Just recently got this truck from a dealer. Now I used to do a bit of mechanic work at a shop before, so although I'm no grandmaster sensei I'm not a complete idiot either. checked it out before I bought it, needed some tuning up, so I got the price down . Cool. Changed the oil (because it was way overfilled from the dealer) put some OEM-equivalent spark plugs in because, of course, the dealer had the cheapest ones possible, and cleaned the MAF, cleaned the oil out of the intake from the valve cover breather hose sucking oil up there. After all that...the truck went from having a rough idle to a smoother, but still uneven idle. Spits mad sludge from the exhaust, and a little too much water for my comfort level. Runs and drives pretty well, though. Makes it through the day without any butthole-pucker moments. Hmmm sounds like internal coolant leak, right? Weeelllllll...
-Doesn't overheat
-Cooling system holds pressure just fine
-Coolant level stays pretty darn full
-No bubbles in radiator
-No codes
-No milky oil
So what might this be? I have done the whole seafoam shebang, but a week ago, so whould that have something to do with it still? Maybe fouled O2 sensor from all the sludge being cleaned out? Its my first Ranger, and the only one I've worked on, so some insight would be greatly appreciated!

 

2000 Ranger will have the 2.5l OHC Lima engine, this was it's last year in the Ranger, it was used at the start of the Ranger model, so since 1983.
It is also called the Pinto engine because it was first used in the............you guessed it, Ford Pinto in 1971.
It came in 2.0l, 2.3l(bored out 2.0l) and your 2.5l(2.3l with longer stroke)
Very well made and reliable engine, but under powered for it's weight.
It was made in Ford's Lima, Ohio engine plant, hence the name Lima.

2001 Rangers got the 4cyl Mazda L engine, 2.3l DOHC, better power to weight ratio, Ford calls it the 2.3l Duratec engine, totally different engine than the Lima.

You have to change the timing belt on the Lima engine every 70-80k, but they are non-interference engines so broken timing belt will, of course, shut down engine but won't cause valve/piston contact/damage.

Water in the exhaust happens in all gasoline engine vehicles, which is why exhaust systems rust from the inside out, when you burn "H"ydrocarbons with "O"xygen one of the byproducts is H2O(water)
If local climate has moisture in the air then that is sucked in with the air, is turned to steam then condenses in the exhaust system which adds to the water normally in exhaust system.
Local temperature can cause water vapor in the exhaust to condense faster if it is very cold out, so instead of coming out the tail pipe as a vapor it drips out as it condenses on the cold metal near tailpipe.

If you are not losing coolant then I wouldn't be too concerned..............BUT
Cat converter normally runs fairly hot, this tends to keep exhaust hot and water in vapor form, if it is starting to fail that could show up as more water exiting the tail pipe.
Since you don't have a history on this vehicle I would see if there are any codes in computer.
OBD2 computers(1995 and up) have an O2 sensor behind the Cat converter, the data from this O2 sensor is compared to data from O2 sensor near the engine, if rear O2 sensor isn't showing Leaner(cleaner) exhaust then computer will set a code and usually turn on CEL(check engine light)


Yes, if possible pull the front O2 sensor and have a look at it, these need to be changed every 100k anyway but worth a look.
O2s tend to start failing Lean so computer will run engine Richer than it needs to be, so lowers MPG a bit which costs you money, and spark plugs won't last as long.
If the old spark plug had black tint then I would change front O2 sensor just on spec.

Rear O2 sensors tend to last the life of the vehicle since they see cleaner exhaust.


Check PCV valve system.
Remove dip stick and start engine
Put a piece of paper towel over dip stick hole and see if there is air pressure coming out of the hole.
Then raise RPM to about 2,000 and check again.

PCV(positive crankcase ventilation) system is there to maintain slight negative pressure in the crankcase/valve cover areas, PCV Valve allows engine vacuum to pull air inside crankcase/valve cover areas into intake, the breather hose is to let fresh air in.
So paper towel should cling to dip stick hole, because of the negative pressure, not be pushed away.

All piston engines have "Blow-by", when a cylinder fires some of that explosion "blows-by" the piston and rings, the hot gases vaporize some of the oil on the cylinder walls and rings as it passes by, that's where the oil vapor in the crankcase and valve cover area comes from.
Cheaper oil tends to produce more vapor, just FYI.

