Hi I have a 96 Maxima with 83k miles and I've replaced the valve cover gaskets and used gasket sealer where the "corners" or "valleys" are and I am still getting a leak coming down and touching the exhaust causing the engine bay to fill with smoke. I changed the oil to a higher viscosity than the previous oil (10w-30) and added Lucas stop leak which made it better but hasn't eliminated it. I feel behind the rear valve cover but don't feel any fresh oil coming down but i do feel like there may be some oil residue possibly from a leak in the previous valve cover gasket, and I know the leak is still happening somewhere and not simply burning off whatever was left on the exhaust because when the car is cold I get little oil drips on the ground before the exhaust heats up. Any idea on what components may be in that area causing this? It seems like it is coming from somewhere below the rear valve cover, on the passenger half of the engine bay. I know there is a oil pressure sensor right above the oil pan but I can see it is coming from higher up than that and it is dripping onto the axle which is above the sensor and pan.
Any ideas on where this may be coming from?!?
I will post pics once I get to my computer unless there is a way to do it from my phone...

 

Your leak is coming from the timing cover. There are two places to look for which I would start by where the covers meet by the power steering pump. There is some bends in the cover there that is a known leak spot. The other would be the rear timing cover where the power steering pump is located.

 

If you have confirmed that the valve covers are not leaking, then I would go with timing chain cover as well.

 

How difficult is this to replace? I've searched and haven't been able to find any writeups so far that make me feel comfortable doing this but if someone has the info please share!

 

Lucky for you CS_AR has been doing open heart surgery on his motor with excellent PICs;

http://forums.maxima.org/4th-generat...moval-tip.html

 

If you don't already have one, I would pick up a Mechanics Mirror like the one in the picture below and use it to look around area where you suspect the leak may be occurring.

 

Leaking exhaust valve stem seal.....

 

That would smoke from the tail pipe, not under the hood.

 

My bad I thought He sound engine oil in his exhaust.....It's a gasket leaking more like the v/c gasket...maybe when he pulled the valve cover off it spilled quite a bit of il on the exhaust manifold......Did you spray everything down withbrake cleaner once you were thru reassemblying?

 

I did clean up as much as I could but I get drips after I drive so I know it is still leaking from somewhere. I think it may be the timing cover because I see some residue coming from that area but I have to get more in depth with examining it as I just briefly looked as I was doing another repair.

 

please, i've had oil leaking onto my exhaust for years. just did a new y-pipe yesterday and i painted it with some vht header paint so hopefully it'll keep the rust away for awhile. timing cover is most likely the culprit or valve cover, could also have some power steering fluid leaking in the back mixing with it as well. i'm doing a swap this summer cause i'm sick of smelling oil leaking onto the exhaust and seeing oil under the car everywhere i park.

 

You have a 96 with 83k miles?? Thats awesome lol.

 

I was shocked as well! Pics? How's the exterior condition?

 

What above the exhaust? The valve covers!

 

Ah cmax, as stated in my first post, it is not the valve covers. Search haha...wait no need to its already in this post! Smh, the irony! Hope you have a better day And the exterior needs a paint job just due to sun damage but the body is flawless. This used to be my grandfathers car and he just drove it to church and back and to the grocery store so it didnt see many miles

 

I'm thinking the valve cover gaskets aren't sealing as good as you think. Sometimes they roll and and don't seal. Tc isn't what I would call "above" the exhaust manifold. Its to the side and probably wouldn't drip on it.

 

Well I've checked the rear of the valve cover and it is not wet so its throwing me for a loop here

 

It's gotta to be that! There's nothing else above the exhaust manifold other than the V/Covers....I think you may need to really get a good mirror and bright light, and inspect that area really well after you clean it up and run it a while you'll see it's leaking surely but slowly!

 

http://www.nicoclub.com/archives/use...-database-html
check out this link it has the full service manual for your maxima and explains in detail how to replace the timing chain cover gasket. Good luck hope this will be helpful.

 

It's also posted in the stickies, and linked in the signatures of about a dozen members here.

