NSX Health Check Service

[Kaz-kzukNA1]

Air filter box was removed, TH pedal was kept to the floor and the compression was measured. The absolute value is just a reference and although they were fine, the deviation was slightly larger than expected. Later, I found that the valve clearance was out of spec on some of the cyl even they were adjusted in the past.


The valve/head cover was removed.
The route of blow-by gas was changed on the later NA1 and NA2 engines.
As it was still at low mileage and the engine oil was replaced regularly, the backside of the valve cover was quite clean even without the usage of oil catch tank.


Remove the old gasket and seals.
Clean the head cover at this stage and let it dry.
Then, install the new cover gasket and plug hole seals using small amount of liquid gasket. This will allow well enough time for the liquid gasket to set before re-installing it back on the engine. Keep them in a clean place.


Now I understood why there was so much oil leakage for such a new car. When the valve/head cover was re-installed after the valve clearance adjustment last time, the cover gasket was kinked and got caught between the cover and the engine head. Thus, it was not possible to achieve good seal. Surprisingly, it was the same for both Fornt and Rear cover and thus, the oil was leaking from both Front and Rear exhaust port side.

[Kaz-kzukNA1]

No wonder why I had to spend many hours cleaning the engine.


At the end, I think it was quicker to just take out the engine to clean the outside of engine thoroughly because even I spent many hours, I couldn’t get my hands behind the exhaust header flange as well as some of the area below the camshaft black cap. Another reason for why the NSX specialists in Japan take out the engine even just for the TB service.

As I don’t have access to engine clean room yet, all the doors and windows had to be closed. Even in UK, at that time, it was so hot and humid that I felt like working in the garage at Malaysia GP.


Looks like the person who carried out the valve clearance adjustment didn’t clean the residue of liquid gasket. Looks like the white one is the Honda bond from the factory and the black one was used last time.


Align the white marker on the crank pulley to the twin arrows on the TB lower cover to set #1 cyl at TDC.

[Kaz-kzukNA1]

Start removing the bolts from the TB lower and mid rear/front covers. As expected, some of the bolts were heavily corroded and had to be replaced with the new one.



As mentioned above, the oil was leaking from both the front and rear head covers at the exhaust port side.
Because of this, the rubber seals at the front, rear and lower covers were all wet but they did a great job on protecting the TB.

Unlike my old Prelude, there was no trace of oil at all on the TB.

These seals are going to be replaced with the new ones.

[Kaz-kzukNA1]

As we don’t know the history of the engine, it is important to first check the current alignment of the TB against the marking on the Cam gears and TB cover plate.
This engine was fine and it looked like the TB was never removed since it left the factory.


In order to get some reference when installing the new TB, it is good idea to put some markings on the existing belt and transferring them to the new one. These are reference only and you must check the timing by carefully looking at the line on the TB cover plate and the cam gears.


WP removed. The shop towel at the right is covering the hole for the Oil level dip stick. Make sure to cover it before removing the WP as you may spill some coolant.

The new and old WP. Although it was at very low mileage, the old WP was already showing rust on the impeller.

Another reason for why it would be best to replace the WP at the time of TB service regardless of the mileage.
I don't want to rely on this rusty WP for many years until the next TB service....
Quite often, people will only inspect the bearing by rotating the WP without removing it and thus, no chance to check the impeller side.

Special bolts used for the WP. You can re-use them by cleaning the old seal/lock and applying liquid gasket like Honda bond. I just use new ones as it is quicker and possibly cheaper considering the amount of time required to prepare the old ones. Remember to clean the thread hole on the engine side as well although the space is very limited.


Once the new WP installed, make sure to carry out vacuum or pressure test on the coolant system before going any further. You don’t want to find any issues on the coolant system after you put everything back in place only to disassemble again.

More to follow.....

[goldnsx]

Good work, Kaz!

One note, I've seen that the spark plugs were treated with anti-size in the past which looks like copperpaste. I do not favor it. I use hightemp ceramicpaste which is electrically neutral.

[Timage24]

[QUOTE=Kaz-kzukNA1;74842]Hi, Tim.

I'm not a fan of Year model as sometimes, people get confused with registered year against Year model.
You may have 97 registered NSX but not necessarily 97 Year model NSX.

The best is to check against the VIN but if you check the above photos and 100% sure that your NSX is DBW, then your Main Relay is located around the right shoulder of your driver seat for RHD model.

Wow, more than GBP109 for the Main Relay.....
I'm quite sure if you ask Andy at vtecdirect, he would be able to source it much cheaper.
I always keep one each in stock at my place for owners.
Depending on the exchange rate and delivery charge from Japan/US, I would assume it would be about GBP50.00.

Kaz Sir, you astound me with your NSX knowledge.

DBW confirmed for me now. The Honda guy did try to tell me that my car was only registered in '97 but made in '95 so your pic and explanation clear everything up.

I only used the short cut for demo purpose and have gone through vtecdirect but they said £90 - £110 and that was roughly 60% cheaper than main dealer !!! i'll phone them on monday to see what the crack is.

anyway, thanks for the help and may the gods bless you with a golden NSX trophy or something for all the help you give people.

cheers

[Sudesh]

Your guy cant be up to much in reference to NSX's! As there are a few differences in a genuine 97 vs 95, one small thing in particular, the 3.2 and 6 speed box lol

Kaz Sir, you astound me with your NSX knowledge.

DBW confirmed for me now. The Honda guy did try to tell me that my car was only registered in '97 but made in '95 so your pic and explanation clear everything up.
cheers

[Silver Surfer]

Your guy cant be up to much in reference to NSX's! As there are a few differences in a genuine 97 vs 95, one small thing in particular, the 3.2 and 6 speed box lol

Depends on which month of 1997 ? No?

SS

[Sudesh]

Yeah your right, that's why I mentioned genuine 97 as they should be 3.2 - 6 speed. Not referring to DBW as that came in earlier, but if a NSX mechanic looked at an NSX, I'm sure they could tell the difference in a 95 car to a genuine 97 due to those initial points.

Depends on which month of 1997 ? No?

SS

[Sudesh]

In order to re-install them at the same location, they were marked with the cyl

Kaz I always do the same, but very interested to hear your points in why the front and rear banks are marked as RR and FR when they look the same? I know the front coil packs installed are connector side down, on the rear they are installed connector side up, but still wonder why they are marked as RR and FR as I cannot see any difference?