[SFI] It seems that the last time that dealer repaired that problem on another 91, they replaced the entire VTEC solonoid including both gaskets (as one is inside the case). After the responses from the group, I questioned weather a better way to go might be to replace only the gaskets (listed as a 'filter' due to the integrated screen within the gasket) as opposed to the entire $345.00 assembly.
They did as I asked, and the TOTAL bill was for $95.00. My daughter and I just took a 600 mile run through the Blue Ridge Mountains, and the leak seems to be gone. Thanks to the list for saving me at least $300.00.
[CA] If you have a small oil leak and cant seem to find the source, check out the VTEC spool valve gasket, according to the dealer, they are infamous on the NSX, mine was on the rear bank of cylinders and slowly leaking onto the exhaust. If you are good terms with your dealer, the cost is about 100 or so including labour, prices may vary of course. NSX back in my garage 100% operational.
Coil Corrosion / Engine Sputtering
A recurring engine sputtering problem, even on a very low mile car, can be caused by coil corrosion. Intermittently, when accelerating in any gear there is a loss of power, feeling like fuel starvation. It cuts out then back in, then out then back in. It's most noticeable during hard acceleration. This happens with TCS and ABS on or off, the engine warmed up, no "Ckeck Engine" light coming on. In 2000/2001
[CA] If it is in fact damaged, I would take this to the dealer as well, and say "What the hell is this?" and show them. Mine and others had a small visible bit of corrosion, that was easily wiped off (ok, I used a little baking soda and a toothbrush because I am seriously anal). The dialectric grease is put inside of the spark plug boot on a standard car with spark plug wires, as my Integra GS-R is, wouldnt hurt on the distributor/coil terminals either, this prevents some wierd problems sometimes as well. As for the NSX, apply a small (doesn't matter, I like to be neat) amount inside the coil where the spark plug will interface, this grease conducts very well!
Someone else asked how the silver coil covers should be put back on. I like the rubber seal on the inside (intake) side of the coils, to keep water from dripping inside the coil cavities. This only makes common sense to me, I dont know why there isnt a rubber seal on each side. Maybe the coils need to "breath" somewhat.
You may also want to pull a spark plug to determine what it looks like corrosion wise. Corrsosion and electricity dont mix very well. Be very careful reinstalling the plug as the head as well as the rest of the engine is mostly aluminum, and can crossthread and strip easily. I am not a muscle head, and have stripped literally hundreds. (hint use a small socket driver where possible, not as much torque leverege as a larger driver).
If You Flip Your Car...
[KJ] When you turn a car over, the oil in the pan seeps past the rings into the combustion chambers, and then through any open intake valves (and, to a lesser extent in the NSX, exhaust valves) into the manifold and intake plumbing. When you turn the car right-side up, the intake track has lots of oil in it, and some of this oil could easily end up on the ground.
This also means that you should pull the plugs and make sure the oil is pumped out before you attempt to start an engine that has been inverted for more than a few seconds. Otherwise the compression stroke could break something when the engine tries to compress oil instead of air.