*Does a Hyundai Theta II GDI 2.4L (non - turbo) fall into the category of a known design issue where localized fuel escape concentrations would be a potential issue - or are Hyundai's Theta II GDI 2.4L engine fuel dilution issues of a different nature ?
Originally Posted by dnewton3
The towing and tune clearly are not a concern here; good typical wear and low contamination. Even fuel seems moderate for an EB.
Extended OCIs are at the risk of the owner, obviously. I always advocate for longer OCIs, but when it comes to EB engines, ONLY with proper baseline established, and controlled methodical extension with proper monitoring tools (UOAs, PCs, visual observations, etc). The risks and rewards need to be understood prior to the adventure being undertaken.
NOTE - THE FOLLOWING IS MY OPINION AND NOT PROVEN, SO TREAD WITH THE UNDERSTANDING THAT I CANNOT BACK THIS UP WITH ANY HARD DATA...
https://www.youtube.com/watch?v=Q-I4HhNDJfs
What seems to be of concern to me, with ANY DI high-pressure fuel system such as this (irrespective of OEM brand) is that IF you are seeing high fuel content in your oil, it's probably coming from a direct internal leak of the pump in a localized area. Hence, the cam lobe that drives the HPFP, and the subsequent damage to the pump follower as well. When fuel escapes this style of pump, most all of that fuel is going to be locally distributed FIRST at the point of the leak (in and around that specific area). That will cause the localized oil at the point of leak to be GREATLY diluted, and only then later dilute the whole sump. So while the fuel content of the sump might only be 1% or less in a UOA, the LOCALIZED fuel effect at the lobe where that HPFP exists might be getting hosed down with minute fuel concentrations every single stroke of the HPFP.
I would actually advocate for occasionally removing the HPFP and visually observing for abnormal wear on both the lobe and the HPFP follower. This is why I way it's important to know your unique engine design and issues. And why that ONLY using a UOA is dangerous. I always advocate for UOAs, PCs, and visual observations when the unique engine design demands it.
There are some engines that are VERY reliable and have proven through tens of thousands of UOAs to have good wear and a good reputation. There are times when I will directly advocate for an OCI extension because I'm intimately familiar with the engine design and it's wear traits. (Ford 4.6L; Ford 3.5L Duratec,). These engines do have issues, but they are not avoided by shortening the OCI. For example the internal water pump leaks of the Duratec 3.5L has nothing to do with the oil change interval; you cannot stop the leaks from happening by shortening the OCI duration.
With any of Ford's EB DI engines, they all use the HPFP design that I know of. If I owened one, I'd be personally not only doing UOAs to track the overall engine wear, but I'd also be pulling off that HPFP to track the localized pump wear.
Caveat Emptor.
Originally Posted by dnewton3
The towing and tune clearly are not a concern here; good typical wear and low contamination. Even fuel seems moderate for an EB.
Extended OCIs are at the risk of the owner, obviously. I always advocate for longer OCIs, but when it comes to EB engines, ONLY with proper baseline established, and controlled methodical extension with proper monitoring tools (UOAs, PCs, visual observations, etc). The risks and rewards need to be understood prior to the adventure being undertaken.
NOTE - THE FOLLOWING IS MY OPINION AND NOT PROVEN, SO TREAD WITH THE UNDERSTANDING THAT I CANNOT BACK THIS UP WITH ANY HARD DATA...
https://www.youtube.com/watch?v=Q-I4HhNDJfs
What seems to be of concern to me, with ANY DI high-pressure fuel system such as this (irrespective of OEM brand) is that IF you are seeing high fuel content in your oil, it's probably coming from a direct internal leak of the pump in a localized area. Hence, the cam lobe that drives the HPFP, and the subsequent damage to the pump follower as well. When fuel escapes this style of pump, most all of that fuel is going to be locally distributed FIRST at the point of the leak (in and around that specific area). That will cause the localized oil at the point of leak to be GREATLY diluted, and only then later dilute the whole sump. So while the fuel content of the sump might only be 1% or less in a UOA, the LOCALIZED fuel effect at the lobe where that HPFP exists might be getting hosed down with minute fuel concentrations every single stroke of the HPFP.
I would actually advocate for occasionally removing the HPFP and visually observing for abnormal wear on both the lobe and the HPFP follower. This is why I way it's important to know your unique engine design and issues. And why that ONLY using a UOA is dangerous. I always advocate for UOAs, PCs, and visual observations when the unique engine design demands it.
There are some engines that are VERY reliable and have proven through tens of thousands of UOAs to have good wear and a good reputation. There are times when I will directly advocate for an OCI extension because I'm intimately familiar with the engine design and it's wear traits. (Ford 4.6L; Ford 3.5L Duratec,). These engines do have issues, but they are not avoided by shortening the OCI. For example the internal water pump leaks of the Duratec 3.5L has nothing to do with the oil change interval; you cannot stop the leaks from happening by shortening the OCI duration.
With any of Ford's EB DI engines, they all use the HPFP design that I know of. If I owened one, I'd be personally not only doing UOAs to track the overall engine wear, but I'd also be pulling off that HPFP to track the localized pump wear.
Caveat Emptor.
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