OT: generic car q--99 ford taurus and oil pressure

[ryan roopnarine]

Greetings all.

I have a 99 ford taurus with a 3l 12v v6. about 10k miles ago I had to get a headgasket replaced on it. the first oilchange after this, i had a problem (for two or three starts) where it would take between 1-1.5seconds after the engine started before the oil pressure light would go off. the oil change seemed to fix it. fast forward to now

I have about 185k miles on it, and was running a synthetic 5w20 for 6k miles. i was using the w20 instead of a 30wt oil because it reduces oil consumption in this car. about 300 miles before the oil change, i put a double dose of fuel injector cleaner into it, and drove it on the highway for about 250 miles. during the drive, in increments of 5-10 minutes, i'd shift out of overdrive and let it run at about 3500 rpm (as opposed to the normal 2300 rpm) for a total of 30 minutes. this was to try to solve a pinging problem that was re-emerging here in this wonderful florida heat. i didn't notice a delay when i stopped for gas about 100 miles before my destination. however, the next day, i found that with every cold start (temperature between 85-95 degrees outside) that it would take at least 1 second for the oil pressure light to go out. a change with 0w30 mobil 1 didn't seem to fix it. there are no other oil related issues with this car, I don't get a low oil pressure situation at idle, and the car uses about 6/10 of a quart per 6000 miles.

any guesses as to what this could be? dirty pickup screen? engine going south? am thinking that i need to swap out the pressure sensor and put a gauge on it to see what is going on, but it will be a couple of days before I can get around to doing so. thanks.

[Mr._Graybeard]

As perhaps the only other Taurus owner on this list, I feel compelled to chime in.

I know Ford has specified 5w-20 in later-model cars, but in Florida in the summer, I'd sure think about using 5w-30 and maybe even 10w-30. That could help the car pump up the oil pressure more quickly when below operating temperature.

I just went out and checked the owner's manual in the Ford. It specs 10W-30 for hot climates. That's for a 1995 model, not a '99, but I can't see what damage you'd do giving a little thicker oil a try on a 90-degree day.

[Ross]

Is your filter mounted vertically with the base down? My first thought is that the anti drainback valve is not working properly or perhaps an incorrect filter is installed. The cold start aspect reinforces this theory as it takes time for the filter to drain out, also at cold temps logic dictates that pressure should be higher.
Your oil choice and ambient temps eliminate much chance of pump cavitation at start up. We see this sometimes in the frozen north when people leave heavy summer oil in their crankcases until January.
A filter draing could cause the delay in seeing pressure to the gauge as the filter will take a few moments to refill. Also, 0wt. oil flows so easily that a lot of volume must be moved for pressure to show up. I see no reason for such a light oil in Fl. especially in a well worn engine with presumably larger bearing clearances.
A weak oil pump, excessive bearing clearance or a sticky pressure relief valve could also be at fault if there is one.
I'd try a different filter first. Then increase viscosity if this continues to be a concern.
As long as running pressure is fine and you don't rev the engine on a cold start I wouldn't worry.

[Bill R.]

As others have stated, I'd be likely to run a 5w30 instead of a 0w20 or 5w20 at your high mileage...The filter on that motor is mounted at an angle , not vertical and not horizontal so if the check valve on it has gone bad then it would drain down and take awhile to fill back up on startup. Different oil filter manufacturers use different materials for that drain back check valve, some use silicone , some use a different synthetic rubber and other cheaper materials. If the solvent from your injector cleaner ended up in the crankcase and mixed with the oil, which it does, then it may have attacked or affected the material that the drainback valve is made of and it may not be sealing anymore..... If your really worried i'd try a mobil one oil filter which has a good quality drainback valve, the purolator pure ones from pep boys are also a good quality filter... fram , i wouldnt even think about using. Mahle also is now producing a lot of oil filters for american and japanese cars in addition to the german cars and they are pretty high quality for a very cheap price. At any rate your problem is drainback, if it was a wear and pressure problem the light would flicker at idle when hot, since its only startup its the valve in the filter coupled with a very thin oil. The 5w30 in this case would drain out of the filter much slower as well.

