hi im kinda new i looked around seeing if anyone as had similar problems . i noticed my oil pressure gauge drops down after my z gets warmed up and from the passenger side head makes a tiking nosie and my 1st thoughts were that the bearings of the crank are bad cause the oil pressure drop but i took both valve covers off on each side and one cylinder head passenger side looks like its brand new with barley any oil has gotten up to it. So im thinking the oil gallery has something in it. Any advice would be great . also he motor and everything is out on a engine stand in my garage lol .

 

How low does the oil pressure drop?

 

when its cold almost to 60 on the gauge but when its warm it gos down to 15

 

using 10-40?

 

Uh, 15psi of oil pressure isn't really considered low. It's normal for oil pressure to be higher when starting the car, and drop once it's warmed up - as long as it doesn't go to 0psi, it's generally fine. And a common rule of thumb is you need ~10psi per 1000rpms... so if you're getting 15psi at idle (~800rpm), that's fine.

Post a pic of this cylinder head that you suspect wasn't receiving oil.

 

truth ^^ i had a car once that would flash the oil pressure warning light at idle and it kept running fine for a long time! i think the light came on a 10psi so i wasn't worried.

 

This is the dry side. its like its never seen oil .

 

I took the head off, an this is the block. Do you happen to know which holes are the coolant and oil gallerys, oh and which holes flow into the cylinder head and out the head

 

I'm fairly certain the narrow jets are the feed passages (visible between and above the left two cylinders and at the top right corner on your pic), and I think the large round openings (not for the head bolts obviously) are the oil returns. The odd-shaped ones should be coolant, I believe.

Was there any oil on the head bolts? The cylinder head doesn't need too much oil, as cams rotate at half the speed of the crank... your pic is inconclusive in terms of whether or not oil is getting there.

 

There was oil . I just compared both sides. One seemed alot lower on oil than the other side. The reason i took everything out was because of this dang ticking noise. fairly loud louder than the motor when it runs seemed like to was coming from the head/valvetrain. very puzzled. oh thanks for the help too

 

The ticking noise is likely air in the hydraulic lifter. Easy way to get it out is to take it on the highway at night, punch it in 4th gear and let it wind out the RPMs a bit - the increased oil pressure from the load on the engine will force the air out.

If that doesn't work, try a product called "Engine Honey."

 

now that your heads are on the bench, after they sit for a night, you can feel every lifter and see if one is soft. i successfully found my 8 bad lifters and replaced them through this method.

 

i have only drove it like once. i also bought the car like a month ago not even this is like 3rd week having it. It drove like **** above 3000 RPM , i step on it and it just didnt have punch. it felt like something as holding it back . oh i mentioned my oil gauge wrong . the gauge has markings in this order 0 then a slash then 60 then slash and then 120 . the gauge went down to pretty much 0 or like not even close to the 30 slash mark between 0 and 60 .

 

so yeah,

just cause the heads are clean doesn't mean anything other than the oil was clean. look at the cam lobes, a slight center trace wear on them, but otherwise smooth, not scored, nor showing any signs of getting head up which would happen with bare metal on metal. maybe it is time to replace the sender unit and clean the oil passages out with the old ATF trick and replace those ticking lifters. but oil flow is NOT your problem from what i have seen or heard so far. trust me. if its not running right, i'd look into a electronics problem. our brains are tricky like that, we sense a problem, and cause we notice two of the same parts that appear different we tend to believe that is the problem. but i think you are just worked up. the head looks fine and like it was in great condition, if anything, its the one that is dirty you should have been concerned about.

 

oil pressure sending units are crap on these. just replace it with an OEM and it'll last for a while. if i recall correctly i got mine at advance auto and it was less than $20. easy job.

the poor running at high revs sounds like a MAF issue. could also be a TPS issue. check these things out (there are procedures for checking them in the online FSM) and get back to us. there are many other things that bring down the power/responsiveness of the car at high mileage as well. it would run a lot better after you replaced spark plugs, fuel filter, fuel pressure regulator, fuel dampener, air filters, and pcv valves. a lot of standard maintenance parts that are often forgotten about.

 

i have a question when i removed the motor there was a single plug that wasnt pluged into anything. its the engine harness on the passenger side . it has a metal bracket with engine harness wires and it mounts to the passenger side cylinder head and for some reason who every had it before me just taped it up . in the picture im pointing to it . if i didnt take the motor out myself i prolly would never have noticed that it wasnt pluged in.

 

that might be for the EGR solenoid. is your EGR deleted?

 

its werid cause the car got 116k miles and is in amazing condition not saying they did do the maintence like this should but ya i got no problem with doing all the maintence. Ill check the online repair manual too about the maf and tps issuse u just mention . Thanks for posting and taking yr guys time

 

Im gonna take the head into my machince shop that a buddy works at tommorow and see what he has to say. i dont have the correct tools to check the lifter lash. good idea ??

 

this is the egr right ? this is on the back of the intake manifold

 

yeah that is. many people leave the valve there though to pass visual inspection after it's removed. ensure that it was hooked up properly. if it was, then that plug wasn't the EGR one.

while they're off, go ahead and get the valves ground. it'll be well worth it. or better yet, replace them. they're surprisingly cheap. i got all mine new for under $300. grand total $600 for a rebuild with new valves. i thought it was great.

 

i looked on the online repair manual. from the diagram, the plug i found that wasnt pluged can only be one of these 2 plugs circled in green. the blue circle is the location it self . the upper one is A.I.V control solenoid valve and lowwer green one is the E.G.R contorl valve. but on my car those to plugs are not where the diagram say it should be. there like right next to each other. ill prolly have to take section apart so i can connect them to there right place. that prolly why i couldnt find where the plug went cause someone rerouted the wire. Why cant people just leave the **** where its supposed to be -_-

 

i did think it looked a bit odd, but i didn't want to go throwing crazy stuff like that around! good luck figuring that out. not much but in depth investigation that can help you there. FYI, AIV is a useless system that nissan themselves admitted to not serving a function, only a failed intention. they removed it in later years. it's pretty easy to remove. the only tricky part is the plug for the cat pipe. bernie sells them, and a few other vendors sell them.

 

Those plugs are for the OEM wastegate solenoids, if memory serves. Does your car have a boost controller or Stage III ECU installed? (If it's a non-turbo, they'd just be unused connectors - I've never in my life seen a harness where every connector is used - they save money by making a harness that can be used in multiple cars.)

 

i got an N/A. if i cant find where that one gos than ill just leave it, i was just wondering if it would make a big difference.