Hello!

I recently purchased an 89' Ford Ranger XLT. It has had extensive work done on it. It has a rebuilt transmission, new clutch, high-power air filter, and I just replaced the gas filter because it was having a bit of a power issue.

Overall it seems to be a great truck and I really love it. However there is one thing that is worrying me a little. Usually the oil pressure is reading on the low side, just about on the first "N" in Normal. Today for the first time it was actually running just below the "N" and this started to really worry me. Sometimes it stays right in the middle where it *should?* be. I'm curious why it varies? And I'm also looking for advice on where I can look for problems. I don't have a lot of money so I am hoping it's something I can fix myself. If it needs to be fixed. Possibly the gauge is incorrect? I'm guessing its not...

I always check my oil and it barely leaks. I have to put maybe half a quart per month to keep the oil at the right level.

The only other issue I'm having with it is it does not go up hills without losing speed in 5'th gear and I often have to down shift. With a v6 2.9L this seems a little strange. There was an air hose that was supposed to be connected to to the air filter that was missing. I replaced that today and also a VERY clogged gas filter. Replacing the gas filter helped a lot, but it still doesn't seem to have as much power as it should.

Any help is greatly apreciated as I am worried that my truck might be slowly being damaged by the low oil pressure / power issues. I have to drive it for work so this is crucial to my life.

Thank you very much for taking the time to read this!

 

In my personal experience, Ford oil pressure gauges are not very accurate or consistent. If you are very concerned, I would buy a good aftermarket gauge. I have an '85, that has been in the family since it was new. The gauge has always read low and some days it reads almost as low as it can read.

 

You oil pressure sending unit is a resistor type. That means that when the oil pressure is applied to the sending unit, it's basically ON or OFF. You could install a new sending unit in the block to see if the resistance in the new sending unit gives a different reading.

What kind of hills are you talking about and at what speed are you taking the hill that requires the down-shift? I mean, your 2.9 only had 140HP when new and now it's 24 years old. Heck, My 88 Ranger S/C 4x4 with the 2.9 5-Speed required me to down-shift on certain hills even when new (Wish I still had it).

Try cleaning the IAC & MAF sensor along with running some injector cleaner thru the system.

What about new plugs, cap, rotor and wires?

You could also do a COLD and HOT compression check of the cylinders to see what the reading are (power loss due to worn rings, valve seats)