I am currently and have been running forever it seems 10w30 amsoil dominator racing oil. Since the turbo, my temps drop to 20psi after a few wot full boost pulls and it's making me rethink if I should move up to 15w50 instead... Cold startup I am at 60psi, warm 35-40psi, and wot follows pressure fantastically. It's after a few pulls that the temps are warm and my pressure is dropping to 20psi or so.

What is everyones suggestion? I am a amsoil dealer so I'm definitely sticking with amsoil, just not sure what weight. If anyone is running 15w50, what psi are you at with turbo or supercharger setups?

 

15w-40 Rotella non-synthetic.

 

15/40 here. Turbo car as well, and my oil pressure does the exact same as you are describing. 20psi at idle is plenty safe, before I went through my motor a few months ago, at times I had even lower pressure (pinched oil pump o ring). When I pulled the motor down, the bearings showed no signs of starvation whatsoever, most even still had the coating still in place. The problems come when you start seeing a drop in pressure when accelerating.....or no rise in pressure as rpms increase. But what you are seeing is perfectly normal, and won't wreck your bottom end.

 

Oh, and my pressures are 55 cold start, 38-40 idle...with no spirited driving.....run the car hard in warm weather 22psi idle and 45 cruising....wide open 65psi. With all of this said, my bearing clearances are looser than factory and I run a high volume pump.

 

Yes basically everything you describe is exactly what is going on. You don't think I have a pinched o ring right? Or did you mean another build had the o ring? I have a ported ls6 oil pump, cold is 60-65psi, around 50psi idle with no spirited driving, after running car hard wot in warm weather, 20psi idle, 45 crusing, wide open 60-75. I have 110k miles so I am sure my tolerances are looser as well.

Would you say just leave it as is at 10w30 or switch it up to 15w50?

 

If you are still seeing 65-70 psi wide open....I doubt you have a bad o ring. And if you are seeing those pressures with 10/30 I would leave it alone. And I was talking about my motor having the pinched O-ring, which was keeping my pressure low. I pulled the motor due to glitter in the oil, which now I believe was from the turbo going bad.

 

What would be a cutoff point when I should consider switching to a thicker oil? It rarely ever has gone below 20psi after multiple wot runs hitting full boost. Also, if I idle for a bit after the wot runs, the engine will cool down and psi slowly crawls back up to 35psi-40 depending on how long I idle. Maybe 5-10 minutes. I obviously assume just because my engine bay is warmer now and the turbo is pushing warmer air into the intake that everything is heating up quicker now thus making the oil **** water.

I have a oil less turbo, but coolant is still run through it, and it's not exactly a small turbo so it does generate heat. lol

 

You could switch up now, and it wouldn't hurt anything. But i would be nervous with a 10-15 psi idle....and a weak rise with bringing the rpms up. Do you have a blanket on your turbo?

 

Yes I do. I have never had a 10-15psi idle yet and so far at least (knocks on wood) the rise in pressure vs rpms is dead on. As soon as the pedal goes to floor, the oil pressure follows.

 

Another Rotella fan here. 15/40 seems to keep everything happy, keeps pressures high (30 at idle and rises to 60+ while driving with a ported ls6 pump, even after flogging the car), and the stuff's dirt cheap.

 

And it seems to handle the added heat from the turbo rather well also.

 

Delo 15-40 is as one person said to me "Unicorn Cream" for turbo LS1's and he was right.
I've run full synthetic Amsoil 10-30 and seen significant pressure drop like your describing.
I then tried VR1 10-40 and it was marginally better but still dropping.
I switched to Delo 15-40 because it was on sale at Costco and it works the best hands down. My oil pressure is steadier and it holds up far better to repeat WOT pulls and you can't beat the price.
Don't waste your money on full synthetics, I can do two oil changes to one of a full synthetic. $.02

 

Rotella 15w 40 is what I run. Car has 40+ pressure at idle and 70+ at WOT. Never drops below 40 to 45 at idle no matter how hard I push it.

 

We're running 15-40 rotella in 169,xxx mile turbo ls1. never seen oil pressures lower than 40psi.

 

If you swap to a thicker oil it will reduce oil flow (and possibly read higher oil pressure on the gauge). I would keep using the 10-30 is the engine has an OEM tight bearing clearance, and is a daily driver (cold started frequently), and has less than 130-150k miles.



Gota watch out for this kinda post. Lots of missing info can be misleading.

1. No mention of whether this reading is taken with a mechanical or electrical gauge. I have had electric gauges read 10psi with the engine off!
2. no mention of where the oil pressure sender is installed
3. no mention of how many NON turbo miles the engine has had. Perhaps this engine went 0-> 150k with no turbo using only 10-30 and then he acquired it and decided to swap to whatever.
4. no mention of the oil pan shape or type of vehicle / driving done.
5. no mention of whether this is an OEM bearing or aftermarket bearing engine. I would assume OEM since most people don't know how to get an aftermarket bearing to last 150k+ so there it is.

And last, the only kind of oil pressure data I will trust is a mechanical gauge when at idle, OR, an actual DATA-LOG of WOT oil pressure, and ONLY given the type of engine and oil pan, and type of car/driving. (in other words, it wont matter what other people log for pressure if you don't know what kind of pan/pickup/oil related mods the engine has, and the type of launching/driving done)

Ok, and the kicker. Never seeing an oil pressure below 40psi is very worrisome! You WANT/NEED the oil pressure to drop slightly (from a COLD 40-65psi, to about 12-23psi HOT) when at hot fully warmed up idle within a reasonable rpm (800-900rpm). If the pressure never drops due to thinning oil, then the oil is NOT getting hot enough! Most engines won't have this issue so it makes me think the fellow is using a electric gauge which is wandering and perhaps cheap or not grounded properly (think of a 3 wire potentiometer, 2 prongs act as variable resistance and the third is used for a true earth so when the dial is fully turned it can send ALL current back to ground, which cheap electric gauges seem to lack).

 

^ This guy complicates almost every thread he joins.

Nobody is driving around with mounted dial indicators or multi-point mechanical gauges, or building CAD layouts of their oil pans to determine slosh and pressure increases for horizontal load, or tearing down their OEM engines to check bearing clearance just to figure out what oil to run.

Low oil pressure? Try thicker oil to see if it helps. High miles? Thicker oil for larger bearing clearances and worn oil rings. Burning oil? Try thicker oil.

Fresh shortblock? Use whats recommended for the clearance you know you have.

 

I'm in tears!! 😂😂😂😂. Funniest comment I've seen in a while.

 

Autometer mechanical gauge. The oil line to the gauge is T'ed into the oil feed to the oil feed for the turbo. Which is coming out right above the oil filter.. 16x,xxx miles. original motor never had any work internally other than an aftermarket cam was installed. never seen below 40PSI oil pressure. 15w-40 rotella. turbo has been installed for a few thousand miles. Car was being sprayed before that.

oil pan shape/type of vehicle..? i think we know what motor he is runnnin...

 

No lower than 40 psi on my new 408 and I'm using the stock mechanical gauge. It is around 60ish when cold and 45ish when hot. Runs around 70 when WOT. I was told by the shop that built the car to run Rotella 15w 40 or 20w 50 VR1 oil. This particular shop builds 8 and 9 second street cars so I'm sure they know what they are talking about.

 

Rotella 15w40 kept my bone stock ls1 w/ a T76 and 115k miles alive without issue.... and i beat the car daily in florida summer heat!