Oil Drain Crush Washer

Yes. The synthetic oil companies have been claiming repeatedly over the
years that they have solved the seal problem but it keeps cropping up -
either the seals would dry up and crack or get too swollen and soft. The
seal material, a mix of nitrile and buna rubbers, was of course chosen for
optimal effect with petroleum lubes.

When Mobil1 went "Tri-synthetic" one of the ingredients was an ester, I
think diisodecyl adipate, at least that's what Valvoline used to use...
which is a lubricant *and* plasticizer... the latter effect helping to
condition seals - IOW just enough swelling action on the rubber but not too
much.

I know what you mean but I want to see for myself what the stuff is
worth. So far, in my '99 Integra, at 30K miles of Mobil1 after the 1st
20K on Castrol GTX, I think I see more cam lobe scoring than I ever saw
with my '92 Integra on GTX for 130K miles. Need to check the data more
carefully.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

 

So I suppose if everyone else jumped off a cliff, you would too?

 

You can read the thread and note that I do not put synthetic oil into my Honda.

My comment was an observation that a lot of people use synthetic oil and
apparently with no ill effects.

"Popularity" here translates to a somewhat scientific database of positive
outcomes.

 

The reason I asked is that my daughter's boyfriend just bought a one year
old Mitsubishi with 20k miles and the valve cover is already leaking. I'm
wondering if leaky valve covers might be a common Mitsubishi weakness.