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Discussion Starter · #1 ·
2003, 160k miles, normal maintenance, running normally. I started the valve adjustment job earlier this afternoon.

When I removed the intake manifold cover, the galleys were crusted with carbon, and oil is lightly puddled in the bottom of the manifold. Oil is clean. Pic attached is from the internet, not mine, but it's close enough. The galleys apparently work as a pressure / flow equalizer, and there's an orifice to the intake at the end of every tunnel. I'm not surprised they changed this design in subsequent years.

Cover is cleaning up fine. Based on the other thread today on oil in the manifold, I wanted to see if I should pursue further troubleshooting while I'm in here, or just hope the clogged galleys have turned my "recycler" into a condenser.

Suggestions appreciated. I'm planning to keep going on the valves and revisit this when I re-assemble.
 

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2005 Honda Pilot, 194,000 miles
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I would bet that the clogged passages are keeping the Pcv gasses from actually being recirculated back through the engine, which would lead to your oil puddles. Once you clean up the intake and the passages I think it will fix your oil puddle problems.
 

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Nobili spiritus embiggens pequeño sparus tyre.
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  • What are you using to clean those passages?
  • Are you also cleaning the EGR valve? Or replacing it?
  • Are you reusing the EGR valve gasket or getting a new one?
  • Are you replacing the PCV valve?
 

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Discussion Starter · #4 ·
  • What are you using to clean those passages?
  • Are you also cleaning the EGR valve? Or replacing it?
  • Are you reusing the EGR valve gasket or getting a new one?
  • Are you replacing the PCV valve?
  • I cleaned the cover with a screwdriver for the big stuff and a soft bristle brush, and blew it out with air. I'm not going after the varnish - just the bulk carbon. The galleys are all open, so they're easy to clean out. It's all dry, brittle carbon, no tars.
  • I haven't touched either the EGR / gasket or PCV. I can replace both easily enough if that's a no-brainer.

I hope that Depleted Islet's theory is correct - the clogs reduce flow, so temp drops, so stuff condenses. Probably back-pressures the system, too - the recycle inlet port on the manifold was really gunked up.

Unsurprisingly, everything downstream of the manifold is also carboned - riser (lightly), intakes (even less), probably intake valves, but I'm not going in that far. Plugs look fine, however - nice toasty gray-brown on the electrodes, and they're being replaced.

For those who enjoy keeping score on other's projects, front bank of valves went fine. Of the 12, maybe 6 were significantly off (exhaust too tight, intake too loose), and another 2 or 3 marginal. Valves and cams are clean - previous owner apparently changed their oil regularly.

I got tired after finishing #6, and will hit the back side tomorrow when I'm fresh.
 

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Discussion Starter · #5 ·
For posterity, and my naive faith that most people still try the "search" feature first...

- per plplplpl's suggestions, I continued upstream to both the PCV and EGR. PCV was solid with carbon, but easy to clear. I'll get a new one now that I have a vehicle again. EGR was clean. I put both back and continued.

- replaced plugs, replaced one plug tube gasket, replaced all the head cover bolt seals.

- reassembly was normal. I noted some additional carbon in the throttle body, but it started right up and ran smoothly.

- I have dabbled with the SeaFoam cult. I shot half a can into the intake after I warmed it up. It seems to run a little smoother after that, but maybe just a placebo. Either way, its definitely running smoother than it was before.

- all in all, I think it most likely that Depleted Islet's theory is correct - clearing the EGR passages lets everything breathe normally again. I'm not sure that adjusting my valves accomplished much (they were almost all close), but doing the job was worth it to mine out all that carbon. We'll see if i get ambitious enough to pull the manifold cover in a year to see how it's getting along in there.

- timing belt / serpentine belt / alternator belt are next.
 

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I’ve read a lot of pcv threads on here, figured it was a good guess! I’m glad you got it sorted out. I’ve got all my parts to do the timing belt and valve adjust here soon. Looking forward to seeing how much carbon and oil I’ve got it my plenum haha
 
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