whats up y'all... i have a 08 hr 5at.. its got about 6400 miles on it and the things that bugs me is my oil pressure gauge reads 120 psi but it goes away after driving about 10-15 miles... i understand that it is possible to reach that high pressure only when im gunning it.. but it happens even when im just starting to drive off.. i use tiptronic pretty much everytime and i never noticed it being that high before. even when im only going 20 mph@ 1500-2500 rpms..

i took it back to nissan and the tech said that it was completely normal.. what they did was a tech test drove it and said that it was completely fine.. he said that the pressure would reach that high when im at 4k rpms... but when i drive it, it peaks out at low rpms.. is it the way i drive.. never changed how i drove it and never had that problem with anyof my cars or when i first got my z... i dont even think the checked how much pressure the engine was pushing..

the other weird thing is that i asked them what the difference was between an HR and a DE and they didnt know there was another engine type...

hope i explained this enough and clear.. ive seen one thread that had the same issue but i didnt seem to get a clear answer. pls help me.. i just want the best for my car.. just making sure that everything is good before doing mods... N/A all the way... thanks for all or any inputs y'all can put in

 

when the engines cold, it's normal for the oil press. to be a little high.

 

well i understand that but dont u think 120 psi driving @ 35-40 mph too high

 

it just feels like i dont have same power i had before...

 

Not really. My Z does the same thing, and once the engine warms up, the pressure goes down to normal levels. My Z only has 7400 miles.

 

This is completely normal. Engine oil is thicker when cold, so as the pump tries to move the oil even at lower flow levels, the pressure reaches a bit higher. Nothing to worry about unless you see too low an oil pressure. When hot I think I always maintain above 20 psi (idle no load), and it only gets that low when its REALLY hot.

As for the power, its summer, its like 95 out right now, the engine doesn't make the same power in 95 degree air as it does in say 70 degree air. I noticed a 4 mph variance in trap speeds at the drag strip, which is, huge to say the least, with a 20 degree temp change (72-92).

I'd bet thats all it is.

 

do u have a 5at also? im just very cautious.. i dont know.. but thank you for ur input.. everyone else seems to be telling me that it is way too high.. have u dont anything to ur ride?

 

i appreciate all the inputs.. this will help me calm my nerves... i knew i shouldve bought a manual tranny...

 

off the topic.. u guys know any good shops in jacksonville, fl?

 

+1... I think its just cause you just started your car up. Every Z does it. You really are making a bunch of fuss over nothing. If you think we are lying then go take it to the dealership if it is still under warranty.

 

Try this, let the car sit and idle for a couple minutes before driving, let the engine temp come up to almost half on the gauge. See if it happens then. If not, it's normal.

 

that is completely normal. oil takes quite a bit to warm up and reach its nominal viscosity. even if you've let it sit for a bit, and your water temp guage is halfway up, you may still see oil pressure up a bit high for a bit.

nothing to worry about.

 

I have posted diagrams and comments about the oil pressure sensor unit several times. Don't mean to put you off but search.

 

I don't have anything that would effect my oiling system done to the car, and manual/auto shouldn't matter for this, in fact, auto might load the engine more at low RPM's because the torque converter could be unlocked (could....being the key here).

It is completely normal for these engines, they have VERY high oil pressure, it freaked me out at first, I was used to 15 idle hot, 55-60 redline, hot, 75 redline cold, and 20 idle cold. My car now has 35-50 idle cold (depending on weather and weight), and 20-30 idle warm, with 120 at redline...huge difference, but completely typical.

For what its worth I've watched my oil temps, and it took nearly 30 minutes for them to reach "standard" temp range where my idle pressure was between 20-25 psi.

 

What about the little dinky oil filter.. Is the high pressure at the filter? I know of no filter that has a blow off valve that can handle that much pressure. Does it just bypass?? That is a hell of a lot of pressure. Mine has the same pressures as noted... But somehow I keep thinking that little lawn tractor filter is not up to par!!

 

I have no idea, other than that maybe its a draw through filter.

 

Yea I would really like to know what the deal is.. I have a 550 porsche replica with a super built type one and we have to run a special filter on it to handle the pressures.. And its only 80psi.. Obviously it is just fine as I am sure that out friends in Nissan japan design know what they are doing.. But would like to know how the system works...

 

Hope this helps. I'm about to crash on ambien, but I think more or less, the answer is that there is a relief valve in the filter, a very high pressure relief valve if I had to guess.

 

Sorry about the Ambien.. I work for Sanofi-aventis and we make Ambien.. So your diagram answers my questions and if correct that high pressure would bypass the relief valve on the filter.. I need to get this figured out. Will see my master mechanic at my dealer to see what he knows.. Thanks for the great diagram!!

 

No problem just print screened the OEM service manual, and the ambien is helping.

I had some leftover my my ex gf's prescription after she tried to kill herself on it.

I've been having trouble focussing at work, and sleeping at night. An ambien and 10 hours sleep at least keeps me from dozing off at work. As long as I don't try to kill myself (posting a little out of it now, not suicidal) I think I'll be good LOL.

Edit, and to answer, I think its basically a valve that snaps open should the oil filter get clogged. It might open at 140 psi (and just get stuck open) so that you get slightly dirty oil in the engine, instead of no oil at all.

I've got an oil filter sitting in my garage (used) and I'll cut it open in the name of science/distruction.