Ford Explorer / Ranger / Mustang 4.0L SOHC V6 Teardown! Is This Why They're Called "Exploders" ? 

I'm just here for the dipstick battle....

My dad had the OHV 4.0 in his 1995 Ranger and when he died the truck had 633,000 miles on it and it still ran great.

That 4.0 is insanely reliable. Don't let him scare you by talking bad about the timing chain. Just do your oil changes every 5k and give it an italian tuneup every once and a while and you're golden.

Mine has 253000+, great engine, never failed me. Sorry you fail to convince me.

On the front drivers side timing chain guide, you unclip it so it splits into 2 halves, then you can remove it without pulling the head 👍

im a used car dealer and I have been in the business for over 25 years. The 3rd and 4th generation ford explorers have been my best sellers for a super long time and I know them super well. The 4.0L soho motor in 80% of them that I've purchased. out of the hundreds of them that I've owned only one of them needed new chains and guides and STILL ran perfect. this motor is nowhere near bad at all. just keep up on oil changes, they like thicker oil and clean oil.

The most impressive thing about these engines is they are almost impossible to stall. A buddy had one in a mustang when he was learning to drive stick, and he could regularly get going with the rpm's dropping below 250.

Bought a 1998 explorer with the 4.0 SOHC brand new in 1997. 290,000 miles and never had an issue with the engine or even the transmission. Most reliable vehicle I’ve ever owned.

A relative of mine has a 2003 Explorer with this engine, and his "mileage varies" ("YMMV") greatly from that expressed in your opinions. The original engine has 225,000 miles on it, uses no oil, makes no noises and has very good oil pressure. He drives it every weekday at least 100 miles on his commute. He changes his oil every couple of months. The only repair he has ever had to do was the thermostat housing. Maintenance makes a difference.

Had to do the timing chains on my wifes Explorer about a year ago... biggest thing that had me questioning the universe was: non-keyed cam gears (held in time purely by bolt torque), that required a toolset to time... That engine better hold up after all the hours I put into that. Notes for others that are looking to perform the timing chain repairs: 1. No, you cannot do the rear timing chain cassette without removing the engine... people are full of crap if they say you can. you have to remove that little torx bolt towards the bottom of the cassette to remove the guide, and its obstructed by the trans bellhousing, as stated in the video.... (yes, it leaks from the rubber seal if you try to reuse it, don't ask how I know...) 2. as I've previously stated, you need that timing toolset to reset timing on the cams... it's not worth saving the $40-60 if you end up having to replace the engine. 3. get a replacement rear main seal, its worth it. 4. If your 4.0 has the balance shaft (when looking at the front of the engine, its to the lower left of the crank), be very careful torquing the 4 E-Torx bolts that hold the balance shaft assembly in, I snapped 2 of them off.... added 2 weeks to my repair time waiting on parts. 5. yes, you can get the front cassette chain guide out and in, without removing the cam or head. just remove the jackshaft gear, and pull the old chain guide out through the bottom, by pulling it hard towards the front of the jackshaft. if you have patience, you can very carefully maneuver the new one in, though its a pain... if you're impatient like myself, just remove the c-clip on the hinge of the guide, and replace it when you get it in place. 6. it's expensive, but CHECK WHICH BOLTS ARE TTY!!! There are ALOT of them when doing this job... I have Ford part numbers, if anyone needs em, just reply to this comment. {Edit: when I says it's impossible to do the rear cassette without removing the engine, I was referring to separating it from the transmission, and yanking the motor out. Sure, you probably could pull the tranny out, but I would strongly advise just pulling the motor... So much easier to torque things to spec with the engine out, ESPECIALLY when it comes time to time the cams}

I have had 2 4.0L fords and there was absolutely no problem. 1 in a Ranger and 1 in an Explorer. Both had plenty of power and never left me stranded.

I wanted a Toyota 4Runner but couldn't find one in time that was good condition, so I settled on a 1996 Explorer 4.0 OHV V6 around 4 years ago. It just passed 240k miles. The engine being so reliable has definitely made me less apprehensive about throwing money into other parts of the car to keep it rolling. I don't want to get rid of it. Even if I had to rebuild the engine next week, I am confident it would outlive me.

This is what one ends up with if one converts a simple ohv design to overhead camshafts without re-designing the whole timing system. That shaft in the valley is where the cam used to be in the old "Cologne" V6. Thanks again for all your great videos, all the best!

The reason the timing components are backwards like that is because this engine was developed from a pushrod block (The Ford Cologne V6). The shaft that goes through the center of the engine to drive the rear timing chain was originally where the cam went on the pushrod version of the engine. If you look at the top of the block on either side of the valley you can see the cutouts where the pushrods would have went into the OHV heads.

