I took the intake manifold off Saturday to install an intake manifold gasket and noticed a black liquid around the walls of the runners, mainly the 1st one, on a stock jdm R IM.

Is something wrong?

I would describe it as a black light oily fluid, and its not a lot but its definatly around the walls and looks like it went into the combustion chambers.

Should I be worried?

The engine internals is pretty much stock.

 

I believe this is just oil vapor that has condensed in there. Assuming I am correct, I think this is what an oil catch can is supposed to prevent.

Can anyone confirm this for me?

 

yeah, mine had this too, take a look at where the PCV runs into the IM, all the oil vapors and blow by gasses get routed back into the intake stream and reburned for emissions purposes.

PS...oil catch can should be installed on the PCV line between valve and IM, NOT on the line from valve cover to intake manifold, mounting it there does almost nothing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Stealth 95 GS-R &raquo;</TD></TR><TR><TD CLASS="quote">yeah, mine had this too, take a look at where the PCV runs into the IM, all the oil vapors and blow by gasses get routed back into the intake stream and reburned for emissions purposes.

PS...oil catch can should be installed on the PCV line between valve and IM, NOT on the line from valve cover to intake manifold, mounting it there does almost nothing.</TD></TR></TABLE>



On-track, I pickup close to 1 quart per half-hour in my catchcan.
Street driving picks up nothing.

 

Yup, normal. Oil vapor condensate. If you are worried about one cylinder, do a compression test. Although this is not really a good indicator of the state of the oil control rings (first to go).

Until you get to the point that you are using a couple of quarts per change like many of us, don't worry and just keep flogging it! Change your oil (and air filter!) regularly, and use good oil. You can install a catch can for the street if you really want to. Depends on your driving habits as to whether it's needed.

 

Thanks everyone. I feel better now And no, I burn little to no oil so I didn't think it was oil, I just wasn't sure what it was. Is it safe for you engine? Does it cause buildup in the ignition chamber when you burn this stuff? Just wondering if its worth it to buy a catch can or if its ok to just let the engine burn it like its supposed to.

I will be getting a compression test and dyno soon anyway, so this will let me know if anything else is wrong hopefully...

Thanks everyone again

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kay_animation &raquo;</TD></TR><TR><TD CLASS="quote">Thanks everyone. I feel better now And no, I burn little to no oil so I didn't think it was oil, I just wasn't sure what it was. Is it safe for you engine? Does it cause buildup in the ignition chamber when you burn this stuff? Just wondering if its worth it to buy a catch can or if its ok to just let the engine burn it like its supposed to.

I will be getting a compression test and dyno soon anyway, so this will let me know if anything else is wrong hopefully...

Thanks everyone again </TD></TR></TABLE>

It can just burn off, like it was designed too.

You don't even WANT to know what "real" blowby is.

Pooface: (Note, all that oil came from his PCV catchcan. I've been there too.)
https://honda-tech.com/zerothread?id=1222643

 

seafoam if your really worried about the built up oil