Low Oil Pressure 2013 ZL1

[evonschu]

Hey all. I have a 2013 ZL1 that is pretty heavily modded (See signature and attachments for details). I've noticed the oil pressure at warm idle seems low (12-15 PSI - see photo). When I rev it/drive around it does go up as the revs increase. About 30PSI at steady 2K RPM and 35-45+ PSI if I get on it more. Cold Idle its about 35-37 PSI. Estimating all this from gauge cluster readout. I saw one post about 10PSI per 1K RPM is acceptable, but don't know the validity of that...

I emailed Jordan at JDP who did most of the upgrades to it years ago and he said "It could be from bearing wear or the check valve in the pump could be sticking/failing. It could also be the o-ring from the oil pick up into the pump." ...which all doesn't sound good. I have a Melling High Pressure Oil Pump (MEL-10295) as part of the supporting upgrades they put in with cam, meth, etc.

The car is driving fine with no CELs and all other readings look normal from the gauges and my dual scan gauges. I checked the dip stick and oil level is fine. Oil was last changed within the last 500 miles or so and when I check it shows full on dipstick. I did have the dealer I got it from change the oil last time I did it with the last of a free punch card I had from them when I bought it. It possible they put in the wrong weight oil? I can't remember when this started or if it was like that before that was done. Never tracked it and is not a daily driver. Usually just take it out on cruises and such.

I did have to get a replacement cam and upgraded to Johnson lifters years back after one of the stock lifters failed and scored the cam.

Just curious what everyone's thoughts on this are and if there are any easy things I can check or replace before getting into potential oil pump related repairs, which I'm sure will be costly. Thanks.

[0stones0]

The gauge reading is a “guesstimate” but, that seems a little lower than what I’m used to seeing which at hot idle is around 16-18 psi. And that is with the oil at full temp (around 225 or so). You don’t appear to be at temp yet, with it being that low.

[bsn]

Take a reading with a mechanical gauge to verify its not a faulty sensor. Next thing to try would be an oil change.

[Risingson05]

Pressure relief valve could be sticking but I doubt it .


Might be too late but would have been a good ideas to have your filter cutt open to inspect if there’s and bearing material in the filter media .

Sorry to bearer of bad news but the 10295 is actually a downgrade for the zl1
The stock equivalent oil pump is the 10355 but you won’t see past 52 psi unless you change springs .

Upgrade for the oil pump is the 10355HV
We have oil squirters that require additional psi .
My hot idle oil pressure is 33 psi at idle and 75-80 psi at wot .

It’s possible running that pump for the years that you’ve been driving could have made your main bearing or cam bearing wear out and cause more space between them .


It also could be a lazy oil pressure sensor aswell . getting a mechanical gauge on it to check it is a good idea in helping you to figure this out .

[evonschu]

Originally Posted by Risingson05

Pressure relief valve could be sticking but I doubt it .


Might be too late but would have been a good ideas to have your filter cutt open to inspect if there’s and bearing material in the filter media .

Sorry to bearer of bad news but the 10295 is actually a downgrade for the zl1
The stock equivalent oil pump is the 10355 but you won’t see past 52 psi unless you change springs .

Upgrade for the oil pump is the 10355HV
We have oil squirters that require additional psi .
My hot idle oil pressure is 33 psi at idle and 75-80 psi at wot .

It’s possible running that pump for the years that you’ve been driving could have made your main bearing or cam bearing wear out and cause more space between them .


It also could be a lazy oil pressure sensor aswell . getting a mechanical gauge on it to check it is a good idea in helping you to figure this out .

That's odd. I had JDP put that in about 10 years ago. Maybe at that time it was the only one available? I know they mentioned they were doing that because the stock ones were prone to problems.

Wouldn't those cam bearings had to have been replaced when I had the cam replaced from that lifter damage a few years ago? I've probably only driven about 5K miles since then sadly.

With this issue, barring that it's not just a faulty sensor, is the car safe to drive until I can get this looked at further? I also have upgraded valve springs already.

[evonschu]

Originally Posted by 0stones0

The gauge reading is a “guesstimate” but, that seems a little lower than what I’m used to seeing which at hot idle is around 16-18 psi. And that is with the oil at full temp (around 225 or so). You don’t appear to be at temp yet, with it being that low.

That picture was taken after driving around for 20 mins and is usually what the oil temp sits at when fully warmed up. Granted I'm in the Pacific NW which is generally cooler outside and I hadn't done any hard pulls or anything before I shot that, if that makes any difference.

