5w20 to 0w20, low oil pressure

[ZeeOSix]

Originally Posted by Silver
I wonder if these instances point towards not-so-great internal tolerances, or is the 0w just too thin?

I guess I'll look for a 0w or 5w20 with a 100C visc of 8.9 or better. Or maybe I should use a 5w30 like this engine was spec'd for in earlier years? I sure did like the Magnatec. The engine is SO quiet and mileage is already showing a good jump.


What's the KV100 and HTHS of both oils?

 

[dwendt44]

That same engine spec'd 5W-30 the year before. Nothing was changed
internally. Run 5W-30 and sleep easy.
I've been running that in my Sable for years, no problems.
175,000 miles.

 

[StevieC]

Originally Posted by dwendt44
That same engine spec'd 5W-30 the year before. Nothing was changed
internally. Run 5W-30 and sleep easy.
I've been running that in my Sable for years, no problems.
175,000 miles.

And if his low oil pressure sender is defective and it's not replaced for the sake of running a thicker oil that masks the senders true problem and he develops an oil leak what happens if the sender that was defective and warning him then, doesn't warn him of a future problem because now it's not functioning at all later on and gives him the falsity that oil pressure isn't the concern meanwhile the sump is dry?
(Usually when they fail the light will come on, however I have seen them fail and the light doesn't come on)

Sorry... He should verify the problem and fix the problem. Then experiment with different oil if you want to but don't use oil or additives to mask a problem.

Now the op may not have access to a gauge to check the pressure so in this case with the part being really cheap I would replace the sending unit first assuming the replacement part is good out of the box.

 

[RF Overlord]

@JohnnyJohnson: LMAO at that sign...it's so true!

If that Taurus is like the rest of Ford's product of that time, the oil light switch is set for approx 6 lbs. It's possible that one oil keeps the pressure just barely high enough not to trigger the light, while the other is just low enough to close the switch. I agree that the first order of business is to verify the actual pressure.

 

[Tdbo]

I'd run a 5W30 in it and call it a day.
As a matter of fact, that's what I did with my 2000 Taurus with the 3.0 Vulcan that I bought new and put 275K on.

 

[PandaBear]

0w20 and 5w20 will be very close at hot idle, so it can't really be the oil.

You sure you tighten the filter and drain plug correctly? Is your oil level correct? If they are fine check the oil sender like everyone said.

 

[Silver]

I appreciate all the comments. I think they all have merit.

I didn't want to muddy up the waters but the oil pressure sensor was replaced a few months back when the light was flickering and immediately the light stopped coming on. It is actually a common failure on these cars. Having a new sensor and the oil change immediately preceding the light this time make me assume it's oil related.

I don't want this car to take a penny more from me than it needs to be maintained. I think I'll run this 0w20 a full OCI, maybe a thick additive, then go to a 5w20 or 5w30.

The truth is if the engine has sloppy bearings or something I'm not fixing it so the band aid solutions are all it's getting

 

[SwampSurvivor]

Very common. My low mileage 01 Ford Taurus had that engine and was spec'd for 5w-20. It would always light the oil pressure light at warm idle on 5w-20. They didn't make any internal engine changes from when the engine was originally spec'd for 5w-20.

Still , there should be enough fudge room for thinner oil without setting oil pressure lights.

 

[Treadstone]

Maybe he has a low oil pressure light because he is running a W20 in an engine spec'd for a W30? Seems to me the first course of action is to put the correct spec and weight oil in it, then go from there.

 

[Linctex]

Originally Posted by demarpaint
I would also confirm oil pressure with a mechanical oil pressure gauge to be certain there are no engine problems.


or a blocked/plugged pickup screen

 

[javacontour]

If you are going to do some "testing" with the benefit of an actual mechanical oil pressure gauge to test, might as well look at the oil filter situation as well. Are you doing anything out of the ordinary with respect to the oil filter?

Oh, and I see above a question about the pickup screen. Has this always been YOUR car with a known good maintenance history? Wait, I see you've had this for 7k miles.

Okay, I think I'd get an honest to goodness oil pressure check done as this seems to be a "new to you" car.

I think you need to know where you are before you invest any serious money into this 17 year old machine.

 

[Silver]

This year was spec'd for 5w20, all -earlier- models same engine was spec'd for 5w30. Insert your Ford conspiracy/cafe arguments here

I replaced the oil pan gasket shortly after I got it because it was leaking. The pickup looked fine and no debris or even sludge in the pan.

 

[StevieC]

Originally Posted by Silver
This year was spec'd for 5w20, all -earlier- models same engine was spec'd for 5w30. Insert your Ford conspiracy/cafe arguments here

I replaced the oil pan gasket shortly after I got it because it was leaking. The pickup looked fine and no debris or even sludge in the pan.

I'd still put money on the sensor being the issue.

