Easiest Way to Look at Timing Belt?

[Bigfieroman]

Hey all, I just picked up a 2000 with just under 60k; supposedly the TB and WP were changed in 2021/1.5k miles ago, but I am suspicious because the serpentine belts appear to be original. What is the easiest way to get a peek at the timing belt? I figure it will be easy to tell, visually, if it has 1.5k or 60k on it. It looks like maybe pulling the front valve cover is the easiest way?

 

[Bigfieroman]

I forgot to mention, I do have an endoscope, so if there is any opening larger than ~0.25", I can get a look at the belt...I just didn't see any obvious openings/inspection ports.

 

[Honcho]

Welcome to NSX Prime! Congrats on the pickup- the 2000 year model is a sweet spot for NSX fans- it has all the updated stuff but keeps the pop-ups. You should post a hello and intro thread in the new owners forum!

Believe it or not, there's no real way to tell visually if a TB is new or not. I've removed belts with over 120,000 miles and they look new, but are obviously at the end of their service life. The NSX timing belt is very, very well made. The only real way to get a look at it is to remove the valve covers, but you'll only see this.


You need to remove the front covers to really see the belt:



Honestly, it's not going to tell you a lot. It's probably a better use of your time to do some sleuthing and figure out the shop that did the work and talk to them.

If you are looking at the belt, you want to look at the rubber teeth and see if the texture is rough. Rough means a new belt. Smooth means a loose new belt or older belt- it's not an exact science lol.

 

[Bigfieroman]

Thank you for the information. I guess I figured that I would probably be unable to read any writing on the smooth side of the belt or perhaps that it would be yellowed if it were original, and such a new replacement would still be white/legible. I am pursuing the info on the shop that supposedly did it as well, but I felt that a belt-and-suspenders approach was best for such an important question.

I will post a hello/intro soon, I got home from picking it up literally 16 hours ago at this point, lol. I am just anxious to know if I am taking a risk every time I turn the key or not.

 

[Honcho]

Thank you for the information. I guess I figured that I would probably be unable to read any writing on the smooth side of the belt or perhaps that it would be yellowed if it were original, and such a new replacement would still be white/legible. I am pursuing the info on the shop that supposedly did it as well, but I felt that a belt-and-suspenders approach was best for such an important question.

I will post a hello/intro soon, I got home from picking it up literally 16 hours ago at this point, lol. I am just anxious to know if I am taking a risk every time I turn the key or not.

Don't worry too much- it's not a time bomb like in other cars. I've actually never seen a case of the belt snapping on the NSX, and I've seen some really sketchy, floppy 30+ year old belts pulled out of the car. Your main concern actually should be the belt slipping, which happens all the time. We see many NSXs that are off by a tooth- this indicates either age or improper tensioning when the belt was installed. Factory-installed belts do not slip until they are quite old. Dealer installed belts seem to slip more often. One way to check this for peace of mind is to connect a vacuum gauge to the PCV nipple on top of the intake manifold. If the needle is "dancing" at idle, you're off by at least 1 tooth. If the needle is steady, the belt is timed properly. They way you slip a tooth is by stabbing the throttle quickly, like when you are tracking the car. Basically, if the belt is old and the teeth are smoothed out (or if it was sloppily tensioned by the dealership monkey), it can slip over the cam gear teeth under sudden acceleration.

 

[Bigfieroman]

Once again, thank you for the information!

 

[Bigfieroman]

Ok, I am pulling the valve covers today, but in looking through the carfax and calling the shops at which the car was serviced in the last few years, I am 95% sure that the timing belt is original.

As I prepare to undertake this job, I have been researching here pretty extensively. I am going to replace the cam caps with aluminum ones (Skunk2, not a great brand, but I am just going to slather them with Hondabond rather than rely on the o-rings), I am going to set the valve clearances, replace the timing belt/waterpump/gaskets with OEM Honda parts, replace the timing belt tensioner with the CRF locking unit, replace the serpentine belts, and install an ATI Superdamper. I am under the impression that I don't need to worry about the LMAs because my car is a 2000.

Am I missing anything from my list of "while I'm in there" scope-creep?

 

[Bigfieroman]

Yeah...this car has only done 4k miles in the last 10 years. Even if this isn't the original timing belt, it certainly has more than 4k on it, meaning it is aged out. Fun stuff.

 

[Bigfieroman]

It looks like at least one tutorial recommends doing the front crank seal during this job. I usually don't mess with front main/rear main seals unless they are leaking - the car has under 60k miles. Should I change it?

 

[Spoolinfool]

Yes change the crankshaft seal while you are there. You'll have easy access and its really a 5 minute job. Do all the seals including the camshaft seals and the orings underneath the cam caps closest to the belt. If you do that youll only really have 1 other seal when you do the clutch which is the rear main seal. Take your time and mark the old belt as well as remark (factory marks are faded by now and hard to see) the marks on the cam gears and anywhere else that would make it easier for you to identify timing marks when your done.

 

[Bigfieroman]

Yes change the crankshaft seal while you are there. You'll have easy access and its really a 5 minute job. Do all the seals including the camshaft seals and the orings underneath the cam caps closest to the belt. If you do that youll only really have 1 other seal when you do the clutch which is the rear main seal. Take your time and mark the old belt as well as remark (factory marks are faded by now and hard to see) the marks on the cam gears and anywhere else that would make it easier for you to identify timing marks when your done.

I am having trouble finding the o-ring under the cam caps...?

I am using the diagrams here:

Cylinder Head (Front) - 2000 Acura NSX 2 Door NSX-T KA 6MT

Shop in the parts listing - 2000 Acura NSX 2 Door NSX-T KA 6MT Cylinder Head (Front). Discounted prices and Hassle-Free Return on genuine Acura parts.

www.acurapartswarehouse.com

 

[Bigfieroman]

Ohh, looks like they are 91302-GE0-000?

