3.5l oil pressure issue poll. How did you fix it

[Junkyard_Mad-Scientist]

So since my issue is covered a lot of different ways but none exactly I thought I could do my very first post as a poll.

I have a 13 SHO with a low oil light at idle, it's sporadic but seems to be getting more frequent quickly. I have had the car less than a week and it was serviced at ford less than a month ago for the water pump where they also did the chain and tensioner. That's where it gets interesting, fresh repairs and now an intermittent oil light.

I'm starting with the sensor but I'm curious as to how many have fixed the issue with a sensor vs how many have had to dig in to the engine, or how many had a catastrophic failure. My goal is to see the odds for not only my own situation but so there's a visible trend for others to see.

 

[SHOdded]

did this happen right after an oil change? that is typical of a sensor issue. as it is now leaking enough to not be able to do its job. any codes or other issues?

 

[Junkyard_Mad-Scientist]

did this happen right after an oil change? that is typical of a sensor issue. as it is now leaking enough to not be able to do its job. any codes or other issues?

I'd say within 500 miles of a fresh oil change before it started happening. Only codes it threw was o2 sensors bank 1 bank 2 after a few hard traffic hops the day I bought it. I cleared them and it's been quiet since. No noise from the engine bay, pulled the oil cap while running and at temp and it's like a hurricane of oil in the valve cover.

 

[J persons]

Make sure you are using a quality synthetic 5w30 oil. If it's still has the low oil light, replace the oil pressure sensor, they are cheap and failure prone on almost all cars.

 

[Junkyard_Mad-Scientist]

Make sure you are using a quality synthetic 5w30 oil. If it's still has the low oil light, replace the oil pressure sensor, they are cheap and failure prone on almost all cars.

I've seen a lot of favor towards the synthetic blend and to stay away from full synthetic for these cars. I have run Mobil 1 in everything I own until recently I switched to Valvoline Advanced so I'm all for full synthetic. From what I've read the MC blend is what makes the car happy and what's currently in it. Are you running full synthetic and if so what kind?

The switch is coming today or tomorrow and I'm replacing it tomorrow, if that doesn't work I planned on doing an oil change just to ensure the correct oil is in the car to rule that out. if it persists I've already priced out a Melling pump and pick up.

 

[J persons]

I've seen a lot of favor towards the synthetic blend and to stay away from full synthetic for these cars. I have run Mobil 1 in everything I own until recently I switched to Valvoline Advanced so I'm all for full synthetic. From what I've read the MC blend is what makes the car happy and what's currently in it. Are you running full synthetic and if so what kind?

The switch is coming today or tomorrow and I'm replacing it tomorrow, if that doesn't work I planned on doing an oil change just to ensure the correct oil is in the car to rule that out. if it persists I've already priced out a Melling pump and pick up.

The problem I have with the synthetic blend is that it can be blended as little as 30% synthetic and still be called "synthetic". I've had my '14 SHO since it was new and originally used the Motorcraft synthetic blend every 3K miles. Then I learned about the minimal 30% standard and felt that I was being cheated a little. To me, a blend of two types of oil would be a 50-50 blend, but it's not. I now use Castrol Edge. It's 100% synthetic and usually cheaper than the MC synth blend. So far, I haven't seen any difference in the performance of the oil. What I have seen when using a full synth lubricant is using Redline lightweight Shockproof lub e in the PTU and rear diff. The car immedietly ran smoother and quieter than with the original lubes.

 

[ShoDoGo]

I've never trusted 'idiot' lights. Some of them stay lit with as little as 5 psig. That's well into the engine self-destruct zone. If I was in your situation I would temporarily plumb in an oil pressure gauge to determine if there is an actual oil pressure issue.

 

[Junkyard_Mad-Scientist]

The problem I have with the synthetic blend is that it can be blended as little as 30% synthetic and still be called "synthetic". I've had my '14 SHO since it was new and originally used the Motorcraft synthetic blend every 3K miles. Then I learned about the minimal 30% standard and felt that I was being cheated a little. To me, a blend of two types of oil would be a 50-50 blend, but it's not. I now use Castrol Edge. It's 100% synthetic and usually cheaper than the MC synth blend. So far, I haven't seen any difference in the performance of the oil. What I have seen when using a full synth lubricant is using Redline lightweight Shockproof lub e in the PTU and rear diff. The car immedietly ran smoother and quieter than with the original lubes.

I'll definitely keep that in the arsenal for diff time, ford just did the diffs before I bought it so I can focus on the problem at hand. As for the engine oil, no other way to put it, I'm scared. And when I get scared I rely on the manufacturer recommendation. I'd be open to trying synthetic for the health of the motor if I can get this stupid light to go away. I may even try it in an attempt to get rid of the light. Anything to avoid a 20 hour oil pump job.

