Timing Belt Service

[bbvnsx]

Hi, Bruno.

Hi Kaz, thank you very much for your reply!

Could you provide us with the following info?


General info/spec of your NSX.
Engine size, AT/MT, modifications on engine, exhaust, intake, ECU, adjustable cam gears, etc, etc, etc.

1993 NA1 3.0 MT with ~25.000 miles

The car is stock except for the DF scoop + UNI filter

The usage of your NSX.
Every day car, street only or street/track = 80/20%, street/track = 95/5%, etc.


The driving style of your NSX.
Always hit the rev limiter, very gentle, etc.


The driving condition of your NSX.
Hot, cold, never in the rain, near the sea, high altitude, stop-and-go-traffic,
twisty mountain road, short distance only, long distance only, high cornering G force, etc

I do aprox. 1300 miles/year but i try to drive the car once a week for about 30/60 miles except when raining. The car is stored on a heated garage but I'm located near the sea (~1,5 miles)

Weather in Portugal is very good so the car is never driven below 0ºC temperatures and there are no salty roads where I live etc.

I drive my NSX very gentle until the engine is hot, (aprox. for 15 miles) than i'll increase gradualy RPM's and drive the car fast on twisty mountain roads or highway (i'll avoid hit rev limiter but i'll rev the car above 7000 RPM's when driving fast and going throug gears down/upshifting). I don't track my car.

Any significant changes/modifications from OEM spec on your NSX.
For example, super/turbo charger, different INJ, big brake, flywheel, different ACG, A/C compressor removed, etc.

No significant changes for now, and i don't plan S/C my NSX..., but i do plan changing my ABS and ugrading to stoptech BBK in the future (2014) and also go with lightweight flywheel and if i find the right one maybe i'll change the exhaust too

Are you doing this TB service by yourself?

I'll be taking my car to the local Honda dealer where I usually do my maintenance... Wish i had a kaz here

Thank you

[bbvnsx]

Maybe add the timing belt tensioner + spring and the oil cooler 'figure of 8' seal?

yes, I will change that part too , would it be recomended to use this one instead?:

http://www.scienceofspeed.com/produc...eed/tensioner/

Any recorded failures of this particular part?

[Kaz-kzukNA1]

Hi, Bruno.
As NSXGB mentioned in his post #6, that list is a good starting point.


Please replace the WP at every TB service regardless of the mileage covered since your last TB service.


As you live near the sea, it’s very likely that some of the bolts around the TB covers are already corroded.

Therefore, I strongly recommend you to replace the 11 x TB cover short bolts + 2 x longer ones.
The person who will be working on your NSX for the next TB service may have big time dealing with lower three bolts behind the crank pulley and above the oil cooler if not replaced.

For the same reason, you must replace the TB tensioner special bolt. The bolt head is exposed to outside and it will be corroded by now.


Based on your driving style, no track session, no super charger in the future, brake performance including future upgrade, etc, I don’t see the point in using the aftermarket TB + oil pump gear + crank pulley.
For all of them, OEM ones are well over the required spec for your conditions.

Regarding the OEM crank pulley, its main purpose is shifting the resonance frequency at the TB under certain condition to protect the TB and not just acting as the damper for aux components such as A/C compressor, etc.
So, personally, I would stay with the OEM one.

You may want to check the condition of all four Eng/MT mounts especially if you do lots of twisty mountain road driving with hard acceleration and applying hard braking.


In US, if you drive very hard, there seems to be several occasions where the car can go through long high G corners even on the street resulting in oil starvation. I think this is the reason why the owners opt for the aftermarket baffle plate inside the oil pan.
For your conditions, I don’t think you need it.
For your reference, in Japan, we actually remove the aftermarket baffle plate from the oil pan because we found negative effect when going through the twisty roads.


For C30A engine, unless you modify the internal engine parts such as cam shaft, there is almost no power gain in using the aftermarket parts at the intake air side even with aftermarket header, exhaust, CAT test pipe combined. You may get better sound and throttle response by using them, though.

Therefore, using the aftermarket air filter, air box, air scoop, big bore throttle need careful consideration. Individual throttle butterfly is for torque curve tuning so unless you can variably change the funnel length, you will gain in one region but loose in the other side.

