Valve Adjustment

[Big_D]

I have a 91 and I am taking it in today for the 60K mile service. According to the maintenence records, the valves have never been adjusted. (I only have records back to 20K miles) My tech recommends doing this now. Apparently there are no tell tale signs that they need adjusting untill it is too late, so I am going to go ahead and have it done along with the rear cam plugs.

Id like to find out at what mileage have your cars valves been adjusted?

Thanks in Advance

I did see this link online with some photos and how-tos
http://www.danoland.com/nsxgarage/valve/valve_clearance.htm

 

[Aero]

About two years ago at 46k miles when the timing belt and bunch of other prevenative maint done. Doesn't seem like it was much $$ since all the other stuff was being done too.

 

[DocL]

I had mine done at 15k, 30k, and 56k as part of the routine services.

 

[drew]

Apparently there are no tell tale signs that they need adjusting untill it is too late,

Too late for what? Your mechanic's boat payment???

It appears that NSX valves seem to stay within spec for a very very long time. Way past 30K miles and they stayed within spec for me within 60K miles.

However, you will need an adjustment, if you put in new cam plugs.

Otherwise: very super probably unlikely that you need an adjustment.

Drew

 

[Larry Bastanza]

After too many NSX valve adjustments to count, I have only had one car that came to me that EVERY valve was adjusted properly. Just my observation.

I agree with Drew, if you have cam plugs done all clearances will need to be checked, they will probably be as they were before, but I ALWAYS check them after cam plug installation.

HTH,
LarryB

 

[Autophile]

I had my valves adjusted recently at 48k miles. For what it's worth, I did notice a little less valvetrain noise after the adjustment.

 

[nsxtasy]

I've had mine adjusted at least once every 15K miles, which is what Honda recommends in the maintenance schedule in the owner's manual and service manual.

 

[Daedalus]

I did mine at 51k. They were all out of spec, but by less than .002 each. Keeping things in perspective, that's about 1/2 the thickness of a sheet of paper. I recall cylinders 5 and 3 were the trickiest on the exhaust side due to location and tool clearances.

 

[96 NSX-T]

Here is my reply-here

 

[Big_D]

Here is my reply-here

Wow, sounds like you got lucky on that deal. Congrats... How many miles on the car?

 

[96 NSX-T]

Wow, sounds like you got lucky on that deal. Congrats... How many miles on the car?

When I was going up, I hit 50,000 at the Il./Wi. border. What kills me is how great the car ran before, of course now it is better than new:biggrin:

 

[OLDMNSX]

Well guys, I purchased my NSX with 96k miles. I have no idea if or when they were adjusted. I drove the car from Dallas, TX to Boise,ID and started working on it. Timing belt, water pump etc..........while I had the valve covers off I adjusted the valves.

It took me 45 minutes to do the valves, with the engine already being opened up for the timing belt change. I am glad I did it, but it was a waste of time. I think that I adjusted about half of the valves, to make them perfect, but it was only .001 or less.

It had been so long, 2 1/2 months worth of maintenance, since last driving the car that I would not be a good witness as to any change in performance. I can't imagine that there was any.

Brad

 

[Big_D]

Just got the car back from Jerry at Greenlight Honda in San Diego. He replaced the rear cam plugs and adjusted the valves. He said that he could tell that the valves had been adjusted before, but the exhaust valves in the rear had not and were tight. I am glad I had it done. Now I am good for another 30K before I have it done again.

Thanks for the replies.

 

[nsxtasy]

Now I am good for another 30K before I have it done again.

According to the service manual and owner's manual, you should do it again in 15K miles, and not wait till 30K.

 

[Big_D]

According to the service manual and owner's manual, you should do it again in 15K miles, and not wait till 30K.

I understand that the manual states that, but is that really necessary? I thought that it was determined later on that the valve adjustments are only required after 30K. Maybe that is for the 3.2...

 

[nsxtasy]

I understand that the manual states that, but is that really necessary?

Based on Larry's post above - yes, absolutely!

Of course, if you really don't care how well your car runs or care about preventing more costly repairs, and you'd rather save a few bucks and run that risk, you can skip all the scheduled maintenance entirely...

 

[53heloFE]

He said that he could tell that the valves had been adjusted before, but the exhaust valves in the rear had not and were tight.

I'm not a valve train expert by any means, but wouldn't the valves have to be set tight to be tight? From what I understand valves don't tighten up. Honda doesn't set them like that from the factory do they? Tight can = bent right? So isn't it safer to leave them on the looser side than the tight side? All within spec of course.

 

[Big_D]

Based on Larry's post above - yes, absolutely!

Of course, if you really don't care how well your car runs or care about preventing more costly repairs, and you'd rather save a few bucks and run that risk, you can skip all the scheduled maintenance entirely...

I suppose its better to be safe than sorry. Every 15K then.

 

[Silver F16]

Based on Larry's post above - yes, absolutely!

Of course, if you really don't care how well your car runs or care about preventing more costly repairs, and you'd rather save a few bucks and run that risk, you can skip all the scheduled maintenance entirely...

While you are at it, you should change your air in your tires along with the windshield washer fluid.

It has been documented that the late models, adjustment intervals are quite long, something in the order of 15K, then 90K. Either that or 30K, then 90K. The valvetrain design has not changes from the 3.0 to the 3.2 liter engine. The only difference being slightly bigger valves. The first adjustment is important due to break-in and engine wear that occurs early on. AFter that, it is pretty stable and doesn't move much. The 91 manual does call for adjustments at every 15K, but Honda learned from that and extended their recommended intervals on late models.

Granted, if you are doing track events every weekend, that is a different story. But for normal driving with a few track events every year, after the first adjustment, the next one should follow at 90K.

