I have an '01 Expedition with the 5.4L. In the cold weather, I have noticed a whine from the engine when at idle and also when you take your foot off the gas while driving. When you give it gas, the noise disappears, only to come right back when you let off the gas. The car idles around 200 RPMs higher when the noise is there than it normally does. It is a high pitched whine that you can hear both inside and outside, definitely coming from the motor itself, not the belt assembly. Also! Over the last week, my oil pressure guage has a tendancy (rarely so far) to zero out while I am driving, also causing the oil light to come on. Any ideas on that one? Scares the hell out of you, but the oil level is fine and the car doesn't behave any differently. Anyone else had either of these issues? Let me know.

 

The whine sounds like a vacuum leak. I would check the PCV hose assembly. These are known to fail.
The oil pressure thing could just be a faulty sending unit. If you are not getting any unusual knocking or lifter ticking, then I would change the sending unit first.
Jimmy

 

Jimmy,

I think the PCV replacement is a great idea. I had already decided to try that, you just confirmed it for me. My Expedition has always had a slight ticking like the lifters are going out on it (sounds very much like an exhaust leak right at the firewall) but the oil guage only just began to drop off to zero in the last couple of weeks. I wondered if it might be related to the cold weather.?. I have had four different shops (two dealers and two mechanic shops) look at the ticking. One Ford dealer said to ignore it, the other said it was a bad crankshaft and wanted to replace the engine at a cost of $3400. The two mechanics said that it was too difficult to locate precisely, just to ignore it or trade the vehicle, so you can tell I am really frustrated. I love my Expo, I just began to have these little problems crop up since the weather turned cold. I haven't noticed any changes in the motor or the ticking noise since the guage started falling, and performance has not been affected at all. What do you think?

 

Similiar problems . . .

Just this week I noticed very similiar problems with my 1994 F-250 (120K miles). The oil pressure guage is below the 'N' (NORMAL) on the idiot guage. I also notice a ticking (could be pinging . . . but definitely not knocking) noise from the engine. The past couple of weeks have been cold (nights in 20's days in 30's) here in Massachusetts. The oil guage scares me as I figure it will either be the oil sending unit is bad (cheap and quick) or the oil pump assembly is shot (very expensive and time consuming).

I'm bringing it in to my regular mechanic to inspect the sending unit. I'll let everyone know what I find. Any other suggestions/diagnostics from anyone out there?

 

Hi and welcome to FTE
I would replace the sending unit myself. They are only about $10 and you usually only need a 9/16" wrench to remove and instal them. 1 wire connection and it is down near the oil filter on your 94.
Jimmy

As for the ticking, it seems that some of these modular engines are having problems with the exhaust manifold studs breaking on the passenger side. This could be a small exhaust leak that you are hearing. I would go ahead and check the actual pressure with a mechanical gauge to be safe, then replace the sending unit if all is ok with the pressure.
Jimmy

 

Not sure what the ticking noise is but I certainly would like to rule out the exhaust manifold as I had both of mine replaced (both were cracked) just a few months ago. Not Cheap!!

I also found some good posts in the Heavy/Super duty forum regarding low oil pressure. Basically some folks were saying that the combination of cold weather and the type of oil they were using caused the sending unit not to work properly or cause mis-reads.

https://www.ford-trucks.com/forums/s...hreadid=179512

I'll let you know if replacing the sending unit fixes the problem. I was going to bring the truck into my mechanic; however, you mentioned that it is the part is only $10. Is it a hard job for a novice do it yourselfer? Not sure if it is covered in the generic Haynes manual.

 

It's not hard, it is threaded like a bolt, so just unscrew the old one, put a little thread sealer on the new one( make sure that you don't get any on the bottom , below the threads, there is a small hole in the bottom for oil to enter, and thread the new one back in. Plug the wire back up and start it up.
Check for leaks after you start it.
It shouldn't take but about 15min.
Jimmy

 

FIXED!!!

I finally replaced the sending unit. While removing the old unit it basically crumbled and came out in a couple of pieces. After replacing it I started it up and the oil pressure immediately went up to about the 2/3 reading. Talk about relief. I was hoping it was not the oil pump b/c from what I've heard you basically have to remove the engine to service it.

In any case it was a simiple solution, inexpensive, and the engine seems fine again at 120,000 miles.

 

Glad you got an easy fix.
Happy Holidays, Jimmy

 

I also had the whining noise in cold weather. When idling or driving at a constant speed I would get the noise. Give it some gas or let up and it would go away. Had this since day one when I got my 94 town. Just had the belt changed and the shop called me up and said the belt tension pully asmbly was shot. OK, change it. Noise gone.

The noise was like a long hooting noise............

For what its worth.........................