[evonschu]

Originally Posted by bsn

Take a reading with a mechanical gauge to verify its not a faulty sensor. Next thing to try would be an oil change.

If they did put in the wrong weight for some dumb reason, would that cause this kind of behavior? I'm guessing from too thin of a weight.

[Risingson05]

Originally Posted by evonschu

That's odd. I had JDP put that in about 10 years ago. Maybe at that time it was the only one available? I know they mentioned they were doing that because the stock ones were prone to problems.

Wouldn't those cam bearings had to have been replaced when I had the cam replaced from that lifter damage a few years ago? I've probably only driven about 5K miles since then sadly.

With this issue, barring that it's not just a faulty sensor, is the car safe to drive until I can get this looked at further? I also have upgraded valve springs already.

I had my motor out and when looking at the cam bearing I didn’t liked what I saw , so decided to replace them .

Most don’t replace cam bearings when doing a cam . Although, I’m sure it’s possible to change cam bearings while motor is in the car ,more easier to take the motor out as you have to replace them with a cam bearing tool/hammer

If it were me , I probably wouldn’t drive it especially if the valve train is making noise . If it’s truly low oil pressure than you can risk even more damage .

[evonschu]

Originally Posted by Risingson05

I had my motor out and when looking at the cam bearing I didn’t liked what I saw , so decided to replace them .

Most don’t replace cam bearings when doing a cam . Although, I’m sure it’s possible to change cam bearings while motor is in the car ,more easier to take the motor out as you have to replace them with a cam bearing tool/hammer

If it were me , I probably wouldn’t drive it especially if the valve train is making noise . If it’s truly low oil pressure than you can risk even more damage .

I don't hear any unusual noise from valve train. Thanks for the input though. Will keep it garaged until I can get some funds to have this looked at then. I have 2 other vehicles I can drive so not the end of the world.

[FasNuf]

Ask JDP if they removed the AFM/DOD pressure relief valve in your oil pan. It's another potential problem and our engines doesn't need it.

[evonschu]

Originally Posted by FasNuf

Ask JDP if they removed the AFM/DOD pressure relief valve in your oil pan. It's another potential problem and our engines doesn't need it.

Even if they did the dealer had to replace the oil pan years back (2nd to last punch oil change) because someone at one of the many shops I've had this at stripped the threads so bad they put a heloc in there and that was messed up. Was a fun story at the dealer as they had get the oil plug in to get it off the lift as it'd be a few days to get the new pan in. Where they parked it in the showroom the threads were so stripped it was enough to slowly leak the oil out overnight and made a massive puddle of oil in there.

Would that be a part that comes with the oil pan that the dealer would have put in that shouldn't be there and causing this issue?

[0stones0]

Originally Posted by evonschu

That picture was taken after driving around for 20 mins and is usually what the oil temp sits at when fully warmed up. Granted I'm in the Pacific NW which is generally cooler outside and I hadn't done any hard pulls or anything before I shot that, if that makes any difference.

Noticed your gauge shows 210 where mine shows 200. Didn’t see that 1st off. My mistake, you were obviously at temp.

[FasNuf]

Originally Posted by evonschu

Would that be a part that comes with the oil pan that the dealer would have put in that shouldn't be there and causing this issue?

Not sure if new pans come with the PRV,, but any PRV can stick open/closed and cause issues. Just something to check when you drop the pan since it's not needed for the LSA.

[Batmanntexas]

Just my $.02 here, but I don't believe your issue is from the relief valve in pump, as those fail in a 'Zero pressure' state. I also don't think the O-ring is a culprit, as that issue would have presented itself after re-assembly, not years later. If the oil pan has the relief valve, then I'd be willing to bet that it is not causing you issues either, as it is normally closed and only opens when pressure exceeds the spring pressure keeping it closed (50-ish psi).

If I read your initial post correctly, the low oil pressure issue started fairly recently, correct? If so, then I don't believe the issue would be that the pump is not supplying the enough volume/pressure, as you would have had the low pressure issue from the beginning (after the modifications).

Wrong oil viscosity would definitely exhibit this type of behaviour, but again, you would have noticed this directly after the oil change.

A faulty sensor might be the cause, but this can only be diagnosed either by swapping sensors, or utilising a mechanical pressure gauge to verify pressure.

Worn bearings (most likely cam) are probably the culprit here, unfortunately.

Good luck with it, and please let us know what the issue was.

-Scott