 

[Spoolinfool]

Yeah you'll need 3 of them. One will be used on each side head and 1 last one will be for the oil dipstick tube.

 

[drew]

Does the rubber feel grippy or dry?

 

[Spoolinfool]

Replace the 2 water hoses for the oil cooler and replace the 3 orings on it. 2 orings sandwiched between the oil cooler and oil cooler pedestal and one figure 8 shaped oring between the oil pedestal and the block. They may look fine but they are default heat exchangers and end up being pretty worn out due to the heat that goes through them.

 

[Honcho]

Ohh, looks like they are 91302-GE0-000?

Yes, that's correct.

I would avoid the aluminum cam caps- most of the designs out there tend to leak because the O-rings they use to seal aren't sufficient enough to expand and contract through the years of the engine's heating and cooling cycles. Most people who install them don't keep their NSX long enough to see the leaks happen. The rubber caps- if installed correctly- will last the entire TB service interval without leaking. I use Hondabond HT, although I was originally taught to install them dry. My method looks like this:



The three "ribs" seal the splash oil and flex as the head expands and contracts from the heat cycles. Placing the Hondabond after the third rib provides a final barrier for any oil that makes its way past the ribs as the caps age and harden. I also put another thin layer of HB on the outside of the caps as well.



You should also replace the cam seals on the other end of the engine. Make sure to seat them evenly- if they are set even a little bit crooked, you will get oil leaks. I use a micrometer depth gauge to make sure the seal is the same distance from the housing all the way around.

I recommend replacing the crank seal, since it is a time and not just miles interval. The part is cheap and will likely last the rest of the life of the car. Same with the crank pulley. If you don't replace it, at least install a shield from Cedar Ridge or T3TEC so if your pulley grenades, it won't kill your engine.

I also recommend replacing the front cover (the metal ones) bushings, as the ones in there are probably hard and crusty. Same goes for the front timing cover gaskets- there are several of them. I don't recommend re-using 24-year old rubber anywhere on the engine.

@Spoolinfool is right and you should try to replace the oil cooler hoses and pedestal gasket while you have access. They are a royal pain and best to change them out before they fail. NSX engines have been lost due to these particular hoses. Make sure to set the hose clamps in an orientation where the tabs won't rub the hose above and are easy to reach if you need to get to them next time. I hate it when lazy dealer techs put the tabs between the hose and the engine block!

Since you are draining the coolant and replacing the water pump, it might be a good time to think about doing the rest of the hoses. It's also a good time to check your radiator for leaks. The OEM Honda radiator lasts about 20 years before the plastic tanks start to separate from the aluminum core.

Remember, the most important thing to do on this job is make sure all surfaces are surgically clean before applying any Hondabond or rubber gaskets. The number 1 cause of oil leaks on the NSX engine is sloppy installs from a failure to clean, usually because dealer techs are rushing and just wipe everything down with a dirty shop rag. Wipe everything with an acetone soaked microfiber cloth.

BTW, your timing belt is original. I can tell from the markings.

 

[Spoolinfool]

Another option for the cam cap end seal is part number 12513-P72-003. This is for the honda b18c engine but it is also used in the honda b16a and b18c5 which also use the exact cam cap seal as the Nsx. The only difference with this version is you can remove them from the outside with a flat head screw driver without removing the cam caps. They install just pushing a new one in and the clips retain them there.

 

[Bigfieroman]

Another option for the cam cap end seal is part number 12513-P72-003. This is for the honda b18c engine but it is also used in the honda b16a and b18c5 which also use the exact cam cap seal as the Nsx. The only difference with this version is you can remove them from the outside with a flat head screw driver without removing the cam caps. They install just pushing a new one in and the clips retain them there.

Ohh neat! I am definitely going this route. Thank you for the option!

 

[Bigfieroman]

I also recommend replacing the front cover (the metal ones) bushings, as the ones in there are probably hard and crusty.

I am planning on doing everything you recommended, except I do like the idea of the replaceable cam caps that @Spoolinfool mentioned. I don't care if they leak every 10k, I can just pop in new ones vs. having to remove the cams again.

However, I don't understand this quote above...what front cover? The metal bushing pushed into the center timing cover?

The parts diagrams don't really show those as a separate part.

Timing Belt Cover - 2000 Acura NSX 2 Door NSX-T KA 6MT

Shop in the parts listing - 2000 Acura NSX 2 Door NSX-T KA 6MT Timing Belt Cover. Discounted prices and Hassle-Free Return on genuine Acura parts.

www.acurapartswarehouse.com

 

[Spoolinfool]

Buy 19200-PR7-305 and it will come with a new lower timing cover with package. I think Honcho is referring to the front valve cover rubber/metal grommets maybe.

 

[Bigfieroman]

Buy 19200-PR7-305 and it will come with a new lower timing cover with package. I think Honcho is referring to the front valve cover rubber/metal grommets maybe.

I already ordered the water pump from Amayama...Do I need a new lower timing cover? I know they changed the design because of the weep hole location, but when did that happen? I have not gotten into my timing cover yet, but I guess I just assumed a 2000 had the later design timing cover.

Regarding the valve cover grommets, mine are actually in very nice shape. That being said, I bought 2X 12030-PR7-010 valve cover gasket sets which come with new grommets, as far as I can tell.

 

[Spoolinfool]

You dont need the timing cover since you have the updated cover and your right the valve cover kit does include those grommets.It a good time to send the valve covers out to powder coat if they are flaky.