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Today at Atelier Kaz - Private NSX Enthusiast, ex-Honda R&D engineer with F1, Indy/CART background

Cooling Sys, Brake OH, etc 01

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Have been working on another NSX since mid January.

Initially, it was brought to me as an emergency for the cooling system and the brake OH.
However, on arrival, the owner told me that he started noticing rattling noise at Off throttle (Off-TH) and somewhat the engine didn't feel like it used to be.

Super low annual mileage so just before visiting me, the owner put about half tank of fresh fuel.

As this is the first time servicing this NSX for me, started with the Health Check and found several things.






Later, when I test drove this NSX, I found that it even made the rattling noise at steady cruising mode at about 2,500rpm.
Before taking this video or even going out for the test driving session, I already checked the VVIS plates/screws with endscope and none of them were rattling.

Compared to my VVIS, there is extra play along the plate shaft axis at the rear side but I don't think that is the cause of the noise.
More like the end stop for closed position bieng hit multiple times rapidly when this noise happens.

Seems like the VVIS diaphgram not operating smoothly, increased linkage friction, linkage spring force overcoming the vacuum force, etc.

Also, not supposed to touch the end stop but looking at the VVIS plate at closed position, looked to be bit too far closed compared to other NSX.

Will loook into this later and if I have to, I already have all the required parts in stock for VVIS service based on the past experience of back order....


















First thing first..... Better wash the car....





Better now.


















The car arrived with coolant level lower than the MIN line but not like empty.












There was no air trapped at the heater core so very unlikely to have head gasket issue but for any cars arriving with low coolant level, I always carry out eng block test.

These days, the garage air temperature is so low that it kills the lithium ion battery and thus, had to take each photo really quickly so couldn't take from the same angle but result looked good.
In fact, while at the stage of 3rd photo, you would see hint of yellow/light green colour if there is even a tiny head gasket issue.






By the way, the coolant came out from the heater core area was like plain water with hint of green.
Should be dark blue/green.....




























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