1991 NSX 25,000 miles. Maintenance??

[stv1991]

Bought a 1991 NSX with 25,000 miles. Car runs/drives great. I know everyone says to change the timing belt, water pump, & water hoses. Which should I have done first? Any other issues that I should go through before driving this car? Just want to get it in tip top shape so I can enjoy without worry.

Thanks in advance...

 

[NSX2398]

The timing belt is probably the most urgent from the perspective of what it's going to cost you if it fails. Most people do the water pump at the same time. It's hard to know by inspection whether the hoses are about to fail or not but the worst case if you blow one is that it will overheat so keep an eye on the temp. I presume you know about the transmission snap ring issue .. if you don't, check it out. Another thing that is expensive to repair if it fails but cheap as a preventative measure, is the replacement of the "power window thingy". The only other key preventative thing that people do is to either replace the harmonic balancer pulley or install a guard.
A great source for newbies is the Wiki .. click on "Wiki" on the action bar at the top of most pages. There is a section for "Caring for your NSX" as well as a "Troubleshooting/Repairing" section.
Welcome aboard and good luck with your new purchase.

 

[mlambert890]

On a 91 Id say TB/WP/hoses for sure... check harmonic balancer while in there... valve adjustment... tune-up... oil change/filter... air filter/intake cleaning... basically the "major" that really needs to be done very 6 years, plus hoses.

In addition I'd say verify that the tires look good and arent too old.

 

[davidf]

So you know for a fact it has'nt been performed yet? Also invest in a main relay. Cheap insurance.

 

[TANTO]

Ah, often the contrarian. While I agree with all above and since you mentioned peace of mind, replacing the timing belt and major cooling hoses is prudent. My 92 has 26k on it and nothing has been replaced. Why? I have inspected the hell out of them and they appear perfect. They have not hardened at all. My guess is the temperature cycles are much more important than age. I will replace them in the next few years, but i'm not in a hurry. I would rebuild the engine myself if it were to pop, so i'm less worried than many cost wise. Point to you is that you may not have to spend 3-4k on all this before you even drive the car.

 

[Honcho]

Ah, often the contrarian. While I agree with all above and since you mentioned peace of mind, replacing the timing belt and major cooling hoses is prudent. My 92 has 26k on it and nothing has been replaced. Why? I have inspected the hell out of them and they appear perfect. They have not hardened at all. My guess is the temperature cycles are much more important than age. I will replace them in the next few years, but i'm not in a hurry. I would rebuild the engine myself if it were to pop, so i'm less worried than many cost wise. Point to you is that you may not have to spend 3-4k on all this before you even drive the car.

The NSX coolant hoses- all twenty three of them- look great right up to when they explode all over the road. I think it's great you found a low mile NSX and that means a lot of stuff should be in pretty decent shape, especially the interior trim and paint, if maintained. You bought the most reliable exotic car in the world, but that does not mean you should skip maintenence, especially a major service. It has been well established over the years that the condition of the timing belt and hoses cannot be determined by visual inspection. Hoses and belts have blown that looked perfectly fine, including my front radiator hose in 2006.

Jimbo explains the timing belt here.

Here is a harmonic balancer that let go. I am sure the owner thought this looked perfectly fine when he inspected it as well. The balancer will eat through the plastic lower timing case like this and then eat your timing belt, resulting in the destruction of your engine.

A new NSX 3.0L engine is about $20,000. A good used one is $5,000 to $10,000. The major service plus balancer plus hoses is about $3,000. Can you drive your car without doing the major? Yes. Should you? Well, that depends on how lucky you are feeling.

 

[nsxtasy]

On a 91 Id say TB/WP/hoses for sure... check harmonic balancer while in there... valve adjustment... tune-up... oil change/filter... air filter/intake cleaning... basically the "major" that really needs to be done very 6 years, plus hoses.

And you forgot to mention the fluids other than oil: transmission fluid, brake fluid. Which actually should be changed more often than every 6 years. (The recommendation from the folks who built the car is every 30K miles or 2 years, whichever comes first.)

I agree that, if you have no knowledge that any of those items has been done, you really need to do ALL of them.

One more note:

I know everyone says to change the timing belt, water pump, & water hoses. Which should I have done first?

These three items should be done at the same time, because there are savings involved in doing so. The extensive labor involved in changing the timing belt is the same as that in changing the water pump, so when you do one, you always do the other, so you don't have to do all that labor again. And there are some labor and coolant savings in doing the hoses at the same time as the water pump.

 

[TANTO]

The NSX coolant hoses- all twenty three of them- look great right up to when they explode all over the road. It has been well established over the years that the condition of the timing belt and hoses cannot be determined by visual inspection. Hoses and belts have blown that looked perfectly fine, including my front radiator hose in 2006.

