Last night, I was driving my 2002 Ranger Edge 2wd 3.0 when the oil pressure gauge quit, the engine started knocking and then I killed it. I trailered it back home, unloaded it, and am scared to start it. The truck has $191,000 miles. We have meticulously serviced it. The oil pressure gauge has always jumped around during the 5 years we have had the truck. A ford mechanic told us that was common and was most likely the sending unit. We have never had any kind of mechanical issue with it before.

I am not sure where to even begin with this problem. Any input is appreciated.

 

Check the oil first, something may have happened and you lost all the oil
Could be oil filter blew out, road debris hit the pan and made a hole, Main seal blew .............???

If oil is full:
Pull off the CAM sensor, back of the engine at the top

Unplug the coil pack's 4 wire connector, so a No Start

Have someone crank the engine over and watch the inside of Cam sensor synchro tower to see if its spinning

Cam synchro looks like this: https://therangerstation.com/tech_li...n_sensor.shtml

It has a Drive gear that is turned by the Cam Shaft, and at the bottom a rod runs down to drive the oil pump in the oil pan

If the synchro is turning then oil pump is as well, you can remove the oil filter and put a pan below it, then crank engine and oil should flow out and into the pan

If synchro is not turning then the Drive Gear's roll pin may have sheared off or come out, pull out the synchro tower to check why its not turning



Yes, oil pressure gauge does that up and down thing, not uncommon when a pressure SWITCH is used, and yes most likely the sender needed replacing but that would have nothing to do with actual loss of oil pressure

 

Thabk you for the detailed reply. Oil is full. That's the first thing I checked. I had to start it again to get it on the trailer. Trailer didnt have a winch. Hopefully I didnt hurt it.

I will check the rest this weekend and report back. Hopefully nothing too major. It's been a great little truck.

 

If it lost all oil pressure then the lifters would have "ticked" very loud when you loaded it on the trailer

 

It was pretty loudmouth. Not a knocking but definitely sounded like something was loose.

 

Loud... auto correct.

Now that I thg ink about it I did replace the cam synchronize last year. Would that matter?

The OEM started chirping really bad.

 

Yes, new just means NEVER tested, so........................

Anyway unplug coil pack and see if cam sensor is turn while cranking engine

 

My poor ranger has been sitting. Ive been slammed at work then loads of things to do at home due to the holidays. I didnt want you guys to think I had forgotten to post updates.

 

Checked it today

Oil is full. Needs to be changed.

the cam sync is spinning when the engine is turned over. No noise. It actually sounds smooth.

I removed the oil filter and oil is coming out when its turned over.

Could a bad oil pressure sending unit cause actual loss of oil pressure? Intermittent problem of some type? I'm perplexed.

 

No, not unless it came unscrewed and oil was pumping out of the open hole which you would notice as a big puddle on the ground
Its behind the passenger side head on the block

Doesn't read like any normal failure

Oil pump is pumping some oil, it could be the pumps pressure regulator failed in some way, but its a pretty simple setup, a ball in a hole with a spring holding it in place, if oil pressure in the pump gets too high the ball/spring is push back and oil flows out and back into the pan, it is held in place by a bolt and I guess that bolt could come unscrewed and fall out, so ball and spring would also fall out and very low oil flow and pressure

 

Thanks for the response. I'm going to buy a new oil pressure sending unit tomorrow. It wasn't leaking

Could a clogged oil filter cause low oil pressure?

 

I thought most oil filters have a built in bypass for such situations. Clogged oil pickup could drop oil pressure.

 

This truck calls for 5w20. If I'm running an oil enhancer like Lucas stabiliser can it keep the oil too think and perhaps cause cavitation in the oil pan? It was a cold day and the truck had been sitting for a couple of weeks when this happened. Just grasping.

 

Oh yeah that oil is too thick and will starve the rod and main bearings fast, plus it will not go through the oil filter

 

???
A 5W oil is too thick and will not go through the filter?

 

oh sorry i thought you were using Lucas

 

I did add a bit of Lucas stabilizer at the last oil change. Maybe half of what it called for.

 

Everything is back together. Starts right up but has a horrible knocking noise. I didnt leave it on long enough to see if there was pressure on the guage.

 

You can pull one spark plug wire at a time and start engine, when/if knock gets quieter then its a connecting rod knock

A connecting rod knock noise is from the gap thats formed when rod bearing fails, when cylinder fires that gap is closed rapidly and makes that Knock noise

But it reads like thats what it is
You can get a used 1998-2008 Ranger or Mazda B3000 3.0l engine as a direct swap, 3.0l Vulcan engine was discontinued after 2008

 

Are these engines worth rebuilding or cheaper to just do a new long block?

 

You would need to price it out locally, machine shops can quote you, and they can also quote you on an exchange short or long block for local pickup

A used 3.0l Vulcan is not a bad gamble, your current issue aside, they were very reliable engines, so usual end of life was in an accident not engine failure

 

Don't use Mabco engine long/short blocks if it comes down to that...if i had to go through it again i would have had the crank reground ...piston rings...valve job/seats...or new heads at 160k my rod bearings were starting to show signs of wear...if you can do it yourself go for it .... different thing with my 3.0 i had oil mixing with the coolant/ cracks in heads/v seats... (problem was the block)..so went with Mabco short block... new heads (not Mabco)...big mistake with there short block but that's another story....going used engine for me was a gamble as they are prone to have valve seat problems and high miles, price range from $800 to $1900...short block or long you will spend close to 3k when all done...

 

I had a buddy look at it who is a life long mechanic. At least two rod bearings gone and mains most likely as well. He said it seems like the pressure regulator failed as RonD suggested.

My next question is this... will any 3.0 vulcan swap out? Such as from a Tarus or Sable? I Know I will have to change the intake and fuel system, but it appears these engines are pretty much all the same. I found some used 3.0 Vulcan engines from 04-05 Tarus and Sables. My friend says they should swap our as long as I put all of my accessories and intake on the new one.

Thoughts? Guidance?

 

Also if I use my existing intake and accessories will anything need to be reprogrammed?

 

You need to change the head gaskets if you get a 3.0l Vulcan from a car, cars have engine mounted sideways so coolant flow thru the heads is different, end to end, Rangers flow is front>back> front

But yes you can use one, cars used 2 different 3.0ls, the 3.0l OHV Vulcan and the 3.0l DOHC

No reprogramming is needed, yes use your intake, upper and lower

Things to change
Oil pan gasket and timing cover gasket
Rear main seal

Changing Oil pump and water pump is up to you

1986 to 2008 3.0l Vulcan will work, later years should have lower miles

Flex Fuel 3.0l Vulcan is OK to use, as long as you use your intake and fuel injectors