If using aftermarket air filter with specific filter oil, you must clean and apply the oil carefully. Otherwise, the excessive oil will stick on the TH butterfly and will cause new issues.


Spark plug is OK for 60K miles but best to check them regularly for moisture corrosion.
Don’t get confused by the light brown marking at the insulator body caused by the corona discharge.
It’s perfectly normal and you need to look for the rust that is more like dark brown.


If you are looking for long ownership of your NSX, then it’s good idea to take engine compression at least once a year.
Also, at the time of TB service or adjusting the valve clearance, you may want to ask to take compression before/after the service.


Before draining the coolant, you may want to carry out the engine block check.
From time to time, you won’t be able to detect the engine issue unless it is tested with the engine fully warmed up.
This was the case for several owners in the past.


If all of your coolant hoses were never replaced in the past, then it’s well over due for the service.
As you must drain the coolant for WP service, good idea to do it at the same time.

At the same time, best to replace the thermostat, coolant header tank cap and if your header tank is creamy or yellowish and not super white, replace it before it starts cracking.


If replacing the LMA, you must remove the VTEC spool valve so you will be forced to replace the two filters at each solenoid.
Your NSX is 93 model so they are the same ones as the original models.
Just double check and order the correct ones as the change over happened during 94 and it depends on the engine no.
Also, you will be removing all four cam shafts so you must replace the four black round cam cap discs and four brown cam seals.
Lots of NSX are showing oil seepage from the cam cap disc area.


If removing the intake manifold, be careful with the knock sensors.
If you don’t have spares, don’t touch them.
With the age, it could easily crack/break off from the base.

Having said this, from time to time, I noticed that they were already dead (breaking off from the base) and may cause unnecessary IG timing retard.
And you can't access them without removing the intake manifold so may want to replace them while in there although they are not that cheap.....


While working at the top side of the intake, check the state of IAT (Intake Air Temperature) sensor.
It’s not expensive so you may want to just replace it.
If re-using, replace the O-ring.
If it is very dirty, it will send out the wrong fuel timer.


You may want to replace the oil pan gasket but to do it properly, you must remove the front exh manifold down pipe.
Therefore, if you are installing the header in the near future, best to do it at the same time.


I think these are enough for the time being….

Kaz

[bbvnsx]

Thank you very much for your reply Kaz!

I'll be using all the good advices you provided and I'm also going through your entire blog Thank you very much for sharing all this information!

Would really appreciate if you could give me your advice having in mind the following:

Based on your driving style, no track session, no super charger in the future, brake performance including future upgrade, etc, I don’t see the point in using the aftermarket TB + oil pump gear + crank pulley.
For all of them, OEM ones are well over the required spec for your conditions.

Regarding the OEM crank pulley, its main purpose is shifting the resonance frequency at the TB under certain condition to protect the TB and not just acting as the damper for aux components such as A/C compressor, etc.
So, personally, I would stay with the OEM one.

Sorry for not explaining these before, but as I only put ~1300 miles/year on my NSX I was thinking about extending my TB service to 8 to 10 years instead of the recomended 6 years, so this was one of the reasons directing me to ATI Damper (more durable) + Power Enterprise TB (more durable plus stronger than OEM to prevent damage if the improvable ressonance frequency occurs)...
Toda oil pump was just for the peace of mind and to take the oportunity as I'm doing this big maintenance, so in the improvable case of over revving my engine i wouldn't be immediately in panic of a major problem
Have you heard or experienced problems with this aftermarket parts?

If all of your coolant hoses were never replaced in the past, then it’s well over due for the service.
As you must drain the coolant for WP service, good idea to do it at the same time.

At the same time, best to replace the thermostat, coolant header tank cap and if your header tank is creamy or yellowish and not super white, replace it before it starts cracking..

All my visible rubber parts are like new (you can see them here #68: ,http://www.nsxcb.co.uk/showthread.ph...e-Covers/page7 ) not a visible crack or even color alteration and if i gently squeeze my hoses they really feel in great shape..., do you think i should replace the hoses regardless of this or should i take the car to the dealer and check with them...? Don't you want to move to Portugal? it would be so much easy...

Also, you will be removing all four cam shafts so you must replace the four black round cam cap discs and four brown cam seals.
Lots of NSX are showing oil seepage from the cam cap disc area.

