Today at Atelier Kaz - ex-Honda R&D, F1, Indy/CART engineer

Removed TH body as reported earlier, I felt some hesitation.




This is back side of the TH body.

Although the TH butterfly edge was not too bad, the body and idle air port
were covered in thick sticky black gunk.
Will give it a good wash.

The idle adjust screw was covered in thick locking paint so
never being touched in the past.
Will check the idle rpm in Open loop mode by shorting the SCS terminal.
Hope I don’t need to adjust it considering the low mileage.




Inspecting the VVIS butterfly.
You can operate it by moving the linkage next to the manifold.

Using the fibre scope, confirmed that there were fair amount of
blowby oil trapped at the bottom chamber.
Nothing unusual and if doing similar annual mileage, just take the
intake manifold off in about 8 – 10 years time for thorough cleaning.

All of the butterfly screw heads didn’t show any gap at the base so
at this stage, nothing to worry.




As promised, took the video of noisy WP.
With the new one, you can’t spin it easily and freely like this and of course,
there is no noise.







Inspected the heavily corroded Oil cooler.
It’s not easy to show how deep the corrosion managed to
penetrate through the top hat section of the cooler body but
it was enough for me to concern.

When I first saw the oil leakage from oil cooler on UK based NSX,
I contacted Japan and they were very surprised with the corrosion level.
They never experienced serious oil leakage from oil cooler body on any NSX.

I have seen oil seepage from oil cooler on other Honda models but
all of them were due to the rust chewing into the o-ring section at
the centre bolt with the relief spring.
When the seepage happens, it just looked wet and nothing like the
oil continuously flowing out at alarming rate like it happened on another NSX.

As reported earlier, interesting enough, this oil cooler is also at the
right side of the engine that showed far more corrosion compared to the
left side on this NSX.

It’s hard to predict when it will fail by just looking at it and you don’t
want to peel off the rusted layer for inspection as it may accelerate the
corrosion leading to the loss of oil pressure.

It could fail in near future or it could be fine for another 10+ years.......

After some discussion with the owner,
we decided to replace the oil cooler body this time.