Low Oil Pressure Light at Idle Once Oil Is Warm, Goes Away With Throttle Blip

SkidHash · April 20, 2019, 11:05:19 AM

Hello All!

This is my first real post on this forum and I'm sad that it's an "I have a problem" post, but I know this forum is the best place to get help.

Background:2013 Taurus SHO, 115k miles. I had an oil pressure switch leaking and dripping onto the exhaust, and only saw a "low oil pressure" light once, and it went away after a blink of an eye and never came back (around 3k miles ago). Got an oil change (motorcraft 5w-30 and fl500-s filter) and figured I'd replace the sensor while I was up there. Drove the car for 20 minutes on the highway, come to a stop, and the low oil pressure light comes on. Blip the throttle and it goes off again. It only does this once the car is warm and has been driving for a long time (20+ minutes). No knocks or weird noises under the hood when it does it, and according to ForScan it mostly happens when my idle RPMs drop below the "desired Idle speed" (usually 600 RPM when in drive). My idle fluctuates very slightly, 20-30 rpm at a time (both up and down). Oil level is not low, and there are no oil leaks (except for a small drip from the CAC to the TB, but a catch can will fix that and the spark plugs weren't oil fouled, so I know I'm not burning too much of it)

What I've Done So Far: I got new spark plugs, changed out the PCV valve/oil separator (oil separator didn't have much in it), got my oil pump PSI tested (15 PSI at 600RPM, 45 at 1500RPM), have tried 3 new oil pressure sensors (2 from Motorcraft, one from NAPA, currently installed), cleaned TB/TPS sensors/plugs, cleaned both MAPs, cleaned IAT sensor, got new air filter, sucked small amount of liquid out of CAC.

I don't know what to do. I can't figure out what this issue could be and it is driving me nutty. I've just been throwing money at the car and have seen no results. I know from this post (https://www.ecoboostperformanceforum.com/index.php/topic,5118.msg81237.html#msg81237) that another member has had this issue, but they didn't post their solution and haven't responded to my message yet.

Any help is appreciated, hope you're all having a great day!

Macgyver · April 20, 2019, 03:00:10 PM

So it started happening more often after the Oil sending pressure switch was swapped out.

SkidHash · April 20, 2019, 04:41:03 PM

Quote from: Macgyver on April 20, 2019, 03:00:10 PM
So it started happening more often after the Oil sending pressure switch was swapped out.

It did start happening more after the switch was swapped out, and I also switched from Penzoil to Motorcraft oil, so that might have something to do with it. I just got back from a EVAP leak test and it looks like my bov/noisemaker is leaking a lot. I'm not a mechanic, but I feel like it isn't supposed to do that

I'm heading to Home Depot to get some plumbing caps to cap it off and see if that fixes my idle problem, and will report back with any findings!

ZSHO · April 20, 2019, 06:15:58 PM

I was curious if your BOV R VTA! Due add any Current Mods to your signature so we can assist you better! TIA. Z

SkidHash · April 20, 2019, 10:10:02 PM

Quote from: ZSHO on April 20, 2019, 06:15:58 PM
I was curious if your BOV R VTA! Due add any Current Mods to your signature so we can assist you better! TIA. Z

My noisemaker has officially been eliminated, and wow! It feels like a whole new car. The acceleration is instant, and the car doesn't stumble through even a steep uphill pull. Absolutely night and day. Did it blow off two times because I didn't tighten it enough? Sure did, but now that bad boy is clamped on there (It was a 1.5" plumbing cap from Home Depot, $3.19).

The light is still coming on, but wow the car is so much better. I haven't VTA'd anything else, but I will once I get this whole "low oil pressure" thing figured out. I can't figure out what is causing this still, so I might have to bite the bullet and take it to Ford. The mechanic today (a new one, and wow did he do a lot more troublehshooting than the last) thought that the boost leak from the blowoff valve was the culprit, but I guess not. I'm going to fill her up tomorrow and run some Barryman's through it. I just can't think of what would be causing my 10-20 rpm fluctuations at idle. Clogged injectors? Misfiring spark plug? Throttlebody? This problem has stumped me, so I appreciate all you guys offering your thoughts! I'll keep you all updated with what happens, I can't wait to get this car back to perfect!

SHOdded · April 21, 2019, 02:18:12 AM

At least a lot of other problems are getting figured out along the way, LOL. Have Ford run a power balance test for sure. Once they get the engine on a scope, it may be self-evident. Maybe it is a crank or cam position sensor ...