Greetings all.

I have a 99 ford taurus with a 3l 12v v6. about 10k miles ago I had to get a headgasket replaced on it. the first oilchange after this, i had a problem (for two or three starts) where it would take between 1-1.5seconds after the engine started before the oil pressure light would go off. the oil change seemed to fix it. fast forward to now

I have about 185k miles on it, and was running a synthetic 5w20 for 6k miles. i was using the w20 instead of a 30wt oil because it reduces oil consumption in this car. about 300 miles before the oil change, i put a double dose of fuel injector cleaner into it, and drove it on the highway for about 250 miles. during the drive, in increments of 5-10 minutes, i'd shift out of overdrive and let it run at about 3500 rpm (as opposed to the normal 2300 rpm) for a total of 30 minutes. this was to try to solve a pinging problem that was re-emerging here in this wonderful florida heat. i didn't notice a delay when i stopped for gas about 100 miles before my destination. however, the next day, i found that with every cold start (temperature between 85-95 degrees outside) that it would take at least 1 second for the oil pressure light to go out. a change with 0w30 mobil 1 didn't seem to fix it. there are no other oil related issues with this car, I don't get a low oil pressure situation at idle, and the car uses about 6/10 of a quart per 6000 miles.

any guesses as to what this could be? dirty pickup screen? engine going south? am thinking that i need to swap out the pressure sensor and put a gauge on it to see what is going on, but it will be a couple of days before I can get around to doing so. thanks.

[ryan roopnarine]

Bill, I was thinking along the lines of the fuel injector cleaner making it into the crankcase because of the advanced age of the motor. The (first) mechanic that did the headgasket said something along the lines of 135 psi compression in some of the cyliners, but he was a complete POS and didn't fix it right (broke off an egr tube and left it that way too) so I take what he said with a grain of salt.

The thing is, i notice that the problem may be improving. in fact, when i park my car in the garage at school at 7.50 (ambient temp is about 80F then), i find that an hour or so later (85-90F degrees) , it doesn't do it, but if i park it out in the sun for any longer than 30 minutes, it does it. the garage has a very very slight nose down angle to it. anyhoo, i bought a relatively expensive filter and a fill of 15w40 delo. i'm a cheap bastid, and am not going to throw away a 500 mile old crankcase of 5 quarts mobil 1, so i bought a plastic box from walmart to drain it into. perhaps i'll put it into some lawnmowers or maybe even reuse it if this problem clears up. thanks all

[ryan roopnarine]

oh, and bill, if you read this again, is the pressure relief valve mounted in the oil pump? i don't have time to do it now, but in a month i'm thinking of hitting the oil pan gasket, and this car doesn't seem to have a removable/replaceable pickup. then again, if this oil pump is anything like the 3.8 (ie all the manuals say remove engine from car...) i'll leave it and let it rot.

[whiskychaser]

Seems to me that you, Bill, Ross, and Mr G have all the bases covered. So was your oil pressure within spec or was it just a duff sender unit?

[ryan roopnarine]

well that seems to shut the light off....a gallon15w40 delo diesel with a quart and a quarter of 5w30 to lighten it up a little. light is back to the way it was before, and an almost instantaneous out when warm. makes sense, though.

[ryan roopnarine]

I guess it didn't take, I'm still seeing the same thing on the first start of the day, the fatter oil just seems to make the light go quicker when the engine is still warm.

[ryan roopnarine]

over the last few days, it seems to have stopped doing this if the engine is stone cold (first start of the day) but seems to do it if it is hot and left alone for an hour or two. perhaps it is dirt related and the diesel oil is pulling it out. the behavior doesn't seem to be following any common logic about thickness and pumping.