Major service suggestions on 91

I am due for my timing belt and water pump this summers and am considering having the engine dropped (tech was able to service it last time without pulling it) and looking for suggestions on what to have done while everything is easily accessible. Here's the list of what I am looking at so far.

1. Clutch - I've put over 40,000 miles on the car in during my ownership and I know the previous owner had it done not very long before my purchase.
2. Valve adj
3. Motor mounts swapped with science of speed mounts? Thoughts?
4. Timing belt/water pump - along with main pulley
5. Cam gasket? Thoughts? I've had a nagging oil seepage issue for a number of years coming down around the oil pan - I thought it may be a pan gasket issue but it seems to be coming from further up, service tech said cam gasket (at least I think that's what he said, I didn't write it down when we were talking).
6. I have the ABS rebuild kit provided by another member here, looking at that as well along with brake bleed.
7. Transmission fluid - done with a clutch I assume?
8. Science of speed coolant hose kit

Any other thoughts on things to do while he's got full access?

I'm guessing two things at this point.... #1 It'll cost a pretty penny and #2 it'll set the car up for a good number of years to enjoy hopefully trouble free.

well if you ever go to the track the billet oil pump gears and a baffled pan might be nice.Also if you want to retain the oe clutch but want a quicker/more exotic feel try this http://www.nsxprime.com/forum/showt...buy-feeler-thread-Tilton-Engineering-Flywheel

If I recall, the previous owner said I had a lightweight flywheel installed in my car from dali and after driving an oem flywheeled NSX, I think that may be the case. I have no proof but I believe John Vasos installed it, but I'm betting they'd have no record on file as I've had the car for abotu 10 years now and my current Acura dealer purges after 6 or so years. What are the chances I could reuse my current flywheel vs have to redo everything? I'll be using Bill at Fox Acura in Grand Rapids for this service and he said he's comfortable using aftermarket stuff, just would need to know ahead of time what all needs to be done.

- - - Updated - - -

Point me in the correct direction if that Johnathan posts his group buy info. I'll touch base with bill to see what his thoughts are on what I should do as well.

I just removed one of my spool valves for gasket replace (other will follow).
These looked like they were causing leaks in their area.
I was able to remove the rear because the car is off the ground and exhaust is off.
Gasket was hard - not pliable.
My car is a 94.
My pan gasket is getting replaced at the same time.
(And the baffle getting installed per suggestion) ...
There are also some o-rings associated with the oil pressure sensor for valve timing
(green sensor one sticking out of the spool valve)
And two associated with the oil pressure on the front spool valve.
I am doing these also.

This is what I ordered:
1 91302-PR7-A00 O-RING (13.8X1.9)
3 91319-PR3-003 O-RING (13X1.5) (ARAI)
2 15825-PR3-005 FILTER ASSY., SPOOL VALVE (Gasket)
2 36172-PR3-005 FILTER ASSY., SOLENOID
I also ordered spool valve bolts - 6 each of 95701-06030-08 and 95701-06018-08

Good luck

Hose replacement might be another consideration as long as your doing the added service.

comquat1 said:

Any other thoughts on things to do while he's got full access?

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You don't mention the fluids other than transmission fluid, but they should be done. They would probably flush the coolant anyway, when doing the water pump and hoses. Do an engine oil change (probably implied, but worth mentioning). And brake fluid.

comquat1 said:

I believe John Vasos installed it, but I'm betting they'd have no record on file as I've had the car for abotu 10 years now and my current Acura dealer purges after 6 or so years.

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I'll take that bet. Besides, why not call and find out? What have you got to lose by trying?

Vanishing Point said:

Hose replacement might be another consideration as long as your doing the added service.

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See #8 in his list.

certainly do the other belts besides the timing belt

I did the spool valves myself a year or so ago thinking that may eliminate the oil seepage, but it hasn't to know avail, hence looking at the cam gaskets (or whatever that service write said).

Coolant will be done with the timing belt and assy belts as well.

Brake bleed I will most likely do myself when I do the rotors and pads sometime this year.

Also, who's the best deal for online parts at this point? I've been up front with my dealer that they've unfortunately never been competitive in the past and I will work with them if they can get their parts prices in line, but I am going to do my due diligence in shopping around for this list that I'm going to need.

