Hiya, Pawpaw, howa you?-
Been 10-7 for while, actually logged on today to check up on the trans flush procedure, which is coming up for me...
I haven't had time to run down the issue further. I decided to try different plugs in the cyl to see if I would have any better luck with a particular brand or type than the Motorcraft, which were only lasting about 2.5-3K. So, I last installed a Bosch Fusion (platinum/ iridium) plug (P/N 4504, for the 4.0) about 6 mo/ 6K ago and it seems OK, a miss very, very infrequently, def not enough to get anywhere close to setting the MIL or be objectionable at all on driveability. I'd say about a 95% improvement, 100% being a perfectly running engine.
Till now, I really don't have any coolant attrition, but I really never did either. I've never really had to add more coolant to the Ranger than any of my other vehicles, xcept the minimal amt due to evap loss. Did not put any stop leak in either, running/ been running Prestone in it.
Plus, a benefit, even with the one Bosch plug, my gas mileage actually went up between 5-10%, and I didn't change my driving habits any, for sure!
So, admittedly I really didn't do s**t, but with many other priorities and the fact that the truck has 150K now (hoping to replace it in the next year/ year n half), I'm gonna let it ride unless something appreciably worsens.
At least I gotta say the Bosch plug seems pretty damn good! Maybe I should try a full set and see how good they really are!

 

OK, good feedabck, so you never got around to trying the #4 plug in another cyl, to see if the misfire would follow the plug, or looked at the plug under a microscope to see if you could find a micro crack in the ceramic insulator.

Did you do the oil analisis????

Interesting that the Bosch plug is doing well in that cyl.

Never used them in the Ranger 4.0L, but did run a single platinum set of Bosch in the 94 Taurus 3.8L, (that has the convinitional distributor ignition system), for 10 years & they did just fine.

Pulled them out at the 90K service call out & replaced them with Motorcraft platinum & new OEM wires.

The old Bosch were still in spec for plug gap, the threads didn't bind in the plug hole & the plugs plating was still intact, they weren't rusty, just dirty, but wiped clean.

I sure didn't have any problems with them, BUT they were the single platinum plug with one ground lug, not one of the multi-ground type, that so many have reported problems with.

On the tranny fluid pump out, here is a link to a thread on how I do it on my 5R55E tranny, some of which you may find useful.
https://www.ford-trucks.com/forums/6...-pump-out.html

Leveling the vehicle before pumping the pan out, via the disconnected tranny return line, will nearly empty the tranny pan & make it less messy on the pan drop.

Using a 52qt poly under bed storage pan will catch any remaining fluid that sloshes out on the pan drop & it's also large enough to catch the tranny drips while you clean the pan & magnet & replace the filter & that too makes it less messy.

Some thoughts for pondering, good luck on your tranny pump out.

 

Actually I did all those things- on the last plug change, I put the plug in another cyl, #5 I think. The plug did misfire, the MIL did set for #5 when I put the jacked up #4 plug in there. I did find a cracked insulator on it too when I inspected it. But that was the first that was cracked out of 3 or 4.
I did do the oil analysis, Blackstone found a little antifreeze, .19%. No water. Sodium and Boron were higher than avg. sodium 94, avg. is 10, boron 154, avg. is 69. All other elements below avg., some way below. But Sodium and Boron could also be found in the chemical makup of the engine oil too. Blackstone said since I change my oil at 3-3.5K intervals they felt I could live with the antifreeze.
The Fusion is the 4 lug style. I have also seen problems with the multi lugs, but in this app it seems excellent. Go figure...
I am going to review the tranny/ TC pumpout. I also have the 5R55E. I did read it a while back but I wanted to revisit it. The filter should be good, changed it about 40K ago. Was going to let it go this time, last time it was pretty damn clean, even when I tore it apart. Stupid that Ford didn't put a plug on that tranny's TC like they did on my many other Fords Iv'e have over the years.
A pan drain plug would also have been nice, my SD's have them. Much cleaner! If I was going to keep the Ranger for a long time more, I'd fab up a drain plug on the pan and also install a TC plug...maybe that's a topic...how to install TC and pan drain plugs on a Ranger...chew on THAT!
And, maybe I will install them anyways...wouldn't be hard...anybody thought of doing that?
As always thanks for the interest and tips. I'll try to drop by and say Hi more, and stick around a little.