SkidHash · April 21, 2019, 10:12:50 AM

Quote from: SHOdded on April 21, 2019, 02:18:12 AM
At least a lot of other problems are getting figured out along the way, LOL. Have Ford run a power balance test for sure. Once they get the engine on a scope, it may be self-evident. Maybe it is a crank or cam position sensor ...

That's the best way to look at it! I'm replacing parts that would have needed to be done eventually, so I'm not too upset about throwing money at it. I'll call Ford tomorrow and see what they can do for me, but in the meantime I'm going to drive my car and have a lot of fun with it. The best part about Missouri: long and straight highways with basically no traffic or police. The best way to celebrate Easter! I'll update when I find something new!

SHOdded · April 21, 2019, 10:27:29 AM

Shhhh. Everyone might move there. LOL

SkidHash · April 23, 2019, 05:36:24 PM

Update time.

Cracked and took it to Ford yesterday. They got the car around 2 pm and immediately started working on it. Kept the car overnight and were still working on it until about noon today. Called me and told me that they could not find a single thing wrong with the car except that the oil pressure at idle while in drive "sometimes drops .2 PSI below 10, which is the minimum". Told me to put 10w30 non-synthetic in it and that it "would fix the issue", so I had them change the oil that I just put in it last week (Motorcraft 5w-30) and went on my way (after paying $200). Get 5 miles away, come to a stop light, light comes back on.

Call my service tech again and tell him that the light came back on. His response? "Nothing we can do about it now, you'll need a new engine I guess". When I asked why I would need a new engine since they just told me that there was nothing wrong with my car, he said "Well, replacing the oil pump will cost you about 75% of the cost of a new engine, so you might as well just pay a little extra and get a whole new engine". I know for a fact that changing an oil pump does not cost $6k. I also know that all they have to do is raise the idle of my car by 100 RPM (so it idles at 700) and the issue is fixed. Seems like there's a good reason that they have the nickname "stealership".

Don't know what to do at this point. I'd rather not spend $1500-2000 to replace an oil pump, especially not for temporary .2 PSI drops. Any advice, tips, or thoughts?

I'd rather not sell the car, but it's not worth putting the money into it just for .2 PSI. If the pump was 3-5 PSI low? Then it's worth it. But .2? I'll pass on that.

SHOdded · April 23, 2019, 06:14:36 PM

Not 6K, but somewhere between 1.5 and 2K at an independent shop, including the rest of the components behind the main/timing cover.

glock-coma · April 23, 2019, 09:11:23 PM

I know with the sct x4 tuner you can adjust the idle.
You can probably find one used for around $200

Macgyver · April 23, 2019, 09:16:55 PM

Yup.

1. Up the Idle.

2. Get that Dino Oil outta there and put synthetic back in.

3. Drive it like ya stole it.

SkidHash · April 23, 2019, 10:40:59 PM

Quote from: glock-coma on April 23, 2019, 09:11:23 PM
I know with the sct x4 tuner you can adjust the idle.
You can probably find one used for around $200

Can I just pick up any sct x4 tuner? I see most of them specify a specific vehicle, but if I can pick up any tuner and have it work with my car (if it's unmarried, of course), then it looks like there are plenty for about $150!

SkidHash · April 23, 2019, 10:45:11 PM

Quote from: Macgyver on April 23, 2019, 09:16:55 PM
Yup.

1. Up the Idle.

2. Get that Dino Oil outta there and put synthetic back in.

3. Drive it like ya stole it.

I have a feeling I know the answer to this question, but I'm going to ask it anyways: upping the idle is just a temporary fix, right? If I'm .2 PSI low at idle, will that continue to gradually get worse? Is there anything that I can do to stop that?

Also, should I stick with the 10w30 that they put in there but switch it to synthetic? Do you know why they would have told me to stop using synthetic in it? I'm happy to go back to synthetic, I'm just trying to follow instructions for the first time in my life

I appreciate you guys adding your thoughts and tips!

SkidHash · April 23, 2019, 10:53:49 PM

Quote from: Macgyver on April 23, 2019, 09:16:55 PM
Yup.

1. Up the Idle.

2. Get that Dino Oil outta there and put synthetic back in.

3. Drive it like ya stole it.

I should also say that my idle in drive likes to fluctuate slightly; you can't really see it in the tach, but when I have an OBD scanner hooked up to it and have ForScan open on my phone, I can see the idle jumping 20-30 rpm up and down. Usually when it goes down below the "desired idle speed", oil light comes on. No air leaks or anything (had the car smoke tested, found that the noisemaker was leaking so I capped it off), so I don't know what would cause it. Could the tuner help at all with figuring out a root cause or fixing the problem? I'm more than happy to throw a few hundred dollars at it, especially if it could potentially save me from a multiple thousand dollar repair bill