AP1 Valve adjustment at 38K Miles
 

Hi All,

I bought my single owner 2001 in 2015 with 19K miles on it, now it has 38K miles. The car had been well taken care of, but of course I changed all the fluids and did some other maintenance tasks when I first bought it.

One thing I didn't do was a valve check/adjustment. I knew I should do it, but I resisted because I knew that the engine had not been opened up since it was built at the factory and I didn't want to start any oil leaks or somehow screw up a good thing. However, finally I read too many stories about how important it was to check valve clearances, although I gather that is mostly an AP2 DBW issue.

So I finally did it and I'm happy to report that I didn't have to adjust a single valve. All the clearances were on the looser side of the spec (0.010 to 0.011 exhaust, 0.008 to 0.010 Intake), and most importantly, they were all consistent. I didn't measure some that where closer to tight and some that were closer to loose, they all felt the same.

Other good news is that the inside of the valve cover and the head look very clean !!

https://cimg0.ibsrv.net/gimg/www.s2k...cd018bd080.jpg


The bad news, or at least what made it all worth my time was how loose the spark plugs were. Wowza, some of them were little more than finger tight ! I'm really glad I got that taken care of before there was trouble. I do remember reading somewhere that loose spark plugs were a problem in the past, but it really didn't register with me. I replaced the plugs and torqued them to 21 ft/lbs.

I was quite surprised at how worn the old plugs were at 38K miles, here is old vs new, notice how much of the electrode is worn away on the old plug ?

https://cimg3.ibsrv.net/gimg/www.s2k...d9f73948b5.jpg

I sort of feel that it runs smoother and pulls a little harder with the new plugs, but I've felt that way after washing and waxing it before, so probably just placebo :)

So, now I am confident that all is right with my S2000, and I don't plan on check valve clearances for a long time to come.

Mine shat a plug out and fooked my engine !!
Good call :thumbup:

my factory plugs were toast at 50k miles, the center electrode was heavily eroded like yours and the gap was out of spec due to it. Good call on replacing them.

It's a great, fun service to DIY that's for sure. Daunting at first but when you follow the tried and true instructions many others have, all works out well in the end. It's also good practice to replace your plug tube seals (and VC gasket if need be) because if they're hard they will let oil into the coil packs' chambers and that will burn out your coils prematurely leading to misfires. Probably not the case with yours based on mileage but something to keep in mind as the miles rack up.

Good call on the plugs. Sucks that they were loose in the first place! I love NGK Iridium BKR8EIX plugs. Great for boost but they definitely yield a performance benefit in NA mode as well. They're a step up from the stock PFR7's

I believe that 8 is a step colder. If that is what you mean by "up," from stock heat range :)

https://cimg3.ibsrv.net/gimg/www.s2k...c479e348ff.jpg

I'm curious (as usual :) ).

1. Would loose spark plugs contribute to the poor condition of those removed from the engine?

2. What "feature or benefit" is there in deviating from the OEM plugs in a road car?

-- Chuck

1. Probably not. The plugs were not tight enough to not eventually come loose, with devastating consequences. But probably not loose enough to cause compression leak and lean conditions, which is what destroys the plugs when they do become too loose.

2. If you mean a NA engine, usually none. Colder plugs are less prone to detonation. If you were running lower octane fuel, or had higher cylinder pressures due to boost, colder plug is a benefit. If you are stock motor, running proper fuel, and your ecu isn't pulling ignition advance due to knock sensor hits, a colder plug won't do anything.

That is assuming the stock plugs specified for the motor, and the octane specified, indeed result in ECU not having to pull ignition on a regular basis. Maybe there is something I don't know, and this scenario is something that happens with our cars, so colder plugs would indeed help. Curious to know since this isn't something I've heard about before.

I believe the Honda maintenance schedule calls for replacing the plugs based on age as well as miles. Anyone know why age degrades the plugs? I replaced the original plugs on my 02 a couple of years ago when it had just 20K mile or so. I swear the new plugs made noticeable difference. Might have been a placebo effect. But I don't think so.

That is what I mean :)

It's in your owner's manual, no need to guess! :) 2006 and later cars with the Maintenance Minder can download the 2005 manual which is available from Honda on line. Download the appropriate manual regardless and keep it on your computer. These are searchable PDFs which can get you information quickly. Same for the 2000 page service manual.

Honda specifies a spark plug replacement at 105,000 miles (168,000km). This would be at the same time a valve inspection (adjustment). No time limit. An earlier valve clearance check is highly recommended by experts here, especially the DBW cars. I last checked my valves 4 years ago at 40,000 miles and pulled the plugs to make rotating the engine to TDC on the cylinders easier. Plugs were out anyway so I just put in new ones. Easy peasy. ;) Plugs looked fine at 9 years. This task is on my maintenance list this year and I'll change the plugs again even though there's only 20,000 miles on them.

Spark plugs are normally the forgotten maintenance item. I'll bet most folks have never changed a plug in their lawn mowers! My non-Honda gasoline powered lawn equipment maintenance schedule calls for an annual replacement of the spark plug. The Honda engines call for new plugs every 2 years or 200-300 hours. I'd be hard pressed to run a lawn mower 300 hours in two years!

-- Chuck