 

[Junkyard_Mad-Scientist]

Little update on my own situation. A seemingly easy to obtain sensor is becoming difficult to hunt down. People keep saying they have it only to say nevermind have to order it, even the people I ordered it online from (Amazon seller) said they have to order it so it went from next day to next week, beyond my lift window. So now I'm calling dealers in the morning but when I crossed the part number I had 2 come back, what part number to I need? I had ordered Motorcraft SW 8368 but ford's website shows that one plus one other one, one labeled switch and one labeled sender. They look identical and both say "also called switch" or "also called sender". Gonna pick the ford guys brain bit does any one know?

 

[Texas Marauder]

SW8368 is the correct sender. It is used on many vehicles for many years. Should not be hard to find. Standard Motor Products PS427 will also work.

Buy directly from Amazon.

 

[Junkyard_Mad-Scientist]

Update: got a really helpful parts guy at ford and between our two heads we figured out that this switch has had 2 revisions. SW8368 comes back as the most recent and correct one for the car. And for anyone that knows ford part numbers the ford part number ends in B signifying a ford revision to the part. Unfortunately there were no notes as to why it was revised specifically or when the revision happened. Amazon wants $21 ford wants $66 but I can have it today. I'll update again after it's replaced

 

[J persons]

Rock auto has the oil pressure switch, Motorcraft SW8368 for $17.48

 

[Junkyard_Mad-Scientist]

Rock auto has the oil pressure switch, Motorcraft SW8368 for $17.48

I have a buddy letting me use his lift this weekend so I was trying to get it for today, I'm 2 weeks out of abdominal surgery so bending and crawling are kind of out of the question, i figured a lift might help with my limited mobility. Found a ford dealer with it in stock for $32 so I'm just gonna eat the extra cost

 

[BradM]

Just FYI. I installed an oil pressure sender and gauge and during my research found the Ford oil pressure spec is minimum 30psi at 1500rpm (I assume hot). Mine measures 42psi at 1500rpm and under 20psi at idle. I don't know what psi trips the OEM pressure switch.

 

[Junkyard_Mad-Scientist]

Update: switch is in, old one was full of oil. Cleaned the connector thoroughly and put a day of dielectric grease in the new connector. Tightened it to the 10ftlbs plus 180°. Double checked the oil for correct levels and fired it up. I let it idle for about 15 minutes before I left my buddies house. As soon as I put it in drive the light came back. Still went away with throttle but came back as soon as it came to idle. So now it's not sporadic but constant, every time I come to a stop it comes on and stays on until I move again. No noises from the engine bay, oil is flowing under the cap. At this point I'm going to buy a test kit and check the pressure but I'm skeptical and kind of convinced it's the pump.

 

[SHOdded]

oil pumps have not failed on any 3.5 cyclone based blocks that i am aware of, or if they have, failures are EXTREMELY rare. couldnt hurt to put in a new one once you are in there tho, keep the old one if you have room at home.

now livernois did build a custom part to improve oil flow for @bpd1151, idk how well it works, one off that i can recall.

Original 2007-2023 Ford Oil Pump GL3Z-6C639-A | Levittown Ford Parts

2007-2023 Ford part # GL3Z-6C639-A - Oil Pump

parts.levittownfordparts.com

fits a wide variety of applications, naturally asp or turbocharged

Client Challenge

if you want to upgrade the pump. but unless you are heavily power added, i dont see a reason for it.

 

[BradM]

Since the ECU controls the pump pressure, make sure that part is working. I believe the ECU looks at engine (or oil) temp and adjusts the pump pressure. Just make sure you've eliminated everything before diving into the pump.

 

[Texas Marauder]

or more accurately the chain/tensioner since that is what drives the georotor-based oil pump. oil pumps have not failed on any 3.5 cyclone based blocks that i am aware of, or if they have, failures are EXTREMELY rare. couldnt hurt to put in a new one once you are in there tho, keep the old one if you have room at home.

The oil pump is not driven by the chain. The crankshaft passes thru the oil pump to drive it directly. Chain must be removed to change the oil pump.

 

[SHOdded]

edited post thanks for the reminder!

 

[Texas Marauder]

Since the ECU controls the pump pressure, make sure that part is working. I believe the ECU looks at engine (or oil) temp and adjusts the pump pressure. Just make sure you've eliminated everything before diving into the pump.

There is no electrical connection to the oil pump. The ECU does nothing to control oil pressure on this engine.