If you have actually done the valve adjustment yourself rather than pay the Master certified Acura mechanic to supposely adjust your already-in-spec valves, so you can have peace of mind every 15K miles, you will realize that those valves really do not move much, if at all. Stop pissing your money away. If you are not running the car above the rev limiter and you are changing your oil on a regular basis, you are fine.

On our car, the valves typically loosen up with wear. IF it gets noisy or your 90K is up, go for the adjustment. No damage to engine if the valves are a bit loose, just a little noisy. IF it is too tight, then you can burn the valves, but that shouldn't happen unless it was adjusted too tight to begin with.

It is important to have your valves done by someone who is detailed. The tolerance one set of valves (intake set, If I remember correctly) is very tight. Something in the order of 0.007 to 0.008. You get one thousands to work with. Whereas on the exhaust side, you have a two thousands tolerance to work with. Point here isn't to go over board and do it often, but to get someone to do it right to begin with and leave it alone until 90K miles.

Enjoy your ride

 

[nsxtasy]

It has been documented that the late models, adjustment intervals are quite long, something in the order of 15K, then 90K. Either that or 30K, then 90K. The valvetrain design has not changes from the 3.0 to the 3.2 liter engine. The only difference being slightly bigger valves. The first adjustment is important due to break-in and engine wear that occurs early on. AFter that, it is pretty stable and doesn't move much. The 91 manual does call for adjustments at every 15K, but Honda learned from that and extended their recommended intervals on late models.

This sounds like sheer speculation on your part. Sorry, I don't base my car's maintenance on someone else's conjecture.

Granted, if you are doing track events every weekend, that is a different story. But for normal driving with a few track events every year, after the first adjustment, the next one should follow at 90K.

Not according to me. Not according to all the expert mechanics who know our cars inside and out. If you want to neglect your car, by all means go for it! But don't go making blanket statements about what other people should do based on guesswork.

If you have actually done the valve adjustment yourself rather than pay the Master certified Acura mechanic to supposely adjust your already-in-spec valves, so you can have peace of mind every 15K miles, you will realize that those valves really do not move much, if at all.

That's not what Larry B has found. And I bet he's adjusted valves on at least ten times as many NSXs as you have.

 

[annointed]

That's not what Larry B has found. And I bet he's adjusted valves on at least ten times as many NSXs as you have.

Are you saying Larry B has adjusted valves every 15k miles on many NSXs? Or simply that he's adjusted the valves on many NSXs? There is a world of difference with regard to the point in question. I'd love to see data on a higher milage NSX showing the actual recorded valve clearances over its history, in regular 15k mile increments.

I think the original point was that if you want to save money, learn to check your valve clearances, and do so every 15k miles, and you will (purportedly) see little or no change between 15k and 90k. I'd love to hear from someone diligent enough to have done this. The original point was certainly not to "neglect" your NSX.

 

[Silver F16]

This sounds like sheer speculation on your part. Sorry, I don't base my car's maintenance on someone else's conjecture.

Your ignorance can be overcomed by doing a search or looking up a late Model owner's manual.

We can all find cases of someone saying you need frequent valve adjustment or someone saying that valve adjustments every 15K is a waste of time As seen in the bottom of this post.

http://www.nsxprime.com/forums/showthread.php?t=70087&highlight=valve+Adjustment+interval

Some of us feel better paying someone for the peace of mind. And that's ok. But if you did the adjustments yourself you can then draw your own conclusion. Then you would not have to based it on what someone says, including the mechanic who may want to make you feel good that your money was well spent.

There is a reason why Acura extended their valve adjustment intervals.

If you really want to know your car and how it wears, do the maintenace yourself. If you are not that mechanically inclined, then have someone you trust show you and guide you thru the process. Be there during the entire 3 hours when he does the adjustment and learn from it.

That way, you really know what happened first hand.

 

[Larry Bastanza]

mmm... seems many have decided what I said......LOL

OK, my comment was based on doing many valve adjustments on many different cars, and the fact that the majority of them are not correct for all 24 valves. I was not speculating about valve adjustment life per sa. Valve adjustment intervals have been relaxed over the years just like timing belt life has been extended. I personally think this is based on marketing decisions that are based on failures being minimal or non-existent.

Remember most NSX's average 5K miles year which put the valve adjustment interval at three years. I cannot speak to cars that I have seen multiple times every 15K miles, since the average NSX is not used in that way.

I have heard that 30K or valve noise was the new "in vogue" thought on this. I do not have the 1997+ manual here now, so I cannot comment if this is factory recommended.

Again, from my experience, only one NSX in the last three years I have seen had ALL 24 valves adjusted correctly. I just had a car with about 30K since the last valve adjustment and 5 valves were out, some loose, some tight. Unfortunately, I really do not know if there were set properly 30K miles ago.

Hope that clarifies things.

LarryB

 

[Hugh]

I think the reason Honda specifies short intervals is so the dealers can make money by charging for the work and not doing it. When I bought my '93 3 years ago it had 70,000 miles on it. I received copies of all the service records which showed that the previous owners paid for 2 valve jobs and all the other routine maintenance. After I bought the car I took it to Mike at MCA Motorsports who discovered the valve covers were never removed from the car and the thing still have the original fuel filter. When Mike checked the valves they were very close to spec and only required minimal adjustment.

Doesn't the NSX have "shim under bucket" type valves? Those hold their adjustments very well don't they?

Dealers suck.

 

[austrian type-R]

old thread but I can clarify that after doing like 20 engines. The valve adjustment is something you dont need to do every 15000 miles. Simply check it at each TB job and good.