Oil pressure problem ?

[davem]

My 2001 Explorer XLT V-6 has 127,000 miles on it. My son has driven it the last month or so and now that he's back in college, I'm driving it again.

I noticed the 'Check Gas Cap' light was on and my son said it came on and did not come on right after fueling up (I'm not sure how many miles/days later before it came on). I'm not sure if the dash also had the red 'check guage' light or not, but part of me thinks the 'check guage' was lit, and I might have assumed it was related to the 'check gas cap', but I kinda think that would be redundant.

Jump ahead to today ................. its 20 F and I went out to move the Explorer so I could plow the driveway. It had the normal rough idle/cold start. After I fiinally backed out of the driveway, I noticed the 'check guage' light and looked at the oil pressure guage which was at 'none'. When I drove it a few minutes later, the idle was better (not great), and the oild pressue was back.

I'm hoping the low oil pressure was related to the rough/stumbling idle, yet in the back of my mind, I kinda recall that 'check guage' light being on for a week or two ............... sure hope it hasnt been driven for two weeks with no oil pressure. I did check the oil level - looks like I need to add a quart.

Not sure what why I'm posting, but would be interested in any comments.


Dave

 

[SoNic67]

Did you hear any deep knockings (main bearings) or loud chatter (lifters, chain tensioner)?

PS: A coleg of mine gave his son an older car to drive to school. Burning oil, so dad said "add some oil if is low".
One day son called that the car doesn't start. He drove it with the red "oil" lamp on, thinking that is like the gas light: if light is on, you can drive it till it stops, then find some money, add gas/oil and presto, ready to go. Well, he found out that was a reason why gas lamp was yellow and the oil one red.

 

[davem]

I was hoping the low pressure was related to poor idle, but I
Tried starting it again and got the same: no oil pressure.

Could it be the pressure sender? Where is that located?

Could it be the gauge itself?


I plugged in the block heater and will try it this afternoon.

Does it seem odd that I went from good oil pressure to none
So quickly? (rather than gradually)

 

[my98nnj]

It's most likely the sensor. It wouldn't run to long with no oil pressure and you would definitely here the motor making a very abnormal sound.

 

[2000StreetRod]

Sohc v6?

It's most likely the sensor. It wouldn't run to long with no oil pressure and you would definitely here the motor making a very abnormal sound.

Cold weather (20 deg F) and low oil (1 quart low) means more time after engine start before oil pressure. This is especially true if you're not using multi-weight oil.

Hopefully, you just have a bad oil pressure switch which is not that uncommon. If you have the SOHC V6 this post may help you locate the oil pressure switch: Oil pressure gauge

 

[koda2000]

if oil is too thick (believe ford suggests 5w20) it could take a few seconds for the pressure to built. 1 qt low wouldn't make a difference as the oil pump pickup would still be submerged even at 2+ qts low as long as you're on fairly level ground. pressure sender/switch is located on the engine block behind the power steering pump. if oil weight is okay it's probably the pressure sender reacting slowly. easy to change it and it's not expensive.

 

[davem]

The air temp got up to 37 F today (very warm for MN) and I plugged in the engine block heater, for good measure.

I checked the oil level today (in better light than last night) and I'd say its maybe got 1/2 to 3/4 of the way up the cross-hatch on the dipstick. So oil level seems sufficient.

I changed oil about 1000 miles ago, using 5W-30 and Motorcraft FL-1A filter, as always.

It started fine today and had the normal, immediate oil pressure.

So its certainly looking like the pressure sender. Based on pictures provided here (thanks), its buried too deep for me to attempt removal. I'm wondering if it could potentially be a filter issue ? With today's filters, bypass valves, etc, could a filter issue cause low pressure ?

I'm guessing a shop is gonna charge me a hour of labor + parts (approx $30 ?) to replace this - sound about right ?

Thanks.

 

[koda2000]

i doubt the filter would have anything to do with it, especially after only 1000 miles. it's most likely the sender. keep an eye on it for a while if you don't want to pay to change it right away. it's only the gauge. you'll know if you really don't have pressure as the lifters will start making a racket.

 

[davem]

Just posting a follow-up ...................

A shop replaced the pressure sending unit (total cost: $65) and the problem is resolved.

Thanks everyone for your help.

 

[bobflood]

Just as info: I have seen many threads on this site that indicate that the oil pressure gauge is not a real guage, where the indicator changes linearly with the actual pressure, but more of an analog idiot light. Any pressure above 5 or so PSI (?) will jump the needle to the middle section of the guage.

 

[davem]

Yeah, I know its not really a 'gauge' per se. But I could not accept driving the rig with the 'check gauge' light on and the 'gauge' showing NO pressure.

So its all good.


Time to move on/return to my 'rough idle on cold start' thread !