Can you please confirm the following part numbers:

4 x RUBBER, HEAD COVER SEAL (12513-PR7-A00)
4 x OIL SEAL (29X43X8) (91213-PR7-A01)
8 x WASHER, SEALING (20MM) (12209-PR3-000)
4 x O-RING (6.8X1.9) (91306-PJ4-000)

You may want to replace the oil pan gasket but to do it properly, you must remove the front exh manifold down pipe.
Therefore, if you are installing the header in the near future, best to do it at the same time.

I replaced this gasket in August (when changing my oil), if i decide to change the oil pump gear can i reuse the gasket or will i have to get a new one?

Thank you very much! merry christmas

Bruno

[goldnsx]

- OEM crank pulley with ATI Super Damper

I don't see a crank pulley shield in the list above. This is a must for every NSX but only if you go with the OEM crank pulley.

I've a spare pulley shield and LMA set for spare I could sell you cheak if you're interested.

[Nytram]

Sorry for not explaining these before, but as I only put ~1300 miles/year on my NSX I was thinking about extending my TB service to 8 to 10 years instead of the recomended 6 years, so this was one of the reasons directing me to ATI Damper (more durable) + Power Enterprise TB (more durable plus stronger than OEM to prevent damage if the improvable ressonance frequency occurs)...


Excuse me butting in but I have just booked my car in with Kaz for the engine refresh stage 1 early next year, and I am under the impression that once done I don't have to worry about the TB/WP for 10 years anyway due to the level of detail involved with Kaz's excellent service.


Just a thought but if all the UK NSX's move to Portugal maybe Kaz would follow

Regards Martyn.

[Kaz-kzukNA1]

I used to go Estoril regularly and stopped counting the number of travel I made long time ago.
Same goes for Barcelona. I think I went there easily more than 150 times.
One time, I thought I was living in Imola because I spent so many weeks there within a few months.
Good old days.....










Unless your NSX is track day only like above (courtesy of Mr Toyoizumi at KSP Engieering, Japan) or,



until your engine is tuned to this level (courtesy of Toda Racing, Japan), then OEM parts are fine.



It’s your NSX so the decision is up to you.



Regarding the TB service schedule......
I wrote this on this site somewhere in the past......

I don’t follow the UK service schedule because my NSX is JDM and I bought it as a new car in Japan so no warranty from Honda UK any way.

In Japan, for almost all cars, the TB service schedule is every 100K Km or 60K miles without age related conditions.
Having said this, there is a general consensus among the owners as well as the garages to carry out the TB service every 10 years or 60K miles whichever comes first.

As my NSX is everyday car, it will hit 60K miles before 10 years period and as I used to use my NSX for R&D purpose, some of the parts were on purposely replaced earlier/later than the recommended interval.
I’m also using the parts from different NSX models but even under these conditions, I never experienced any issues using the TB related OEM parts.
Even the Type-R/NSX-R that has higher acceleration/deceleration effect on the TB is using the same OEM parts as the standard models.

I’m not familiar with the TB service schedule in Portugal but I think it is the same as UK as I think it is following the European Honda service schedule.
If that is the case, then for your 93 model, it should be every 5 years (not 6 years) or 60K miles whichever comes first.

For the UK owners who took/will take my Engine Refresh service, if their NSX is registered before Jul/98, I’m advising them that they only need my Engine Refresh service every 10 years.
They can use the standard service for the next TB service in 5 years time after taking my Engine Refresh.
Personally, I don't see the point in not following the UK service interval if it is purchased as a UK car but it's up to the owners to make their own decision on whether to stay with the UK TB service interval or not considering the warranty conditions.

On street driving condition, you won’t be able to keep the rpm at the specific window where the resonance happens.
It’s such a small window and unless you are running the engine on the dyno, you won’t be able to hold the rpm steady.




If you are not sure when was the last time your coolant hoses were replaced, then I would just replace all of them.
Please remember that the radiator is also a consumable parts.
It will crack at some point.

If your hoses were replaced within the last several years, you should be able to see the year/month/date stamped on some of the hoses.


It’s the same as the TB.


If you visit the following blog http://www.nsxcb.co.uk/entry.php?698...rvice-Interval
and please take a look at the 1st photo.

If you can tell which TB is mine that has covered about 60K miles, then your judgement on your existing coolant hoses would be fine.
You have better knowledge than me because I can’t tell the condition of any rubber parts by just looking at it.......