At idle, high vacuum, low Blow-by, the PCV valve should be almost closed, as RPMs increase, vacuum drops and blow-by increases, PCV valve which was being held closed by higher vacuum will open more to maintain negative pressure.
The standard "shake the PCV Valve and if it rattles it's good" is not very accurate, lol, while it is true that if it doesn't rattle it's bad, rattling does mean 100% good.
Good practice is to replace PCV Valve every second oil change, 6-8k miles.


Vacuum leaks plague newer vehicles.
Simple test for a vacuum leak is to get engine up to operating temp
Manual trans 2.5l should idle between 650-700, automatic 750-800 when warmed up.
Locate the IAC(idle air control) Valve.
While engine is warm and idling unplug the wires on IAC Valve.
IAC Valve will close all the way and engine RPMs should drop to 500, or engine may even stall, either is good, it means no vacuum leak.
If idle stays high then you do have a vacuum leak.

 

That is a helluva response. Well checked everything out, and I suppose it is mostly a climate thing. This truck is apparently running normal. The truck is spitting less sludge now, so I imagine the seafoam was the main culprit there. Well thanks so much, I will keep this in mind. Probably should change that timing belt though...

 

So replaced the front O2 sensor (old one was a tad clogged, and appeared to be the original anyway), and replaced the timing belt (old one was a bit stretched). I ensured that all the marks lined up again after a couple revolutions, and put it all back together exactly as it was. Now, the truck had a slight tick since I bought it, and I wrote it off as old engine tick, and it still ticks a bit after the timing belt change. Engine runs marginally smoother at above-idle rpms now, but still runs unevenly at idle. Another thing I hadn't checked before...I removed the oil filler cap with the engine running...and I'm getting smoke. Steady puffs because exhaust is getting in the head. I'm thinking it may be leaking intake valves? Is this a usual thing with these engines? Or is it maybe the valve heads are so carbon fouled that they stick open slightly? I am 100% positive about the timing--no codes, and engine has decent power. Maybe a cylinder leakdown test is in order...

 

It would be Blow-by or Exhaust valve guide seals.
leak down test dry and then wet can tell you if it is rings(blow-by) or valves that are leaking.


Check PCV valve and hose for leaks.
All piston engines have blow-by, that is normal, hot gases from cylinder firing "blows-by" the piston's rings, this vaporizes some of the oil on the piston sides and cylinder walls, this is the oil vapor you may have seen, it is technically exhaust because it comes from air/fuel burning, but usually more oily.
PCV system should create negative pressure in valve cover and crankcase, to prevent blow-by from polluting the air, that's why it was added years ago.
30 years ago there was just a vent on upper oil pan or lower block pointed down at the ground, if engine was running it would drip oil the whole time, lol, as engine got older it would drip more oil


After engine is warmed up, unplug IAC(idle air control) Valve, Idle should drop to 500rpm or engine may even stall, either is good, no vacuum leaks.
If idle stay at 700rpm or higher you have a vacuum leak.

 

you could also try the ATF fluid flush trick that old schoolers do

dump the oil and replace with ATF fluid , tranny in neutral, wheels blocked , start engine and let if idle for 30 minutes .
have a fan blowing into the radiator , after 30 mins rev the engine once every minute .

( MAKE YOU HAVE SPARE CHEAP OIL FILTERS HANDY AS WELL AS 1 GOOD 1 )

sit in the cab and keep an eye on the dash for the engine oil light to come on.
shut engine down then replace clogged filter with another good cheap 1 and repeat
restart engine

mostly likely the piston rings are jammed in the compressed position from gunked up debris
allowing blow by to occur

 

Well thanks so much for the help RonD and cheese man! I'll give it a shot.

