Camshaft Scraping Marks

[LANDSCRIBBLE]

So i was changing my cam cover gaskets today and i noticed on the intake camshaft these scrape marks that are on the rough part of the shaft (not the lobes)

.

What do you guys think could cause this? Is this something to worry about?

Also, i noticed on the inside/behind the throttlebody this oily black grime covering the inside of the intake manifold, wiping my finger on it, looks like i just wiped some wet black paint or something.

Any ideas/info would be appreciated, Cheers.

Edited August 20, 2011 by LANDSCRIBBLE

[Moodles2]

Don't clean that stuff off the throttlebodies, unless you want idle problems

[LANDSCRIBBLE]

Ok so that oil is meant to be in there? I wiped the black grime that was covering the outer side of the throttle body but it seemed to run normal afterwards

[mad082]

that oily black stuff inside the manifold is in fact oil. it gets there via the PCV as well as from the very small amount of oil that leaks from around the turbo seal.

as for cleaning it out, it is best done with the maifold off, but using a foaming upper engine cleaner while the manifold is still installed will take a small amount off, but expect it to foul the plugs up in the process (as it washes it down into the cylinders to be burnt up and/or pushed out the exhaust). turns the car into a bit of a smoke machine. it's somewhat amusing.

as for what moodles said about causing idle problems, if you were to then give the throttle body a good proper clean afterwards you shouldn't have any issues. you may have to initially adjust the idle though.

you don't really need to clean it out though. it doesn't have much of a negative effect unless there is copious amounts of oil there, in which case it will make the car a little bit more prone to pinging from what i understand.

[StevenCJR31]

the marks on the cam are nothing to worry bout, if you want to clean the TB then use NULON THROTTLE BODY AND CARBY cleaner, instructions are on the can, good stuff

[Moodles2]

My bad I didn't notice it was a RB25, I thought we were dealing with ITBs

[LANDSCRIBBLE]

Ok cheers for the input guys. Could i not take the manifold completely/TB off and soak the sh*t out of it? I just dont like the sound of pouring stuff into the engine that isnt petrol or air lol.

One more thing aswell! These 2 hoses marked in the pic, are they under alot of pressure? one side on each of the hoses split when i put them back on. Ive done a MacGruber and wrapped some plastic bag around it and cable tied them for the time being, was just wondering if i will arrive at the nissan dealer with oil spurting out everywhere. Thanks again.

http://www.youtube.com/watch?v=1U-0SHUD7aA

[mad082]

under no pressure at all really. they are just breather hoses. you could replace it with garden hose in the short term.

as for putting something other than fuel or air into the engine, i'm sure plenty of people initially thought the same thing about diesel, ethanol, methanol, LPG and various other things that are used as fuels and/or additives. the foaming engine cleaner is designed to be run through the engine.

but yeah, taking the manifold off and giving it a thorough clean is the best option if you want it fully cleaned. this would also allow you to use an aluminium cleaner to really get it clean.

[LANDSCRIBBLE]

Ok well theres another weekend job for me. Cheers mad082