If your hoses were never replaced in the past, it would be 19 years old by now and it’s just a gamble on guessing when it will burst.

Again, it’s your NSX so decision is up to you.

Sounds bit strange for someone willing to pay the extra money for the overspec TB/crank pulley/oil pump gear and yet not replacing the potentially 19 years old OEM coolant hoses.
To me, the priority should be the other way round.





Regarding the crank pulley shield........
I don’t know whether it is covered by the PL insurance like the OEM parts so it’s up to the owner to make decision with his/her own responsibility. My view as follows;

http://www.nsxcb.co.uk/showthread.ph...2377#post92377

http://www.nsxcb.co.uk/entry.php?640...esh-Stage-1-10

This shield seems to be very popular in US.
In Japan, we have similar total number of NSX as US and as far as I know, very little number of NSX installed this shield.
Mainly because the crank pulley is replaced regularly in Japan as it is a 'must' procedure at least at the time of TB service for street driving conditions.
If your NSX is modified or used on track, the owner will be replacing it at earlier stage.

I only spent few years in US but even with this limited experience, I can say the driving condition is quite different between US and Japan so that is another big factor to consider.
As long as the crank pulley is replaced regularly, personally, I don’t feel the need for the shield but again, it’s up to the owner.



The 4 parts no. that you listed in your post are already included in my parts list that NSXGB mentioned in his post #6.
Just one thing.
You only need 4 off 12209-PR3-000 and not 8 of them.



It will take more time and cost to clean/degrease the existing oil pan gasket thoroughly before it can be reused than replacing it with a new one.
It’s not that expensive.
I prefer using the later spec one with liquid gasket on both surface.
It’s softer than the original design one so better chance of sealing the uneven surface at the oil pan if it was previously over torqued.


Kaz

[bbvnsx]

I’m not familiar with the TB service schedule in Portugal but I think it is the same as UK as I think it is following the European Honda service schedule.
If that is the case, then for your 93 model, it should be every 5 years (not 6 years) or 60K miles whichever comes first.

You are right! is 5 years, i guess i'm spending to much time on prime and got confused with TB schedule in US...

If you are not sure when was the last time your coolant hoses were replaced, then I would just replace all of them.
Please remember that the radiator is also a consumable parts.
It will crack at some point.

I'm pretty sure they were never replaced, so I added the coolant hoses to the list, thank you!

You have better knowledge than me because I can’t tell the condition of any rubber parts by just looking at it.......

Lol...! that was funny!

Sounds bit strange for someone willing to pay the extra money for the overspec TB/crank pulley/oil pump gear and yet not replacing the potentially 19 years old OEM coolant hoses.
To me, the priority should be the other way round.

Not at all, i have no priority... I was just asking because I'm curious guy . I know very little about mechanic, but unfortunately Honda parts are really pricey in Europe so I'm collecting all the information i can so i can get the needed parts from US... for example the OEM crank pulley would cost aprox. the same here at the dealer as the ATI damper from US... not trying to economize on parts, on the contrary... only trying to get the best parts at the best price.

The 4 parts no. that you listed in your post are already included in my parts list that NSXGB mentioned in his post #6.
Just one thing.
You only need 4 off 12209-PR3-000 and not 8 of them.

Thank you for the information!

It will take more time and cost to clean/degrease the existing oil pan gasket thoroughly before it can be reused than replacing it with a new one.
It’s not that expensive.
I prefer using the later spec one with liquid gasket on both surface.
It’s softer than the original design one so better chance of sealing the uneven surface at the oil pan if it was previously over torqued.

Added that part to the list too!

Thank you very much

Bruno

[bbvnsx]

I don't see a crank pulley shield in the list above. This is a must for every NSX but only if you go with the OEM crank pulley.

I've a spare pulley shield and LMA set for spare I could sell you cheak if you're interested.

I've sent you a PM

[jpspringall]

Hi all,

Mild thread hijack, but its along the same lines, as i'm looking at getting my timing belt service done too. So was looking for a list of parts that I need to order.
Would be I correct in thinking that if I gave my Honda Dealer a list of parts from http://www.nsxcb.co.uk/showthread.ph...4593#post74593
Would have everything covered?

Happy New Year To You All.

James