 

did that process to my old jeep straight 6 engine . it made a hell of a difference

engine power was way up , engine generated heat was way up , i went through 6 cheap oil filters before i was finished.

now keep in mind that i kept the oil fill off the whole time , this prevented gasket seal blow outs

the sludge that came out of the engine was un-believe able

 

any updates

 

compression in 1 and 3 are way low. 89 for #1, 106 for #3, and 194 and 181 for #2 and 4 respectively. Also did the wet test on 1 and 3 and compression increased by about 20psi each. Cylinder leakdown tester should be in any day now. Did plenty of seafoaming to see if that would help. Only a bit. The way the compression gauge behaved, as well as indicators from the aforementioned posts, has me strongly suspecting some significant valve leakage. Truck only has like 118.5k

 

Could be rockers have slipped and exhaust or intake valves are closing late, so you are only getting 1/2-3/4 stroke compression.
Damaged valves tend to have lower compression than 90psi.
Although exhaust valve seats can start leaking which would still get 90psi until they burned thru.

I would just pull the valve cover and have a look at rockers and cam for unusually wear patterns, you can still do the leak down test with it off.

 

just out of curiosity, what kind / brand of engine oil were you using in that engine

these 4.0 engines are only meant for synthetic oils

i read some where that some ford 2.5 litre engines had defective valve springs installed

before i would start pumping money into a rebuild , i would replace the valve springs 1st

the only way to tell is to remove the valve cover and check spring tension

use a hammer gently !!!!!!! the valve should only move slightly when tapped

 

Update: checked valve springs, they seemed fine. Did cylinder leakage test. Cyls 1 and 3 had around 70% leakage, and 2 and 4 around 10%. Felt air escaping from the oil fill/drain holes in the head. Also stuck finger in the rearmost oil fill hole and could hear the sound of the airflow change. Used castrol gtx 5w30 btw.

 

Reads like rings, I guess pulling the head will tell the tale

 

i recommend doing the atf fluid flush before spending any major money now

it might just be jammed piston rings that need cleaning

 

most definitely will do that now that I know exactly whats wrong. i shined a light inside the spark plug hole when the piston was up and it looked all sorts of oil fouled. resembled a burnt biscuit lol. Well thanks Ron D and cheese man for the help! I'll keep you posted about that fluid flush.

 

wheels chocked
transmission in neutral
fan blowing into radiator ( if you have 1 available )
remove valve cover and carefully pour 2 bottles of atf fluid all over the valves and springs
replace valve cover
remove oil fill cap and pcv valve and set aside ( to prevent seal blow out )
pour in 5 more quarts of atf fluid ( you need to overfill the crankcase )
start engine and let it warm up to normal operating temperature
sit in the cab and keep watch on the temp gauge and dash for the oil light
rev engine many times for 2 seconds each
you will go through about 2 or 3 cheap oil filters maybe more ( purchase at least 6 cheap oil filters )
then let the engine idle for 30 minutes ( keeping watch on the dash at all times )
shut engine down then drain the used atf fluid out
refill engine with more cheap atf fluid , run engine for 5 minutes then shut down engine overnight
the over night process will allow the atf fluid to dissolve any sludge remaining in the oil pan
start engine in the morning and let it idle for 10 minutes ( once it has warmed up )
shut engine down and drain used atf fluid and remove last cheap oil filter
refill engine with good quality engine oil and quality oil filter
and test engine for compression blow by out of crank case

( this process sounds complicated but it is in fact very easy once you go through the process the 1st time )

 

Truck still has a clattery, rattling sound from the engine sometimes when I go uphill in 4th or 5th gear. Maybe spark knock or something similar? Another issue is that at idle, usaully when I have the blower motor going (regardless of climate setting), I hear a 'click' every few seconds or so and the idle dips and I see my battery voltage meter dip. I do have new coils, wires and mfg-recommended spark plugs in, as they were due anyway, so I'd once again much appreciate a little guidance here. I have done a fuel pressure test... and have a question. It gets to about 65-70, but not immediately. Slowly builds after I get the truck running. Which reminds me...I also have a pretty legit knocking noise for a bit when I start her up in the mornings. Had that issue with the old engine as well. Only thing I haven't messed with too much is the fuel system and the ECM, so I mostly suspect those, but of course I'm never too sure. Any ideas? Thanks again, y'all have been awesome

 

that clacking is more likely piston slap

the piston rings are worn out , probably just needs new piston rings and oil ring

the cylinders worn out???? i highly doubt it , there is a lot of nickel in that engine block

might need new pistons and crankshaft bearings though

those engines are cheap to rebuild and performance parts are easily obtained