1994 Ranger 4.0. Approximately 333K miles. Today I began to change the oil. It’s been about 5,000 miles since my last oil change, as the manual recommends. When I removed the drain plug, all that began coming out is extremely thick, slow, oil that drips about every 3 seconds and is ongoing now. I’ve never experienced anything like this and have driven this truck and done every oil change for 13 years.

All I have done between the last oil change and now is that I added some Lucas Oil additive maybe 2000-2500 miles ago due to what I believe is lifter and/or valve noise the truck produces these days. The noise persisted and I haven’t done anything since.

So what are anyone’s thoughts? The oil doesn’t appear to be milky looking and/or have anything noticeable in it, although I’m only letting it drip for now. I haven’t inspected it well in good light yet. Any information or tips is appreciated. Thanks

 

To add to my original post here, I've been doing plenty of reading online. Seems like I definitely have an engine sludge problem on my hands. I have experienced some problems lately with my motor starting to overheat at night when I go into work for night shift. I've battled coolant leaks and occasional overheating issues off and on for years, specifically in the hot and humid summer months like now. It seems as if things are coming to a head.

I do find it strange the oil thickened this much since my last oil change.

I've read plenty about Seafoam, engine flushes, etc tonight with differing opinions on them. Any suggestions or thoughts to squeeze as much life as possible going forward with the motor?

 

copied from https://itstillruns.com/signs-coolan...l-5907079.html

The Dreaded Milkshake
When coolant first invades the crankcase and mixes with the oil, it can leave an odd river of green, red or orange in the brown of the oil, depending on the type of coolant the vehicle uses. However, once the engine runs for any amount of time, the crankshaft and oil pump have a blender-like effect on the two fluids, turning them into what many refer to as “the dreaded milkshake." The name comes from the appearance of the well-mixed fluids, which take on the appearance of a milk chocolate shake on the surface.

Down below the thinner portion of the mixture is a thick, gooey concoction that resembles a melted milk chocolate bar. The latter mixture gums up engine passageways and is normally indicative of a ruined engine. Once the fluid has had time to mix to this visual consistency, the grit in the coolant has overcome the lubricity of the oil and scoured the bearing beyond repair.

 

Its actually 3,000 miles or 5,000 kilometers

The heavier sludgy oil will be at the bottom of the pan, but not after only 5k miles, did the oil get thinner as it drained out?

I would put in a cheaper brand 30w oil and cheaper oil filter, and a 1/2 quart of ATF(auto trans fluid) to top it up
Run that for 100-200 miles, then drain and put in some better 10w-30 and good filter, you can also use 20w-40 up to you

ATF is a high detergent oil that will clean things up a bit, but doesn't like the higher bearing temps long term, might help the lifter noise as well
But if the noise doesn't come and go its probably a lifter spring is broken, a "collapsed lifter", and you can't swap those out without pulling the heads on the 4.0l OHV, it won't hurt anything, just noisy

Not sure if Mystery oil caused that sludge, never tried it

 

 

In my manual it mentions 5,000 miles as an oil change interval for normal daily driving, which is all I’ve ever done.

I watched the oil off and on for an hour or so and it did not appear to lighten up too much. I decided to let it drip for as long as it wanted. I plan to put some cheap oil in it with a filter, run/drive for a short amount of time and see how it does, before changing the oil again with my normal oil change. I’m hoping for the best, and that some more time could be squeezed out of the motor.

One person I know recommended the kerosene trick to get the stuff out of the motor. Just keeping the plug out and pouring kerosene through while it immediately drains. At this point I think I prefer to try more of the cheap oil/quick change route before introducing anything else to the motor. I very well may include some Auto Trans Fluid as you mentioned.

Anyone with thoughts or experiences on pouring kerosene straight through with the plug out to help carry gunk out? Would it be better to go the cheap oil route first?

 

Has the oil pan drained? Were I in your shoes and if the pan has drained, I'd give it a kero rinse just to see what I could coax out.
Your description sounds like you might be filling a sink with a clogged drain. In that case don't do it.
It'd be a small exercise considering what's likely in your future. Plus, if the kero just runs into your pan and out the drain you're not really "introducing" anything to the engine.
1/3 million miles...at least one bad lifter...bearing destruction (per the milkshake description)...could be rebuild time.

 

Yes all the oil has drained out.

I’m a bit hesitant with the kerosene from the standpoint of it whisking away too much stuff from inside the engine. Maybe that’s silly on my part, but I guess I’m worried about loosening up too much stuff in the engine and it potentially causing more harm than good, even though I’m aware at this point maybe that doesn’t matter. My thinking was cheap oil and maybe some ATF as suggested above as an initial test would be a fairly safe test of where I’m at. I’m all for opinions though! From the reading Ive done there’s plenty of valid arguments on both sides here.

 

Okay. So I put in some cheap 10w-30 oil today with a new filter and half a court of ATF. The truck started and ran with its usual knocking noise. After I verified no leaks I took it for a 6-7 mile-ish drive. My knocking noise was nearly completely gone by the time I got home. The oil pressure was constant and the needle stayed in the middle of the gauge. For now I think I’ll drive the truck to work the rest of the week (pending no problems) before doing another oil change this weekend. Hopefully it will all go well.

When doing my test drive my temperature gauge needle was slightly jumping a bit. This has been an off and on problem before. I did verify before leaving my coolant levels were good. So I’m not sure there.

 

I would change the temp SENDER on the engine, its a cheap part to replace vs testing

Its on the lower intake just above thermostat housing, it has ONE WIRE
There is a SENSOR that looks just like it which has TWO WIRES so easy to tell them apart
They are next to each other on the lower intake

If you go to an auto parts store tell them you need the SENDER, 9 times out of 10 they will give you a sensor, so open it and look, ONE WIRE

Do NOT tape the sender's threads, it needs a good GROUND to work

 

Thanks for the info RonD! I’ll look into the sender for sure. I’m also thinking I should replace my thermostat. The truck was still getting a bit hot heading into work this week despite my fluid level being okay. Thoughts on the thermostat causing some of the temp gauge issues as well?

Im also draining my cheap oil as I type this. I’ll be putting in what I normally would, Motorcraft oil and filter.

What’s your opinion, should I also continue to use the ATF when I do my oil changes?

 

No on the ATF, if lifters were dirty they will be clean now, just use your favorite oil

Check heater core flow, on a 1994 that's the water pump by-pass so if flow is slow engine will overheat
Disconnect heater hoses at the firewall and use garden hose to test flow thru the core
Always reverse heater hoses at the firewall every 2 years when you change coolant, it keeps the core cleaner by back flushing as you drive

If in doubt about flow thru the core, then by pass it, pull off the heater hoses and connect them together and see if temp stays down
If so replace heater core, cheap and easy to do

After getting home from work or any drive that more than 15minutes
Try to spin the engine fan should be hard to spin, barely moves, so clutch is locked, if it spins easily then fan clutch is failing, which cause higher temp when driving slowly or stopped
Then
Remove the 2 fan shroud screws and move it back
Run your hand across the rad fins from upper rad hose down to lower rad hose
Should be HOT near upper hose and get cooler as you get closer to lower hose
If you feel colder areas in between it means the radiator tubes in that area are blocked, so not able to cool hot coolant, this would cause higher engine temp