 

I had numerous different oil leaks over the years. The valve covers were a major pain and had to do the job a second time as I didn't do it completely right the first time.
The timing chain access plate was leaking and a fairly recent and heavy oil loss item was a leaking lower crankshaft seal even though it was done when I did the harmonic balancer pulley replacement (used a non OEM seal 'cause I was in a hurry to get it back on the road), that one leaked up front but airflow coming under the car blew it all over the exhaust and right suspension arm making it look like a valve cover style leak, screwed up my new 13" rotors as well as is got all over the pads and baked into the rotor before I found out what it was.

 

I also did this too and my oil leak is still there. I think replacing the my valve cover gasket made the leak a little bit worse because it leaks more during idle. Does having the valve covers sealed up force the oil to come out more in another area, like behind the rear TC?

I just bought the car and starting to regret it, but for some reason I also like it too.

 

DId you put RTV in the corners as instructed in the FSM? (see sig)

 

Yes I did. I actually did it a couple times because I wasn't satisfy with the first attempt. I also checked the corners and the whole circumference of the mating surface and it was good and clean.

I also crawled under the car and saw fresh oil on one of the rear exhaust manifold stud too.

It's so frustrating because I spend like 5 days tackling this job and it leaks more and now I find out that I would have to remove the UIM and Valve covers to do the TC o-ring job.

 

Probably just burning off all he old oil residue! Take it to the carwash and blast her down real good! The timing cover usually leaks down between the engine and timing cover to the oil pan... If you see no leaks then clean your exhaust manifolds off better than you did originally! Good luck! Haven't heard a peep from you so everything must be good now...

 

Torque everything to spec per the FSM? Too tight is no good.

 

As the WIZ stated over tightening can cause them to leak again by splitting the gaskets.

Another possibility is you didn't give them enough torque. Before I purchased an IN/ LB torque wrench I easily tightened them because they only require 47 to 65 IN/ LB of torque. Turns out my front valve cover started leaking near the dipstick because the bolts weren't snug. I loosened all the 10 bolts then tightened them again in sequential order using a torque wrench. That stopped the leak.

The tightening specs and RTV sealant locations are listed in the Engine Mechanical FSM.

 

Thanks for the response guys.

On the issue of the tightening the bolts, I'm pretty sure I done that correctly. I followed the sequence and the torque specs on the FSM. I did it in two stages, first stage was up to 25 in-lb and for the second stage up to 61 in-lb.

I guess the next logical thing to do is what CMAX suggest, clean all the c**p off under the car and start the easter hunt (the oil leak). I'm going to have to put this in my last to do list because right now I'm working on replacing both rack and pinion bellows, and both cv axles (boots are ripped and causing a severe vibration in the steering wheel).

 

You can't smash the gasket to that point! You'll strip the bolt hole or shear the bolt first if excessively torqued. The reason why? The valve cover bolts are shouldered bolts and bottom out on the shoulders!

 

Sorry to bring this old post back from the dead. I'm thinking about going ahead and tackling this oil leak problem during the thanksgiving holiday break and there is a chance that I might not get every thing done in time before school starts up again. I was wondering if it is a good idea to leave my engine dismantle for long periods of time like 3 weeks in the garage.

Will the parts be fine seating for this long? I'm kinda of worried that the valve cover, oil pans, and manifolds would deform a bit since it is winter here in Oregon. I assume this is not likely, but want to ask first.

So this way I can dismantle and inspect what needs to be replaced and order the parts while I'm back at school.

 

Three weeks -- no problem.. I took at least six weeks or more to go all through the 99 SE 5MT last winter/spring. No oil leaks afterward.

 

sounds like a rear valve cover gasket, if not it may be your timing chain cover

 

Use uv dye and a black light to confirm where it's coming from.

 

CS......

You do beautiful work. I see you also suffer from Perfectionism! LOL

Too bad you didn't live even closer than NJ like the old days. It would be great to have a rebuilding partner that would take the doing it right this far.

HUGE Kudos!

But when it's done and RIGHT, nothing feels better!

Keep on Rockin'.

 

I decided to google this to see what's out there now. The very first YouTube video that comes up had a very familiar engine;

http://m.youtube.com/watch?v=FgCLGXTlim0