1. Clutch - I've put over 40,000 miles on the car in during my ownership and I know the previous owner had it done not very long before my purchase.
Clutches depend on driving style. I have seen them go at 25,000 and others last until 100,000+. At a minimum, maybe have them pull the clutch and measure how much material is left on the discs? That should give you an idea of how much time you have left and also how your driving style affects the life. Then, you can choose to replace it or wait.
2. Valve adj
This is typically done with the TB replacement, since most good techs will adjust the valves all the way out for safety before setting the timing belt.
3. Motor mounts swapped with science of speed mounts? Thoughts?
Believe it or not, this is not a high wear item. One of our respected local techs has said out of the hundreds of NSXs he has serviced, only one had bad mounts. I would only replace them if they are visibly damaged. Look for cracks or splits in the rubber webbing. That said, I have stockpiled new front and rear mounts for a rainy day.
4. Timing belt/water pump - along with main pulley
Definitely. Crank pulley should be done as well, even though it is not in the service manual.
5. Cam gasket? Thoughts? I've had a nagging oil seepage issue for a number of years coming down around the oil pan - I thought it may be a pan gasket issue but it seems to be coming from further up, service tech said cam gasket (at least I think that's what he said, I didn't write it down when we were talking).
Depending on driving style and climate, most of the oil-sealing rubber gaskets on the NSX will last 7-15 years. That is either one or two timing belt intervals. Most people replace them all at every TB service to save labor and oil leak headaches. You want to do valve cover, oil cooler, oil pressure sender, cam plugs, spool valves, and the dipstick. Might also be time to inspect the rocker shaft plugs for leaks and replace the washers. Parts are cheap but a dry engine is priceless. I would also consider cam seals and rear main seal.
6. I have the ABS rebuild kit provided by another member here, looking at that as well along with brake bleed.
ABS service is part of the 60k mile service. It involves replacing the high and low pressure lines and flushing the system. A full rebuild might also be wise given Warren's work on this issue, but I just had the basic service done and will just replace with the NA2 modern system when it finally breaks.
7. Transmission fluid - done with a clutch I assume?
Yes, but you should change this every 2-3 years regardless. Use the Honda White Cap fluid.
8. Science of speed coolant hose kit
Definitely worth doing now to save labor. You also should replace the thermostat, coolant bottle and cap. If your radiator is original, I would consider replacing it as well.

Any other thoughts on things to do while he's got full access?
Updated LMA. Your 1991 LMA eventually will fail. Might as well change them out. I used the kit from SOS. Also, consider cleaning and refurbing your intake manifold, FITV, EACV and throttle body. Also send your fuel injectors out to RC Engineering in California. It will make a big difference.

I'm guessing two things at this point.... #1 It'll cost a pretty penny and #2 it'll set the car up for a good number of years to enjoy hopefully trouble free.[/QUOTE]

Honcho said:

1. Clutch - I've put over 40,000 miles on the car in during my ownership and I know the previous owner had it done not very long before my purchase.
Clutches depend on driving style. I have seen them go at 25,000 and others last until 100,000+. At a minimum, maybe have them pull the clutch and measure how much material is left on the discs? That should give you an idea of how much time you have left and also how your driving style affects the life. Then, you can choose to replace it or wait.
2. Valve adj
This is typically done with the TB replacement, since most good techs will adjust the valves all the way out for safety before setting the timing belt.
3. Motor mounts swapped with science of speed mounts? Thoughts?
Believe it or not, this is not a high wear item. One of our respected local techs has said out of the hundreds of NSXs he has serviced, only one had bad mounts. I would only replace them if they are visibly damaged. Look for cracks or splits in the rubber webbing. That said, I have stockpiled new front and rear mounts for a rainy day.
4. Timing belt/water pump - along with main pulley
Definitely. Crank pulley should be done as well, even though it is not in the service manual.
5. Cam gasket? Thoughts? I've had a nagging oil seepage issue for a number of years coming down around the oil pan - I thought it may be a pan gasket issue but it seems to be coming from further up, service tech said cam gasket (at least I think that's what he said, I didn't write it down when we were talking).
Depending on driving style and climate, most of the oil-sealing rubber gaskets on the NSX will last 7-15 years. That is either one or two timing belt intervals. Most people replace them all at every TB service to save labor and oil leak headaches. You want to do valve cover, oil cooler, oil pressure sender, cam plugs, spool valves, and the dipstick. Might also be time to inspect the rocker shaft plugs for leaks and replace the washers. Parts are cheap but a dry engine is priceless. I would also consider cam seals and rear main seal.
6. I have the ABS rebuild kit provided by another member here, looking at that as well along with brake bleed.
ABS service is part of the 60k mile service. It involves replacing the high and low pressure lines and flushing the system. A full rebuild might also be wise given Warren's work on this issue, but I just had the basic service done and will just replace with the NA2 modern system when it finally breaks.
7. Transmission fluid - done with a clutch I assume?
Yes, but you should change this every 2-3 years regardless. Use the Honda White Cap fluid.
8. Science of speed coolant hose kit
Definitely worth doing now to save labor. You also should replace the thermostat, coolant bottle and cap. If your radiator is original, I would consider replacing it as well.

