Guys,

I am having an oil pressure issue...I think, any input would be greatly appreciated. For the record this is the first Ranger I have used the manufacturers recomended oil viscosity rating and switched to synthetis over a year ago, I run Mobil 1 Synthetic 5/20.

Ok the last 3 mornings when I have started my truck cold the "Check Gauge" Warning Light Comes on because my Oil Pressure Gauge is not registering any oil pressure. After approximately a minute the oil pressure gauge begins to register pressure and the warning light goes off.

Ok I know the gauge is a "dummy" gauge. The weather here is relatively warm, it has been when it has done this...like 50's in the morning, so it's not like it has been extremely cold. The only other time I have seen the gauge stall for a few seconds before registering pressure is the first time I start the truck after I have changed the oil. Now once I have started the truck and go through this it will not repeat this when I start the truck through the day, it only does it on cold starts first thing in the morning after sitting all night.

Ok any insight would be greatly appreciated, for the record my truck only has 57K miles on it, the rest of the specs are in my sig -

 

Hi Waves,

You have all the symptoms of a bad oil pressure sending unit (switch). It is located behind the head on the passenger's side bank. When I changed mine, I found it was easier to go through the inner fender liner on the passenger's side to change it.

Good luck!!

 

Bob -

Thanks for the input, I am hoping that the problem lies there rather than in the oil pump or some internal engine problem. Is there a way to check or do I just have to replace it and see what happens? Would an engine diagnostics check pick this up or would it just read bad oil pressure because the gauge read that? Maybe this is just blind faith on my part but I just can't imagine an internal engine issue so early in the engines life...I know it can happen but...?? Anyway thanks agian for the input -

 

Hi Waves,

If you haven't heard any unusual valve train noises, I'm confident in saying it's the sending unit, not an oil pressure problem. It's an inexpensive part to replace, and a very common problem. This signal from the sending unit is not fed back to the PCM, so it will not show up as an error code.

 

Thanks for the explination, didn't know it was a common problem I haven't noticed it much here. Will replace soon and let you guys know how it goes -

 

I like Bobs take on this.

As Bob said, IF your not hearing any untoward engine noises, during the no oil pessure time, it's likely a misbehaving oil pressure sending unit.

If it happened just after a oil filter change & you have some start up noise, maybe something is going on with the oil filter!!!!

If you want to check the oil pressure, you could hook up a mechanical gauge, to the sending units port, on the engine block & check/monitor the pressure that way.

Some parts stores have a "loan-a-tool' program, so maybe you could loan the oil check gauge & fitting there.

Just some more thoughts to ponder.
Let us know how it goes.

 

I am planning on replacing the sending unit this weekend. For the record, this morning I started the truck the guage worked, while letting it warm up for a minute or so it went to zero, then back to normal, then to zero and back to normal again. I live less than a mile from work, it went to zero once more when I was driving down the block and then back to normal again. There are no noises or strange sounds coming from the motor. I changed the oil about a month ago, so I don't think the issue is with the filter....but you never know. Will let you guys know how it goes after replacing the sending unit -

 

I had this problem a month ago or so, but haven't had it since I changed my oil. I also use Mobil 1 5w30 with a mobil 1 filter in my 2001 B4000 4.0L. It seemed to only happen on colder mornings (30-40 degrees) but we've had a few here recently that were really cold (20 degrees) and everything worked fine.

 

I had same problem with my '99 ranger during cold weather , I change the oil sending unit, problem fix . Darrell

 

Assuming your oil level is in the crosshatch section of the stick, i agree with the other guys. You WILL hear valve train clatter if there is no oil pressure, and if you do dont drive it, shut it down.
My 2006 Harley had a similar problem, the oil light kept coming on, and turning off, but the valvetrain didn't clatter so i rode it home. I unplugged the wire going to the sending unit for the dummy light and put on a little di-electric grease on the terminal and the oil light has never come on again in 7,000 miles.

 

I had the same problem, new oil sending unit fixed it right up!

 

Ok just a little update here. After I posted thursday morning, the gauge started working normally. I opted to wait and see what it does, so far working like it's suppoesed to, fogured I will replace the sender if it starts to act up again, but so far no problem the last 4 days. Have any of you guys changed over to manual guages? Is there a reasonably affordable way to change the guage to a manual, or would the only way to get a manual gauge be to put in an extra guage so to speak? I would like to have a real gauge rather than this face dummy gauge junk -

 

Waves, sounds like maybe you'd be interested in the "Oil Pressure Gauge Conversion" that Bob Ayers did on his 3.0L.

Look in the "Tech Info" thread, atop this forums front page & scroll down to the "Misc" section for the link.

He replaced the "switch" type sender, for an older Rangers electrical "pressure" type sending unit, to cause his gauge to respond to oil pressure changes.
He didn't find the "resistor" mentioned, as it seems Ford has redone the gauge impeadence on later models, so we don't have to short out, or remove the gauge resistor.

I believe he used a sender for a 87 Ranger.

That would be easier than plumbing in & mounting a mechanical gauge.

Just an idea to ponder.

 

Hmmmm very intresting...sounds like a great idea. Will check it out later whan I am not at the office, sounds like a great idea, I really don't understand why they went to the dummy gauges....anyway thanks again for the info and suggestions.

Waves

 

After reading all of this thread I've decided to convert my idoit gauge to a functional gauge. When I do the convert, I want to monitor the oil pressure (temporary gauge installed) so I can "calibrate" my dash electronic guage. Several bits of information need to be determined for a 2002 2.3L under ideal conditions. I would suspect the lowest acceptable pressure value would be the present sending unit switch setpoint (5 or 6 psig). What is the expected nominal and highest pressures for a fresh engine operating at normal coolant temperature?