After considering all the helpful advice in this thread, I put in Castrol Edge 0w30 ("German Castrol") at my last OCI.
First, a correction to amend to the linked thread: I originally said I was losing about a litre between 5000km OCI's. I realized I forgot to account for the level difference between OCI's. Redoing the math, it's actually closer to 1.5-2 litres every 5000km.
That being unfortunate as it is, with 2000km on this oil and replacing my PCV valve at 800km after the OCI, I'm still losing oil at exactly the same rate. So, it hasn't gotten any worse, but it's not any better. I'll probably try a 40 at my next OCI.
In the mean time, I want to attack it from another angle by installing a catch can. It may not solve the problem, but it will help me further troubleshoot the source of it.
I've seen a few ways this is done:
1. Sealed can between the PCV valve and the vacuum inlet on the manifold. This theoretically draws most of the nasty stuff out into the can and returns clean-ish vapours to the manifold. I expect this probably won't have much effect on consumption, but I'll be able to say, "yup, that's where my oil is going." The only potential problem I see with this is possibly a slight reduction in the vacuum on PCV (due to it having to travel through the can and additional plumbing), adding more stress to seals.
2. Pulling the PCV valve, plumbing it to a vented can intake, and plumbing the other side of the can to the fresh air inlet. The vacuum inlet on the manifold and fresh air outlet on the intake duct would be capped. This has reportedly seen some success in greatly reducing oil consumption, but having no vacuum on the PCV and only getting fresh-ish, unmetered air seems like a Bad Idea™.
3. Breather directly on the PCV port (no valve) and cap the vacuum port. Obviously, no vacuum and possibly changes the AFR a bit. Still seems like an iffy idea.
What is generally the best setup for this? Are there other possibilities?
First, a correction to amend to the linked thread: I originally said I was losing about a litre between 5000km OCI's. I realized I forgot to account for the level difference between OCI's. Redoing the math, it's actually closer to 1.5-2 litres every 5000km.
That being unfortunate as it is, with 2000km on this oil and replacing my PCV valve at 800km after the OCI, I'm still losing oil at exactly the same rate. So, it hasn't gotten any worse, but it's not any better. I'll probably try a 40 at my next OCI.
In the mean time, I want to attack it from another angle by installing a catch can. It may not solve the problem, but it will help me further troubleshoot the source of it.
I've seen a few ways this is done:
1. Sealed can between the PCV valve and the vacuum inlet on the manifold. This theoretically draws most of the nasty stuff out into the can and returns clean-ish vapours to the manifold. I expect this probably won't have much effect on consumption, but I'll be able to say, "yup, that's where my oil is going." The only potential problem I see with this is possibly a slight reduction in the vacuum on PCV (due to it having to travel through the can and additional plumbing), adding more stress to seals.
2. Pulling the PCV valve, plumbing it to a vented can intake, and plumbing the other side of the can to the fresh air inlet. The vacuum inlet on the manifold and fresh air outlet on the intake duct would be capped. This has reportedly seen some success in greatly reducing oil consumption, but having no vacuum on the PCV and only getting fresh-ish, unmetered air seems like a Bad Idea™.
3. Breather directly on the PCV port (no valve) and cap the vacuum port. Obviously, no vacuum and possibly changes the AFR a bit. Still seems like an iffy idea.
What is generally the best setup for this? Are there other possibilities?