Duratec 3.0 Oil light flickering at hot idle

S

So1911

Joined
Dec 12, 2013
Messages
13
Location
US
2004 Mazda MPV, 150k miles, Mobil 1 5w30. 3.0 ford duratec V6

The other day my wife mentioned that the oil light was flickering. I went and checked the level, it was very, very low, so low I was worried about oil consumption. I found a broken pcv hose and replaced that and the pcv valve. No luck, same oil light flickering at hot idle.

After some more research, I replaced the oil pressure switch (napa/echlin), went from a purolator pureone to a wix filter, and this time used castrol gtx 5w30. I noticed that the oil pressure switch connector had oil inside of it, indicating the switch was in fact bad. Cleaned it out with contact cleaner. No change....., oil light flickering at hot idle.

Any suggestions? I guess my next step is going to be buying an oil pressure gauge try and get an accurate reading, however the light only comes on at hot idle. And there is NO WAY to attach a pressure gauge to the port while the motor is anything but stone cold.

In the back of my mind I'm wondering if running it low on oil has caused this. I would guess it was a good 2 quarts low, maybe more.
 
Yup, you won't know where you stand until you establish what the pressure reading actually is. Once that is confirmed, post back your results.
 
Originally Posted by OVERKILL
Yup, you won't know where you stand until you establish what the pressure reading actually is. Once that is confirmed, post back your results.

+1 At this point all anyone can do is guess.
 
The new oil pressure switch would give me some degree of confidence that the light is genuine. They usually trigger at 4 PSI or so. Hot idle is when the pressure is lowest.

Flickering, or an actual 4 PSI, at hot idle suggests worn bottom end bearings (mains, and perhaps rods). If this reading is accurate, and a gauge will tell you, then you have two choices:

Put in a much thicker oil and hope for the best.

Replace the Rod and Main bearings.

Most engines allow you access to the bearings through the oil pain. It's not a killer job, and can be done in a few hours. The real question is the conditions of the journals themselves. You may be able to save this if the journals are not significantly worn.

So, first, gauge. If needed, thicker oil. If that doesn't work, new bearings.

Good luck.
 
Last edited:
Originally Posted by So1911


In the back of my mind I'm wondering if running it low on oil has caused this. I would guess it was a good 2 quarts low, maybe more.

Sure could have. May have wiped out the cam or crank bearings being that low. If your mechanical oil pressure guage shows low pressure it needs a rebuild. You can try a thicker oil like 20w50 for now.
 
new shells will allow the current pump to acheive acceptable pressure. a higher volume pump will acheive acceptablee pressure with the worn shells.

in future keep on top of maintenance and this wont happen.
 
Isn't oil light flickering, which signals that oil level is low is an oil level sensor issue and not oil pressure sensor issue? If the oil is correct in dipstick then your oil level sensor/its electrical connection is bad
 
Last edited:
The 3.0L Duratec is fairly durable, even with that low of oil I wouldn't assume the engine is toast. I've seen them that low in work Escape's numerous times. Try the mechanical gauge and go from there.
 
Originally Posted by vivaUkraine
Isn't oil light flickering, which signals that oil level is low is an oil level sensor issue and not oil pressure sensor issue? If the oil is correct in dipstick then your oil level sensor/its electrical connection is bad


It's a pressure light, not a level light.
 
I'm going to second, third and forth the mechanical oil pressure gauge recommendation. Once the reading is confirmed, you will know where you stand.
 
Thanks all. I'm going to buy a HF pressure gauge and test it this weekend. I will report back.
 
Originally Posted by So1911
Thanks all. I'm going to buy a HF pressure gauge and test it this weekend. I will report back.

Do they sell an gauge? I would grab one @ Autozone or Orileys instead.
 
Okay. Cold start idle, 91 psi.

Let it idle until warm with ac on, pressure went down to 19 psi.

Drove around block, the hose for the gauge burst a pinhole, after that 11 psi at idle.

I don't think that's all that low? From what I've read the pressure sensors trigger at 5 psi? I guess I'll pull the Napa sensor and buy one from Mazda.
 
From reading on other forums the oil pressure spec is 11psi either at hot idle, or hot and 1500rpm (not clear). So I would say you are fine, and probably got a bad replacement switch. Running a thicker oil will probably raise the pressure enough to stop the flickering, but I don't think there is any harm done by running it like it is. This seems to be a somewhat common complaint with the engine you have...
 
Originally Posted by So1911
Any thoughts on the engine oil restore stuff? Is pressure low enough to warrant it? https://www.restoreusa.com/index.php



No. That's a bandaid for an engine with buggered up cylinders and epic amounts of blowby (and thus consumption). Sounds like you just got a bad switch.
 
You must log in or register to reply here.

Similar threads

I
2012 Yukon headlights flicker on acceleration
2
Replies
21
Views
2K
i6pwr
C
Oil change resolved hot idle lower oil pressure., why?
2 3
Replies
53
Views
4K
wlk
T
  • Question
1994 honda accord lx auto stalling.
Replies
9
Views
375
Taseku
M
2012 Honda Fit Sport is acting up
2
Replies
23
Views
972
M1Accord
J
2015 Jeep Wrangler 3.6 V6 Low Oil Pressure
2
Replies
32
Views
3K
350Rocket
Back
Top