Odd oiling question

[hardcorandy]

Normal oil pressure in my car is 10psi at 800rpm. I have no balance shafts either. Not sure if previous owner ported anything.

My car generally runs 170* in 60* weather if im out on the highway. I had just put the VRSF front mount in a few days ago. Now the temps are 195-210 as i need a radiator and new fans now. When the temp in the car hits like 205* my oil pressure goes to 20psi at 800rpm and stays doubled from the norm. No matter what my oil pressure stops at 90psi as well.

Does this have to do more with oil temp causing this? Its only done this once or twice in a year before the front mount. I would just like to understand whats going on if someone knows. Im not worried about anything. Just curious.


Thanks!

 

[ed1380]

10 psi at idle is kinda low. Either the pump or main bearings are worn. Increased temps could be causing the crank to expand and decreasing clearance would increase oil pressure

 

[hardcorandy]

The motor was rebuilt by PO. Power steering pump just fell off one day. Alternator bolt was sent through the oil pan. Everything was loose on the car, so I went over EVERY nut and bolt. I never looked to see if one of the sleeves werent put in on the BS. I wouldnt put it past the guy. Not sure what would happen if that was the case. Compression is 150 across the board. I have the standard lifter tick once in a while but the bottom end is silent. The motor has 23k on it now.

I know 10 psi is low. Especially having a BSE. Im not really worried.

 

[ed1380]

You could run some thicker oil to help with the oil pressure. What pressure do you have in the 2-3k range?
I always run 15-40 diesel, but It's also warmer here. So 10-30 in the winder. 15-40 in the summer would work for you

 

[hardcorandy]

I run 10-30. i see about 40-45psi at 3k. Ive tried thicker oil. When it thins out its fine. But when the oil is still thick i can feel the car pulling timing. My lifters hate the thicker oil and seems to drive the knock sensor nuts. I do plan on 3g lifters in the near future. Im just always looking for maintenance to be done. Had to replace everything under the front end. It never ends. But I always stay on top of everything.

 

[TSIfreek]

I would at least run 15/40 and swap out the lifters to the 3g units as this is were your getting your timing pulled from. Also porting the OFH does not change the idle oil pressure it just limits the max pressure.

 

[hardcorandy]

Lifters are in the plan. And ill try the 15-40. Im due for and oil change in 500 miles. Maybe ill order lifters friday and just get it done then. Not sure if the OFH is ported but if i take the rpms up on a pull itll fly up to 90psi and just stop like it hits a wall.

 

[ed1380]

That's the oil relief valve opening. Nothing to worry about.
4G63 Lifter removal without special tool part 1 - YouTube

 

[hardcorandy]

Seen that video before Im gonna take my cams out to do it. Ive got a little bit of oil on my front case and that sort of thing drives me nuts. So itll give me a chance to clean it up and change a gasket or 2. Thanks for the help

 

[TSIfreek]

Any were around 90 psi is were you want to be I dont like to be above that though. ED1380 is correct as that is the relief piston opening limiting the max oil pressure the engine will see. I would still like to see 20-24 psi at idle on a new motor at 900 rpm hot as this also gives me an Idea on what the bearing condition is. The 10/30 your using now will lower the idle pressure slightly so I expect the pressure at idle pressure will go up with the 15/40..

 

[ed1380]

The last motor I rebuilt hot idles at 15psi with 15-40 diesel oil, but it still has the balance shafts and the oil pump might be week. 40psi at 2k rpm.

While you're messing with the front case. Eliminate the balance shafts

 

[TSIfreek]

My comment was on an engine with no balance shafts sorry for the confusion so yes the oil pressure at idle will be higher with no balance shafts compared to an engine with.

 

[hardcorandy]

While you're messing with the front case. Eliminate the balance shafts

Balance shafts are already gone. The idle pressure thing i so weird. Had my 10 psi for a bit. Drove around for a bit, then came to a stop and noticed the 20psi again. So i decided to pull into a parking lot and just watch the gauge. as the coolant temp dropped from 205* or so to 195ish, It switched back to 10psi in the snap of a finger. So if it was a bearing expanding or contracting wouldnt it be a little slower of a process? Another thing is, when the oil is in its "high pressure mode" the needle on the gauge is really twitchy like. The slightest bit of rpm change it goes nuts. EXAMPLE> A 200rpm change is like 10psi change in oil pressure.

Upon a BLT last weekend, I noticed i can hold air for a bit but the air leaks into the oil somewhere causing me to hear bubbling. Zero play in the turbo and i do not burn oil what so ever. PCV is hooked up during the test and doesnt leak. Brand new OEM one. Its the hose to the other nipple in the valve cover that i cap. So im lost with that too. Wandering if its related somehow.