9KCanuck

One "before" image of rear of the throttle body. And then a couple from after cleaning it.

Car Analogy

Dang! That was seriously dirty. Never seen one that bad.

Looks good now though! Good job. It'll be fine. No need for further cleaning.

Think how much cleaner it is now. But I get how you want it perfect in order to sleep at night. Just don't let that desire tip into making things worse.

9KCanuck

Really? Yikes. The car has only 82k KM on it. Perhaps I'm the first to have ever cleaned it properly.

I will leave well enough alone now. Thanks for the reassuring reply.

B serious

Maybe the PO had a K&N filter or similar oiled filter?

I prefer the OEM filter unless you really think 1-2HP is worth all that junk

9KCanuck

It has an AEM cold air intake from PO. I like it, as intake sounds great... especially when VTEC kicks in

But I have wondered about the fact that it's got an oiled filter. I don't love that... but I suppose I could put any filter on the end of it.

zeroptzero

The precleaning pictures look pretty normal actually. That isn't intake dirt on there, that is just oily crankcase vapours from the exhaust gas recirc system, you get air flow from the manifold travelling back and into the rear of the throttle plate when it is closed, and the manifold is always ingesting crankcase vapours. They have that dark oily deposit look to them, similar to what you see in the ports and other manifold areas.

I didn't read the latter part of your thread in time to provide advice on cleaning. But I would have warned you against cleaning it too forcefully. Honda throttle plates are not machined to be totally tight, so they add a sealing paint/coating on the backside of the throttle plate to help it seal to the bore. You can see the painted coating on the throttle plate and it will have a corresponding layer around the bore, a greyish sealing coating which they basically put on with a paintbrush. If you scrub away the painted coating on the throttle bore your throttle body will idle higher or it will throw your idle out of adjustment as you will get more air leakage around the throttle plate. You don't see it on aftermarket throttle bodies as their plates are machined tighter, Honda throttle plates are not machined that tight so they use a sealing coating on the back side of the plate and bore when it is in the closed position.

You will see daylight around the throttle plate with the coating removed. If that happens to you after getting it cleaned up do an idle relearn procedure and see if that helps.

9KCanuck

Thanks for the info.

Yes, there is a sliver or 2 of daylight in a couple areas around the plate. Hopefully I didn't scrub any of the coating away myself when cleaning... but all I used was carb cleaner and a toothbrush + cloth.

Maybe it would have been better to leave it alone, as the gunk on there previously was probably sealing it up nicely, as someone mentioned in this thread.

zeroptzero

^ yeah it isn't the end of the world either way. While the black oil gunk looks bad it isn't intake dirt which one might think is abrasive, just oily carbon gunk. Good to clean gently. If the idle starts acting up when you get it running again you can adjust the idle stop screw a tad to get the throttle plate to close tighter, very small increments so the plate doesn't start sticking but enough to have it tight enough to regulate idle air.

noodels

9KCanuck

Good to know. I was starting to think I should look into how to reapply that painted on sealant. But it sounds like it doesn't last forever anyway and not critical.