Two questions

[crossman]

I have a '91 Explorer Sport and have two little problems with it right now:

1. The oil pressure gauge on the dash has been going crazy lately. Up until a few months ago, I would start up the Ex and the needle would sit right in the middle of the gauge and stay there. Now, the needle sits a little below halfway on the gauge and while I'm driving it will drop down even more, then go back up to just below halfway again. It is constantly doing that, no matter what speed I'm going. I am using 5w-30 Valvoline Max Life oil and the motor isn't using any oil at all. Could someone explain why this is doing that? Could it be the oil pump?

2. When I have my Ex running, the voltage gauge needle sits around the "AL" in normal on the gauge. When at idle, the needle will start flickering back and forth, but as soon as I bring it up from idle, it will settle back to the "AL" on the gauge. Also, when I'm going on long trips on the highway, the needle will creep up to almost the 18 on the gauge. What is causing this? I put a new alternator in the Ex about a year ago. Could this be a bad ground somewhere? Thanks in advance for any help.

 

[TSTONE]

before you get deluged with posts on this topic, try doing a search(upper right) on "fake oil gauge" there was a huge debate/discussion bout this around a month ago.
probably will help to explain alot (maybe?)

 

[crossman]

Thanks for the tip. Looks like my gague is doing what everyone else's is doing. When I get a chance, I'll have to see if the sending unit is plugged up like other's have. It's nice to have a site where I can get good answers on things.

 

[yob_yeknom]

Sounds like the sending unit for the oil pressure guage is going bad. The gauge is fake, either off or on, so there shouldn't be any fluctuation. Let me us know if replacing the sending unit doesn't fix the problem.

The voltager guage should drop some at idle, since the alternator isn't spinning as fast as when at higher RPM's and isn't creating as much current. That part is normal. The going up way too high on long trips is not normal though. I suspect the voltage regulator is not keeping the voltage down as it should and is in need of replacing.

 

[crossman]

The oil needle just started doing this a few months ago, around the same time that my voltage gauge needle starting flickering at idle and also climbing when going on long trips. Could this possibly be a bad ground somewhere?

 

[TPLYNCH]

I'd have to agree with John - Alternator and the integral voltage regulator. Search for Voltage regulator to get more info.... the alternator may still be good, but the regulator goes bad.

 

[crossman]

Ok, I was thinking of changing the voltage regulator to see if that helps, since the alternator isn't that old. How much does a voltage regulator cost? I was looking through Parts America's online catalog and saw some for around $15 and then some for above $70. What are the differences in these to compensate for the difference in price? Thanks for all the help!

 

[410Fortune]

Since your X is a 91 you most likely have an internal voltage regulator in the alternator.

I suggest taking the alternator back and have it tested.
The internal regulator cannot be replaced without dismantiling the alternator.

Almost all alternators come with a lifetime warranty (at least I wouldnt buy one that doesnt!) so keep that receipt.