 

OK, more good feedback, so the plugs insulators Were cracking!!!!

But so far no one has found a reason & so far your the only one to have found that a plug brand change, thats made a positive difference & thats interesting too!!!!

I know we've speculated on cracked heads causing some kind of thermal stress on the plugs, lean air/fuel ratio in the affected cylinder, coolant circulation problems causing a cyl to maybe run hot, carbon deposits that cause detonation in a particular cyl & cause it to run hotter & damage the plug, plug design problems, over torquing the plugs, ect, ect, but so far we've not been able to nail down any scenario that seems to consistantly fit a pattern.

Don't know yet why so many folks with the 4.0L have plug crackng problems, so we appreciate all the feedback.

Your findings may not provide a definitive answer for everyone just yet, but it works for you & it provides more pieces to fit into the puzzle, so sooner or later I'll bet the picture will become more clear.

On draining the tranny fluid, there are drain valves available that can be installed into the tranny pan, but I don't know about doing it to the torque converter. Adding weight of a drain plug to the outer diameter of the torque converter would likely unbalance it & that might cause mischief.

I really find it's much easier to just disconnect the tranny return line at the cooler & let the tranny pump empty the system!!!!

If we're going to install a new tranny filter, we have to drop the pan anyway, to do that & if we'll first let the tranny pump do it's thing, with the vehicle level, it'll get most of the fluid out of the pan before the drop, so it isn't so messy.

Let us know how the tranny pumpout goes.

 

new to the site. i've been reading these threads fro a few hours now and you guys seem to be the people to talk to about my issue. i also have a 98' xlt 4x4 4.0L, and my problem seems to follow alot of guidlines as everyone elses. Rough cold start, but goes away after a minute, the only difference in mine is that my misfire also happens under load and open loop conditons ie.. 3,000-3,500 Rpms, and usually under wide open throttle. now the problem can become intermittent, and in fact dissapear after running it for a bit. The issue im getting which i wouldn't be surprised if they were un related is a lean condition not enough to set a DTC but still sitting anywhere from 12 to 17%+ on long term fuel trims. I've tried almost everything. Ignition wise everything is new ( plugs,wires,coil ) i even threw a new MAF at it for **** and giggles but no change in the numbers. I've smoked the motor thinking the intake manifold gaskets as they are ntorious on these things and nothing showed. I also gone as far as to disconnect the Cam Postion sensor (knowing that both the sensor and the shaft are notorious on 3.0L, but nothing) and then run the vehicle hoping that reading the Crank sensor alone would remove the misfire. Nothing. I have rulled out EGR, Crank PS, Cam PS, compression, and all ignition components. I have also ran mode 6 in my scanner which tells me that nothing but Cyl 4 is missing although not enough to set the DTC it definetely is bucking and missing under load. I did have to add a little coolant this summer but nothing radical, I have also not noticed any in the oil or in the cylinder during diagnosis. I have not ran cylinder leak down yet but in my experience I just dont see the emminet signs of a bad headgasket. So know that i have bored you with all that i'll get to my question. I noticed in one of your threads you said that the lower intake manifold mounting bolt might work their way loose. Did you have this misfire under load issue with you vehicle as well? Also you mentioned something about sending out used oil for a lab to check for coolant, what lab, how much did it cost, and what was the turn around time?

 

Welcome to FTE swift722.

Not sure who your posing the questions to, but Rockledge was the one that had the intake manafold leaks.

It looks like your problem is likely to be rather different than B A dawg's, who's problem seems to be spark plug related, so you should open a new thread just for your problem/s, so you'll get more replies specifically for your situation & it'll be easier to track your trouble shooting progress & success.

Just click on "Ranger & B-Series" in the header atop this page, to go to this forums thread listing page & when it opens, click on "Start New Thread, then title it & maybe cut & paste your above post into your new thread, or retype your questions there & we'll all take our best shot at helping you come up with a diagnosis.

 

thanks paw paw i posted a new thread. i originaly sent the message to rockledge then just cut and pasted it to this thread. the reason i was asking him was two fold to find out info on labratory oil test and the fact that he mentioned something about the manifold bolts might have worked thier way loose. i was just curious although i have the majority of the same symptoms of this thread i differ in the fact that mine also misses at open loop.