Any other thoughts on things to do while he's got full access?
Updated LMA. Your 1991 LMA eventually will fail. Might as well change them out. I used the kit from SOS. Also, consider cleaning and refurbing your intake manifold, FITV, EACV and throttle body. Also send your fuel injectors out to RC Engineering in California. It will make a big difference.

I'm guessing two things at this point.... #1 It'll cost a pretty penny and #2 it'll set the car up for a good number of years to enjoy hopefully trouble free.

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[/QUOTE]


Thought I new all the shorthand terms but what are the following.

LMA
FITV
EACV


Also, what's the story with RC Engineering and fuel injectors? I want to be somewhat careful and not be the guy who's got his car tying up a bay for 2-3 weeks because I'm taking parts and sending them out to third parties for whatever. I feel like enough of a heel providing my own parts.

Do what HONCHO says in his post. It won't be cheap but he helped me out restoring my 91 NSX. It runs the balls now and I followed his feedback as I was new to the car a year ago. Actually, just realized that today is my 1 year ownership anniversary (a tear comes to my eye).

Fluids - Do them ALL now
TB & h2o pump - very important.
Motor Mounts - I agree with Honcho. Unless they are damaged, save your self the $$
Clutch - I have to do mine soon as well (55K) but have been driving it for a few hundred miles with 5-10% left.

my restoration hit $9k. But I love my car so much. These things are amazing (and mine really needs new paint and a few dings fixed).

I hope my son enjoys public school now

comquat1 said:

Thought I new all the shorthand terms but what are the following.

LMA
FITV
EACV


Also, what's the story with RC Engineering and fuel injectors? I want to be somewhat careful and not be the guy who's got his car tying up a bay for 2-3 weeks because I'm taking parts and sending them out to third parties for whatever. I feel like enough of a heel providing my own parts.

Click to expand...

LMA = Lost Motion Assembly. These are small hydraulic springs that keep the VTEC rocker arm under tension when the car is not in VTEC. They prevent rocker arm wear and noise and are a key part of the valve train for the NSX. The problem is Honda over-engineered the LMA for the NSX. Our original LMA units are essentially a spring inside a metal cylinder. Over time, they wear into the sleeve and start to bind. Eventually, they will fail and your engine will start to have a rattle as the VTEC rockers flap around loose. LarryB was kind enough to bring some bad ones to the 2012 NSXPO tech session and demonstrated to us how they go bad. That was enough to convince me to replace them during my major service. I used the SOS kit here. As you can see, these are a simple spring- they got rid of the cylinder. The SOS kit uses the S2000 springs plus a spacer that makes them fit the NSX. However, Honda apparently corrected their error and you can also by the new spring-style for the NSX directly from Honda. We discovered 3 of my LMAs were binding when we replaced them at ~90,000 miles. You should know it is extra labor to do these, since the cams must come out.

FITV = Fast Idle Thermo Valve. This unit helps with your cold idle by raising the rpm to prevent stalling. It should be cleaned to prevent cold starting and idle problems.

