Look here:

http://s87266458.onlinehome.us/album...0073.sized.jpg

My mechanic said this:

"Valve cover gaskets are leaking, the oil is wicking up the intake plenum risers, replace the valve cover gaskets, remember not to over tighten the valve cover bolts. The oil is coming from the valve cover, that is what is leaking, not the plenum."

Sooo, is this true? And how many gaskets do I need to buy to fix this? And, is it a DIY?

 

theres only one long rubber gasket under the intake manifold. if thats all thats leaking, then its not too difficult to do it yourself, though i wouldnt think that would cause the leak....you could always take it off and inspect it, just takes maybe an hour or two. tough to say without looking at the car....hope that helps.

 

i'm curious too, my engine looks the same as that

 

actually, though, it looks like it is leaking in front of the valve cover too. is yours?

 

If the intake plennum gasket was leaking you would have idle problems caused by air being pulled in, not oil being expelled. There are no oil passages around the intake and it's usually under a vacuum, not under pressure.

I would use some engine cleaner and clean up the top of your motor really good. Then watch closely to see where the oil is coming from. My vote goes to one of your valve cover gaskets.

 

hey that sort of relates to another problem i have, which is a lean condition. do you think it could be related?

 

Man, and I thought my plenum looked bad J/K . I've been having that issue with my car for a while now. My plenum only has a little bit on it though, just toward the drivers side of it. I just wipe it off when I change my oil or something. I went to my local Nissan dealer to ask them about it (maybe a couple of years ago), and the mechanic told me not to worry about it. He mentioned exactly what njmaxseltd said, and that I would definately know if my plenum was leaking. So in a couple of years it has not gotten worse, so I will just keep wiping it every oil change or whenever I check under the hood.

 

yeah but in the mean time, you are losing oil

 

So, I might have missed it in other posts, but how many valve cover gaskets are there, and is this a DIY job?

My mechanical scope: I am able to do brakes, suspension, belts, oil changes, etc, on the car, but I've never done any gaskets.

 

I think that would answer your question.

 

Yeah, something like a couple of drops in between oil changes.

Actually, I have not noiticed a drop in oil volume, at leat not enough to be able to be meausured witht the dipstick. Just before I change the oil, I check the dipstick and the oil level is ok.

 

I looked in my chilton's and found some answers I'm looking for:

There are two valve cover gaskets... a front bank and rear bank.

To remove the front bank valve cover gasket:

1. Disconnect negative battery term
2. Remove the decorative facia on the valve cover (Nissan 3000 blah blah)
3. Disconnect the electrical plugs on the ign. coils
4. Remove the ignition coils
5. If necessary, disconnect the electrical connectors from the camshaftsensor and the power transistor
6. Remove the valve cover head nuts and take off the valve cover! Throw away the gasket! Cake!

To install new front valve cover gasket:

7. Thoroughly clean the gasket mounting surfaces.
8. Using liquid gasket sealant, apply a continuous bead to the cylinder head and the valve cover.
9. Using a new gasket, install it onto the cylinder head. Put the valve cover back on and torque the nuts in the following order:

a. Torque all the nuts, 1-10, in sequence, to 9-36 in.lbs (1-3Nm)
b. Torque all the nuts again, 1-10, in sequence, to 47.7 - 65.1 in.lbs (5.4 - 7.4 Nm)

10. Reconnect and install everything just like you took them off.
11. Start engine and check for oil leaks.

.....

Rear bank valve cover (little harder) I'll post the exact stuff later, but this one is the same procedure basically (you take everything off the rear valve cover, including the hoses, accelerator cable on throttle body, intake manifold collector, ignition coils, and then finally the valve cover + gasket)

 

Mine looks worse than that,and my mechanic shrugged it off. I too thought it was the plenum, but what njmaxseltd said makes a whole lot of sense. Maybe in spring I'll take off the valve cover and replace the gasket.

 

why is it that every single person to post is talking about his friggin intake gasket when he clearly said VALVE COVER GASKET!! c'mon people, you look like morons when you dont even read this crap. no oil goes through the intake?? NO CRAP, he said its the valve cover. good job finding the info colossus, sorry i didnt see this earlier.

 

you should go live in the hills and not bother anybody

 

ive wanted to do that since i was very young actually. people do bother me, but it really isnt hard to see where he discussed the whole problem, so i just didnt understand why everyone was talking about intake gaskets. honestly, i dont wanna make anyone mad at me, just got a little overzealous i suppose. anyhow, sorry if anyone was truly offended, but i just like to see people get good quality help here.

 

he asked a question

 

I never mentioned "intalke gasket", please don't generalize

 

ur mechanic could be right if in fact it is leaking from the valve cover... take a better pic...if in fact it is splashing from the valve cover(i dunno cuz i cant really see in that pic) then just replace it its easy... if its leaking from the collector... (Akumachan... oil splashes all the way up to the the inside of the collector...) its a 6.35$ part from the DEALER!!!!! i just replaced it this week..it took about an hour and a half...

 

i didnt mean to say that the valve cover is all that could be wrong, all i was saying is that all anyone was saying is that it couldnt be intake gasket, but he already knew that, but thanks for your input f550.

 

The valve cover gaskets are easy to do. Just takes some time. It was the first DIY fix I did on my car. Might as well replace the Plenum Gasket while you are there. It only like 15 bux from the stealership. And definately dont over tighten the valve cover bolts. If you do, you WILL break on off. Trust me. I broke on off on the rear cover and had to put everything back together and drive to a place to have my mechanic remove it, but I didnt want to pay for the labor so I removed all the crap again and let him drill it out and I put it all back together again. I can do a valve cover gasket job in about 45 minutes now.

Dub

 

It is indeed possible for the leak to be from the gasket between the upper and lower intake manifolds.

1. Oil vapor exists in the intake manifold because of the PCV valve.
2. Although there is vacuum in the intake at idle and during cruising, the vacuum goes to zero at WOT. At that time there are positive pressure fluctuations in the runners because of the inertia of the air flow acting against the intake valves when they close. The positive pressure will push the oil vapor out at the gasket.

The rubber gasket is cheap and is the easiest to replace. Do that first. This is probably the cause of guttermouf's lean condition, too.