filtration system could help with a DI engine. As Lubrizol says fine particulate matter resulting from DI combustion 1) does contaminate the engine oil and 2) is probably correlated with increased timing chain wear for some OEMs, it's not unreasonable to assume it could be helpful.

Whether it makes a difference in the real world, or the problem couldn't be addressed more simply with a sensible OCI - who knows?