EACV = Electronic Air Control Valve. This unit also helps manage your NSX idle under a variety of conditions set by the ECU. I can almost guarantee yours is caked solid with black soot. It should be cleaned and/or the screen replaced.

You can reference my thread here for more information: http://www.nsxprime.com/forum/showthread.php/178307-Intake-Manifold-Overhaul

As for the injectors, take a look at my report in the above thread. I use Techron religiously at every oil change and 2 of my injectors still were dripping. Turn around time was only 24 hours and I basically have a brand new intake/injector setup.

jaybrown2003 said:

Do what HONCHO says in his post. It won't be cheap but he helped me out restoring my 91 NSX. It runs the balls now and I followed his feedback as I was new to the car a year ago. Actually, just realized that today is my 1 year ownership anniversary (a tear comes to my eye).

Fluids - Do them ALL now
TB & h2o pump - very important.
Motor Mounts - I agree with Honcho. Unless they are damaged, save your self the $$
Clutch - I have to do mine soon as well (55K) but have been driving it for a few hundred miles with 5-10% left.

my restoration hit $9k. But I love my car so much. These things are amazing (and mine really needs new paint and a few dings fixed).

I hope my son enjoys public school now

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Thanks! Glad to hear she's running strong.

Slave cylinder and hose since your right there. Rear main seal and axle seals since your right there. Check the CV boots very closely since your there. Especially the right inner one under the exhaust.

comquat1 said:

who's the best deal for online parts at this point?

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Tim at Acura of Peoria.

Thanks Ken for the info!

I had a nice long talk with John Vasos today after I had emailed him about whether my car had a lightweight flywheel in it and it was a very productive talk. Long story short, Nothing against anyone here, but I trust his advice and he had some valid points over what I was looking to do vs actually should do.

I'm hoping in some way that I will be able to have him get my car via a meet up this summer and have Acura of Brookfield go through it.

At this point is looks like at a minimum I'm for sure going to do the following.

TB/WP/Crank pulley
All coolant hoses
tranny fluid
ABS rebuild kit
Have my clutch condition at least inspected


Versus what I was planning on doing I believe John saved me well into four figures. I'm really hoping he and I will find a way to meet up to get him my car.

Another tidbit that was shared and interesting is ever since I owned my car I thought it revved quite readily vs. an NSX that I experienced a number of years ago that had not been driven much on the track. The previous owner of my car tracked my car quite a bit. I honestly thought I had a lightweight flywheel on my car because the difference was so pronounced. John explained that an engine that has been cycled like mine was on the track as much as mine was will feel quite different from one that served daily driving duties on the street. I never heard that before, but made sense to me. I can't imagine my car feeling like a street driven vehicle and it sounds like I got an added experience bonus by buying the car I did.

I'm sure John's recommendations significantly reduce the cost of the service. Honcho's suggestions are based off the services recommended by Kaz from the NSX Club of Britain. Kaz is one of the engineers who originally designed the NSX, he was trained to carry out the "NSX refresh" program Honda offers in Japan, and before all that he was on Honda's Formula 1 team. Kaz currently lives in England, where he is willing to service the cars he helped develop and he documents his work. I'm sure John Vasos is good, but have a look at Kaz's blog: http://www.nsxcb.co.uk/entry.php?1083-Eng-Refresh-Health-Check-Preparation-02. On the right hand side of the page you can see the "Blog Categories". It's interesting to see the condition of used NSXs and how they should be serviced to get them back into tip top shape.

Regarding the flywheel: how quickly the engine can spin up the flywheel is simply determined by how much torque the engine produces and how heavy the flywheel is (more specifically, its moment of inertia). If a car is only driven slowly for short distances in stop and go conditions, stuff can happen like deposits building up on the back of the intake valves which may reduce power. Did you notice that the other NSX you drove didn't rev as quickly AND had less power or did it just not rev as quickly?

If you get the car on a lift, you can see a bit of the flywheel from below. Does anyone know whether you can see enough without unbolting anything to determine whether the flywheel is stock or aftermarket?

