[Vigilante375]

What is the acceptable limit for the oil PSI while at WOT for a stock car?

I'm asking this since I just noticed today that at WOT, the oil pressure would go right to 80. I've never really noticed it until today. Because I'm usually busy watching the road and glancing at the speed. I look at the other essentials afterwards.

Car is stock, around 5400 miles and oil is where it should be on the dip stick. I've watched 2 other videos on youtube showing other people going wide open on stock ZL1s and both have gone up to the next tick mark on the oil PSI and no further.

I haven't really found anything on here bur am still searching the web at the moment.

[Gunkk]

45?

[Deakins]

Sounds like for some reason your oil control solenoid is opening up a lot when it should be opening a little. I've searched the FSM and have found literature on low oil pressure but have not found anything on what to do when it's too high. I'll look more when I have time but hopefully someone else can chime in on this one.

[collinms]

Originally Posted by Vigilante375

What is the acceptable limit for the oil PSI while at WOT for a stock car?

I'm asking this since I just noticed today that at WOT, the oil pressure would go right to 80. I've never really noticed it until today. Because I'm usually busy watching the road and glancing at the speed. I look at the other essentials afterwards.

Car is stock, around 5400 miles and oil is where it should be on the dip stick. I've watched 2 other videos on youtube showing other people going wide open on stock ZL1s and both have gone up to the next tick mark on the oil PSI and no further.

I haven't really found anything on here bur am still searching the web at the moment.

Was it fully warmed up? It's cold in Georgia.

[Vigilante375]

Originally Posted by Deakins

Sounds like for some reason your oil control solenoid is opening up a lot when it should be opening a little. I've searched the FSM and have found literature on low oil pressure but have not found anything on what to do when it's too high. I'll look more when I have time but hopefully someone else can chime in on this one.

I found something thread's on the vette forum and someone stated something about how the variable displacement oil pump and how it works.

BUT, what he mentioned makes it seem like if it goes above 72 PSI..... it's doing so because of a "spring" failure....

Per the thread I found on the Z06 subsection;

LUBRICATION

Calibrated with a spring that determines the pressure curve, an active displacement oil pump unique to the LT4 helps increase efficiency. For normal operation, the pump provides 44–58 psi of oil pressure. As engine speed goes up, bearings require more oil, so pressure increases to the 65–72-psi range. In case of spring failure, the pump defaults to the higher pressure.

Guess it's a good thing I'm going to the dealer tomorrow for the front end links TSB.

[Vigilante375]

Originally Posted by collinms

Was it fully warmed up? It's cold in Georgia.

Yes. I had been driving for about 30 minutes. They were all at or under 200, except the transmission was a bit lower as usual. Oil PSI was just under 40 during the entire drive.

[collinms]

Originally Posted by Vigilante375

Yes. I had been driving for about 30 minutes. They were all at or under 200, except the transmission was a bit lower as usual. Oil PSI was just under 40 during the entire drive.

That sucks man, good luck.

[Deakins]

So, from my understanding of the system the spring is there to ensure that in the event of a solenoid failure the pump will default to the high flow setting, and thus not allow the engine to expire due to lack of oil pressure. For what it's worth, most will never see all that much over 50 lbs of pressure even on the racetrack. However, I do not know whether the solenoid has to have a fully functioning spring to properly meter flow and what affects a bad spring may have on pressure.

I have been researching this a bit to understand the piston oiling feature of the system and that has led me into how the oil pressure is metered. As I stated before, the FSM section governing oil pressure only talks about if it's too low and is mum on a situation like yours (at least as far as I've found). I would like to know what parameters the EMC is using to determine the oil flow setting. Let us know what the dealer says, Alldata should have a troubleshooting tree for this problem and I'd love to have it lol. Hope this helps.

[Vigilante375]

Originally Posted by Deakins

So, from my understanding of the system the spring is there to ensure that in the event of a solenoid failure the pump will default to the high flow setting, and thus not allow the engine to expire due to lack of oil pressure. For what it's worth, most will never see all that much over 50 lbs of pressure even on the racetrack. However, I do not know whether the solenoid has to have a fully functioning spring to properly meter flow and what affects a bad spring may have on pressure.

I have been researching this a bit to understand the piston oiling feature of the system and that has led me into how the oil pressure is metered. As I stated before, the FSM section governing oil pressure only talks about if it's too low and is mum on a situation like yours (at least as far as I've found). I would like to know what parameters the EMC is using to determine the oil flow setting. Let us know what the dealer says, Alldata should have a troubleshooting tree for this problem and I'd love to have it lol. Hope this helps.

All that I can find doesn't say anything much about high oil pressure except for what you mentioned. I will see what the dealer says and hopefully has someone trained on this engine.

I did another pull this morning, twice, after driving for 30 minutes again and it still goes up to 80 PSI.

