Direct injection and valve deposits? ??

[j_mac]

Can someone in the know describe the problem with the intake valves collecting deposits in the direct injection engines?
I just bought a new Hyundai Accent with DI and want to know what oil to run in it.
What is the nature of the problem? I'm assuming that oil vapors from the PCV system are finding their way onto the valve and building up. Is this right?
Is synthetic oil less likely to cause build up because of its resistance to heat degradation?
Or am I completely off base?
Any engineers or smart laymen out there with adivice or descriptions?

 

[d00df00d]

Originally Posted By: j_mac
I'm assuming that oil vapors from the PCV system are finding their way onto the valve and building up. Is this right?

Yes. EGR can contribute, too.


Originally Posted By: j_mac
Is synthetic oil less likely to cause build up because of its resistance to heat degradation?

If properly formulated, yes.

It must also resist fuel dilution. That's less of an issue nowadays than it used to be, but it's still a consideration; even if your engine doesn't fuel dilute any more than the average port-injected engine does, it's still more important to keep the effects under control.

Also, since all oils produce vapors to some extent, it's best to pick one that is optimized for low deposit formation. If you can find a low ash oil (e.g. Mobil 1 ESP or similar) that also meets the specs for your engine, that might be best.

 

[demarpaint]

HTH

https://bobistheoilguy.com/forums/threads/solutions-for-di-engines.156413/

 

[Sayjac]

Quote:
What is the nature of the problem? I'm assuming that oil vapors from the PCV system are finding their way onto the valve and building up. Is this right?
You might find this recent article informative.

As well as the threads/posts from a Google Bitog search.