Edit: I recently replaced the clutch case cover on my NSX (part#1 here), which is held in place by three screws and can be removed in about a minute if the car is up on a lift. If I remember correctly (and I'm not sure I do), you have a good view of the flywheel if you remove that.

greenberet said:

I'm sure John's recommendations significantly reduce the cost of the service. Honcho's suggestions are based off the services recommended by Kaz from the NSX Club of Britain. Kaz is one of the engineers who originally designed the NSX, he was trained to carry out the "NSX refresh" program Honda offers in Japan, and before all that he was on Honda's Formula 1 team. Kaz currently lives in England, where he is willing to service the cars he helped develop and he documents his work. I'm sure John Vasos is good, but have a look at Kaz's blog: http://www.nsxcb.co.uk/entry.php?1083-Eng-Refresh-Health-Check-Preparation-02. On the right hand side of the page you can see the "Blog Categories". It's interesting to see the condition of used NSXs and how they should be serviced to get them back into tip top shape.

Regarding the flywheel: how quickly the engine can spin up the flywheel is simply determined by how much torque the engine produces and how heavy the flywheel is (more specifically, its moment of inertia). If a car is only driven slowly for short distances in stop and go conditions, stuff can happen like deposits building up on the back of the intake valves which may reduce power. Did you notice that the other NSX you drove didn't rev as quickly AND had less power or did it just not rev as quickly?

If you get the car on a lift, you can see a bit of the flywheel from below. Does anyone know whether you can see enough without unbolting anything to determine whether the flywheel is stock or aftermarket?

Edit: I recently replaced the clutch case cover on my NSX (part#1 here), which is held in place by three screws and can be removed in about a minute if the car is up on a lift. If I remember correctly (and I'm not sure I do), you have a good view of the flywheel if you remove that.

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All good info to take a look at.

Talked with my mechanic today and one thing I'm dealing with is oil seepage that seems to be coming from the oil pan gasket. In changing this it's more difficult since I have a set of one piece headers. The mechanic is leaning towards wanting to drop the engine because of this. Does this seem right? His concern is getting a new gasket on once he loosens all the nuts. Anyone else remove their header with the engine in place? I'm looking at about another $500 to do the full engine drop in order to do this and obviously would rather not pay it if I don't have to.

It is realtively easy to pull the front header if you have a lift. Remove the front beam completely and you will have plenty of access.

Now that you say this I remember that from a couple years ago when I was looking at doing this myself. I'll double check with the mechanic. We didn't get the car up on a lift when I stopped in, if we did that it probably would have jogged my memory....

comquat1 said:

Now that you say this I remember that from a couple years ago when I was looking at doing this myself. I'll double check with the mechanic. We didn't get the car up on a lift when I stopped in, if we did that it probably would have jogged my memory....

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I did it once on my back with jackstands. I'll never do that again. Lift only. Also, make sure to check with LarryB for the correct technique for tightening the oil pan bolts. If not done correctly, you'll get a leak fairly quickly.

Honcho said:

...make sure to check with LarryB for the correct technique for tightening the oil pan bolts. If not done correctly, you'll get a leak fairly quickly.

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+1. The oil pan nuts and bolts should not be torqued as tight as the Service Manual recommends. If they are torqued too much, the gasket will get squished out and will become wider than the oil pan. The gasket has holes in it for the studs and bolts to pass through and as the gasket gets squished, those holes get elongated, creating an oil leak. From memory, the oil pan nuts and bolts should be torqued to the point that the gasket just doesn't get squished out wider than the pan and that torque level is below what the Service Manual recommends. LarryB would be a great person to ask but it would also be interesting what your mechanic's own plan of attack would be.

comquat1 said:

Anyone else remove their header with the engine in place?

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I did, too. With the car on jack stands in my garage using regular hand tools. While the headers were off, I also replaced the oil pan gasket because the last mechanic who did that tightened the nuts and bolts too far, creating an oil leak. In his defense, the mechanic at the dealership probably just followed the Service Manual. But it demonstrated that he was not much of an expert when it came to NSXs.

The MAIN one to consider is the Crankshaft Pulley, and maybe fitting a pulley shield for added protection.
i ignored this and footed a decent bill from a crank pulley failure.