Now here is another question for someone. I had my oil changed at the dealer last week. If there were to overfill the oil, would it cause this? The dip stick just seems to hard to gauge but the oil does go onto the coiled part of the dip stick by a good bit, maybe 6 inches. But I've always contributed it to the residual oil that is in the tube, like all my other vehicles.

[SFV1LE]

Originally Posted by Vigilante375

All that I can find doesn't say anything much about high oil pressure except for what you mentioned. I will see what the dealer says and hopefully has someone trained on this engine.

I did another pull this morning, twice, after driving for 30 minutes again and it still goes up to 80 PSI.

Now here is another question for someone. I had my oil changed at the dealer last week. If there were to overfill the oil, would it cause this? The dip stick just seems to hard to gauge but the oil does go onto the coiled part of the dip stick by a good bit, maybe 6 inches. But I've always contributed it to the residual oil that is in the tube, like all my other vehicles.

If your oil is 6 inches over the cross hatched piece at the end of the dipstick after removing, wiping and reinserting, if it its actually covered in a coat of oil for 6 inches along the wire cable arm, you have a MAJOR overfill.

If it's that far up is sounds like you have an extra 1-2 quarts in there. That would explain high pressure. I would drive it slowly, partial throttle under 3000 rpm only with no boost, to the dealer or shop for a drain and refill. Have them drain into an empty large container so they can measure what comes out and verify the level you had in there in case you have damage caused by the dealer that did this. Take photos of everything.

[Alain]

6 inches over the full line ?! That’s a problem dude.

1- are you checking the oil while the engine is running?
2- are you getting excessive white smoke from the exhaust?

Take it back to the dealership that changed the oil and have them drain and check the amount they put in there originally. Make sure you’re in the shop with them while they are draining the oil so they don’t try to pull a fast one.

Good luck

[Vigilante375]

Originally Posted by SFV1LE

If your oil is 6 inches over the cross hatched piece at the end of the dipstick after removing, wiping and reinserting, if it its actually covered in a coat of oil for 6 inches along the wire cable arm, you have a MAJOR overfill.

If it's that far up is sounds like you have an extra 1-2 quarts in there. That would explain high pressure. I would drive it slowly, partial throttle under 3000 rpm only with no boost, to the dealer or shop for a drain and refill. Have them drain into an empty large container so they can measure what comes out and verify the level you had in there in case you have damage caused by the dealer that did this. Take photos of everything.

Originally Posted by Alain

6 inches over the full line ?! That’s a problem dude.

1- are you checking the oil while the engine is running?
2- are you getting excessive white smoke from the exhaust?

Take it back to the dealership that changed the oil and have them drain and check the amount they put in there originally. Make sure you’re in the shop with them while they are draining the oil so they don’t try to pull a fast one.

Good luck

Like I mentioned. I do not know if it's the residual pull that is in the tube. Seeing as all other dip sticks have always been flat. And no, I'm not checking it while it's running. It's always after the car has set for at least 30 minutes.

I know too much oil isn't a good thing and no, there is no white smoke coming from the exhaust or anywhere else on the car.

I'm sitting at the dealer now, waiting for the tech that knows about these engines. I will also get them to double check the oil level. I highly doubt they'll change the oil "just because".

Like I said oil pressure is fine at idle and cruising down the road. I can only wonder if the dealer didn't let all the oil drain when they changed it or actually put in too much oil.

[Alain]

My dipstick (and everyone else’s) reads fine after the car as been sitting for 30 minutes. Has nothing to do with the dipstick being flat or not.

If you have that much oil in the dipstick tube then that tells the story. Good luck man. I would watch the technician like a hawk while they inspect your car

[Vigilante375]

Talked with the tech and he rode with me doing a WOT run. He knew my concern and had some knowledge. Though he and the service manager may have blown some smoke in my direction on 1 thing but technically makes sense.

But, he watched the gauge and said it was at the limits of what is specific to the ZL1. 55-75 psi are the limits, set by GM (SI DOC 3995923), measured at the oil pressure sensor (active fuel management relief valve oil pressure). And he said with the gauge being digital, it doesn't "catch up" to the true reading. Which I can understand but whatever. Data logs will show the true readings. I really do wish these gauges could be displayed as a number, that would be a bit more helpful.

They ran a diag and everything came back ok but that doesn't mean something physically could be wrong. It's documented and I'm not planning on modding the car so it'll all be covered under warranty for a while.

He said the oil level was ok. But the dip stick does make a difference on how it can read. Go to a 92 Camaro, pull out the dip stick and see what I'm referring to. You can make that dip stick not grab the residual fluid on the side. Where as this wire dip stick will always touch the side, causing the oil to cover it. It's not a stiff piece of wire, it will bend.

I guess I'll keep an eye on this and see how things go down the road...thanks for the help and I'll bring up anything that happens down the road.