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

Recently, I worked on one of the NSX for the squeaking noise caused by the Front CAT heat shield scratching against the metal bar at the aftermarket diffuser.


After testing the car on the dual carriage way and some heat soak condition as seen in my Blog dated 28/Jan/11, the car was returned to the owner.


Unfortunately, when the owner got off the motor way and drove into the city area, he started to hear the noise again.

He also mentioned that when the engine was cold, there was no noise and when the noise was there, it sounded like coming from the rear left side.


Although it was time consuming service, the skill level was fairly simple but in case I made a mistake, I asked the owner to bring back his NSX to my place again.


I offered him to cover the cost of the fuel for both way and also two of the single train tickets.







On his arrival, the noise was there so first thing to check was the heat shield modification that I carried out last time.


It was still fine and nothing was scratching there so partially relieved .





Then, without stopping the engine, placed the car on the lift and inspected the area with the owner.


As the aftermarket exhaust was quite noisy, it was not easy to pin point the cause of the noise so decided to remove some of the parts to eliminate from the list.


First, I tried to remove the heat shield from the Front CAT but due to the diffuser, it was not possible to completely take it off without loosening the CAT/Exh fixing nuts.


Having said this, the noise didn’t change at all when removing the fixing at the heat shield so very unlikely to be the cause of the noise.


At this point, I thought it will require several hours to work on the car so asked the owner to leave the car with me.

So, the investigation started.



After removing the CAT, by shaking the entire exhaust, similar noise was heard although the frequency of vibration was completely different from the one generated by shaking it with my hand against the one from running the engine.




Before putting back the heat shield, as a precaution, I applied the non-melting high temp spec grease at the fixing points to reduce the friction.