 

[SwampSurvivor]

Originally Posted by Treadstone
Maybe he has a low oil pressure light because he is running a W20 in an engine spec'd for a W30? Seems to me the first course of action is to put the correct spec and weight oil in it, then go from there.


For the 2001MY and on, Ford spec'd 5w-20 for this engine

 

[javacontour]

I think he said he replaced it already.

Originally Posted by Silver

I didn't want to muddy up the waters but the oil pressure sensor was replaced a few months back when the light was flickering and immediately the light stopped coming on. It is actually a common failure on these cars. Having a new sensor and the oil change immediately preceding the light this time make me assume it's oil related.


I think he also said he's only had the car for 7k miles.

Happened immediately after an oil change and the sensor was changed leads one to believe it's one of the following:

1. Big coincidence. It's just worn out enough to suddenly show up at this time.
2. Something wrong with the oil and/or filter choice.
3. It was sold with 15W40 or 20W50 in it to get it sold and now that it's full of something closer to the specification, the real mechanical condition is evident.

My money is on the last one.

Why? OP has had the car a short time and says there is a significant fuel economy increase with the 0W20 oil. So it was filled up with thick oil/STP/Motor Honey to get it sold, which doesn't help fuel economy.

None of us will know until there is actual mechanical diagnosis...

Originally Posted by StevieC
Originally Posted by Silver
This year was spec'd for 5w20, all -earlier- models same engine was spec'd for 5w30. Insert your Ford conspiracy/cafe arguments here

I replaced the oil pan gasket shortly after I got it because it was leaking. The pickup looked fine and no debris or even sludge in the pan.

I'd still put money on the sensor being the issue.

 

[SwampSurvivor]

There was a TSB on these cars when they were new that the oil pressure light would flicker at hot idle while running spec'd 5w-20

 

[Silver]

Originally Posted by javacontour
I think he said he replaced it already.

3. It was sold with 15W40 or 20W50 in it to get it sold and now that it's full of something closer to the specification, the real mechanical condition is evident.

My money is on the last one.

Why? OP has had the car a short time and says there is a significant fuel economy increase with the 0W20 oil. So it was filled up with thick oil/STP/Motor Honey to get it sold, which doesn't help fuel economy.



A more detailed timeline:

I bought the car with 97k.
Around 98k noticed oil light flicker at hot idle.
Changed oil from whatever came in it to Valvoline Maxlife 5w20.
Oil light still came on.
Replaced oil pressure sender.
Light never came back on.
Around 100k changed oil pan gasket. Pan looked good, no signs of any debris or sludge.
Also changed pcv valve with MC oem, just as a precaution.
Changed oil to 0w20 at 104k.
120 miles later oil light flickers at hot idle after I run into chik fil a for a biscuit.
I ordered a chicken, egg and cheese biscuit with a large half and half tea with lemon.

 

[javacontour]

Quote



I ordered a chicken, egg and cheese biscuit with a large half and half tea with lemon.



With or without ice? That is key to solving your issue.

 

[OVERKILL]

Originally Posted by Treadstone
Maybe he has a low oil pressure light because he is running a W20 in an engine spec'd for a W30? Seems to me the first course of action is to put the correct spec and weight oil in it, then go from there.


If the oil pressure light is coming on at 6psi, then he's got other issues here. My high mileage 302 still had excellent oil pressure with 0w-20 in it (close to 30psi) hot at idle. It was mid 30's with a 0w-40.

The difference in pressure between an ILSAC 5w-30 and 5w-20/0w-20 will be minuscule, like 1 or 2 psi. So if it's touching 6psi with the 20, it's at like a whopping 7 or 8 with a 5w-30. That's not an engine that is mechanically healthy.

 

[OVERKILL]

Originally Posted by Silver
Originally Posted by javacontour
I think he said he replaced it already.

3. It was sold with 15W40 or 20W50 in it to get it sold and now that it's full of something closer to the specification, the real mechanical condition is evident.

My money is on the last one.

Why? OP has had the car a short time and says there is a significant fuel economy increase with the 0W20 oil. So it was filled up with thick oil/STP/Motor Honey to get it sold, which doesn't help fuel economy.



A more detailed timeline:

I bought the car with 97k.
Around 98k noticed oil light flicker at hot idle.
Changed oil from whatever came in it to Valvoline Maxlife 5w20.
Oil light still came on.
Replaced oil pressure sender.
Light never came back on.
Around 100k changed oil pan gasket. Pan looked good, no signs of any debris or sludge.
Also changed pcv valve with MC oem, just as a precaution.
Changed oil to 0w20 at 104k.
120 miles later oil light flickers at hot idle after I run into chik fil a for a biscuit.
I ordered a chicken, egg and cheese biscuit with a large half and half tea with lemon.



Find somebody with a gauge if you don't have one and check the pressure. That'll put an end to all the guessing and at least give you an idea as to where you stand.