All 23 hoses? We disagree. Few mechanics even know how to inspect a hose. You pull on the end of a hose stretching it and looking at the ends of the hose with a magnifying glass for microscopic cracks, as well of course as the "squeeze". Sans UV, it's the number and severity of the heat cycles that is the determiner, which are amost nil for a 25k car. I have discussed this in detail with my two freinds that are/were engineers for Goodrich and Ashland Chemical rubber developement. They are the folks that make the "rules", and they make them to sell hoses. It's not based on empirical rubber failure data. I also HAVE read the posts on the subject and frankly the numbers of failures is extremely low overall. I suspect many hose failures are due to thermos momentarily locking closed. That was often the case when i was growing up as a mechanic. Not to flame, we can disagree. It's simply a peeve of mine that folks are being brainwashed into changing these items at what me and my learned rubber research engineers believe are near ridiculous intervals. Just trying to save you guys some money! At 40-50k miles the heat cycles start to matter. JMI

 

[SFNSXguy]

Just to jump into the flames...

I replaced all the hoses in my car at 33,000 miles in 2006... I had owned the car since 1993 (17 years)... lots of those miles were track miles, I figured better safe than sorry.

Afterwords I inspected each and every hose in great detail. They ALL looked as good as new -- perfect!

My $0.02

Your mileage may vary.

 

[tbromley]

You can change the TB - not that I think it would break but I wouldn't bother with the water pump - I mean that's a bearing issue - 25k miles I mean if you aren't planning to drive it a lot then you'll probably be ready to replace the next timing belt due to time rather than miles and you can change out the WP the second time around. If you plan to put a lot of miles on it - replace the WP too.

I've heard the Euro owners manual only says to replace the TB after driving 60k miles regardless of years. There's a lot of stuff like this - man if you can keep a rubber hose on an engine that is exposed and moving hot water around then maybe the timing belt under normal driving conditions is getting little stress. This has been beat to death on this site. You should know however no matter what people tell you - it is you that will be fixing things if something breaks not all us guys giving you advice.

Best advice and safest is to replace at the intervals that are spec'd in the manual.

But is your belt going to break tomorrow - most likely NOT! I'd even say most certainly not but that's just my opinion. One thing for sure you don't hear about em breaking very often more like really rarely - becuase the car was run hard on the track or something or the car was TC'd or SC'd. Under normal driving conditions and spirited street driving I wouldn't worry too much - there have been guys that have had cars like yours that have put many more miles than that on a 91 and not replaced the belt - is that good advice - not really. It's just the facts....you take your own chances - if that belt breaks bye bye engine! So how lucky do you feel?

 

[Honcho]

No flame at all, man. My issue really stems from the folks who buy this car and then don't do the maintenence- often becuase they can't afford it. Then, they have a failure and start bagging on the NSX that "was supposed to be reliable." They quickly move on to Supras, Evos, etc...

By contrast, it sounds like you really know what you're doing and you have all the information, so you're taking a higher level of risk, that's all. All of these maintenence threads boil down to this- failures are expensive on the NSX. Maintenence is less expensive. So, the smart choice is to do the maintenence.

All 23 hoses? We disagree. Few mechanics even know how to inspect a hose. You pull on the end of a hose stretching it and looking at the ends of the hose with a magnifying glass for microscopic cracks, as well of course as the "squeeze". Sans UV, it's the number and severity of the heat cycles that is the determiner, which are amost nil for a 25k car. I have discussed this in detail with my two freinds that are/were engineers for Goodrich and Ashland Chemical rubber developement. They are the folks that make the "rules", and they make them to sell hoses. It's not based on empirical rubber failure data. I also HAVE read the posts on the subject and frankly the numbers of failures is extremely low overall. I suspect many hose failures are due to thermos momentarily locking closed. That was often the case when i was growing up as a mechanic. Not to flame, we can disagree. It's simply a peeve of mine that folks are being brainwashed into changing these items at what me and my learned rubber research engineers believe are near ridiculous intervals. Just trying to save you guys some money! At 40-50k miles the heat cycles start to matter. JMI

 

[stv1991]

I am going to park the car until next spring. There is some customization I want to do before I start driving this car on a regular basis. I will for sure have the TB & WP changed out next spring before driving it as well as having all fluids changed. Water hoses I will risk as I won't really be driving this car too far from home. I will inspect them though and change any that look suspicious. Anything else I should consider? I will be budgeting about $4K for maintenance. I'm thinking that will cover this would that be about correct?

 

[TANTO]

STV- I know someone mentioned this, but i want to +1 the brake, clutch, and ABS fluid. "Exercise" the ABS both before and after the fluid change. Take your time to get all the old stuff out. I would do these things right away. And then coolant. And a couple of bottles of fuel cleaner. And... and... er uh, just forget my earlier posts and do it all.