The 4.0 is actually a very durable motor if it’s taken care of. A lot of Ranger guys love it, especially the older OHV version. Admittedly the OHC version has a disaster of a timing chain design.

This is actually a reliable engine. I have 212k miles on my mustang, full synthetic every 5k miles. Never had any problems except changing the plastic thermostat. Really simple engine and can run forever if you just change the oil on time

I had an 05 mustang with this motor, had 190k miles when I sold it. Ran flawlessly, but I always kept up on the maintenance and oil changes. It was a fun car with the manual trans and got decent mileage.

Just sold a 1999 Explorer 4 liter I bought new. It had 186,000 miles and was running well for its age. Oil was changed religiously every 3000 miles. I had heard the horror stories about timing chain death rattle but my experience was good. I think most issues are probably due to infrequent oil changes.

The early warning signs of timing chain issues on the 4.0L are almost always ignored. Yes, the timing system is very flawed in design, but there are steps that you can take to prolong the life of the timing system and engine. The first part in this timing system that gives is the chain tensioners, which leads to broken guides and eventual failure. As the poorly designed tensioners age, they become weaker (as we saw in the video) and cannot hold down the guides to keep adequate pressure on the chains. This is especially true on cold starts because oil does not reach the tensioners immediately, which allows the timing chain to slack and bang off the plastic guides, creating the characteristic 4.0L "startup rattle". After many cycles of this, the guides break and the rattle becomes constant while running/under acceleration until enough of the guide material is broken and the timing jumps--leading to an often catastrophic failure as these are interference engines. This can be prevented, or at least prolonged, by replacing the chain tensioners every 50-70,000 miles with new OEM units (Ford still makes them and they are cheap); they're outside the engine as seen in the video and easy enough to replace that a DIY'er can do it. Another issue that isn't spoken about nearly enough is the use of improper oil filters on these engines. These motors NEED oil filters with anti-drainback valves (OEM Motorcraft FL820S or equivalent) to help against oil starvation on startup to the chain tensioners--this alone will help prolong the lifespan of the timing system in these motors; the same ironically applies to the 4.6L SOHC V8 which can suffer from similar timing issues. Both the tensioners and oil filter are cheap insurance that almost anyone with minimal mechanical knowledge can do in their driveway. It's not uncommon to see these reach very high mileage, even while rattling around on broken chain guides--they're actually quite durable motors. Notably, the original nylon chain guides on this engine from 97-01/02 were deemed to be too weak by Ford, and the timing components were revised. Later models do fare better, however, all of these engines will eventually run into timing issues unfortunately as the design is just inherently flawed as a whole--the trick, again, is to catch it in time. The upside is that they made literally MILLIONS of these engines and parts are easily obtainable. I've owned and continue to work on a number of cars with this engine. By far the worst 4.0L timing failure I've personally seen so far was an 01 Ranger on original chains blow a hole straight through the driver side valve cover at around 260k.

I've owned two. One one currently. 1998 explorer sport. I love the 4.0 v6. Keep up with oil changes and don't drive them low on oil. And you will never have a timing chain issue. It definitely doesn't lack in power in the explorer either. Mine dips.

This is an OHC engine design based on a older pushrod engine. That's why the timing chain design is so odd. The jackshaft is where the camshaft was in the pushrod version.

I just happened to watch a video from another channel. The Foam was intended to keep critters and debris out of the valley. They unintentionally made the foam absorbent so it allowed water to build up and rust anything that is in the valley. They apparently did this with multiple different engine designs

I owned an Exploder with this engine. If I recall correctly it had 220K miles on it when I got rid of the vehicle. Not only didn't it burn oil. . . it didn't even leak any oil. Yes it didn't make a lot of power, but it was dead reliable for me.

rebuilt my 2004 4.0 because of the timing chains , the small chain on the balancer is on all wheel drives, that one was the main one that was loose and rubbing on the cradle . if you ever do one , make sure you don't buy the cheap timing chain kits ,I went with Cloyes complete kit for 330 i believe ,also bought a special tool to align over head cams , for 200 and sold it after for 150 . all in 1300 for refreshing everything including the heads. Runs like champ

Our 2005 Mustang with 182k is still going strong. No noise, now I’ve replaced both the tensioners and stayed on top of the maintenance. Engine is great around town but not great when cruising and you want to pass someone. Knock on wood it’s been a good engine for us. Not my wife’s daily anymore so only sees 5-6k a year.

I have an explorer with that engine. I bought it new in 2002. It was a great little engine when new, and it towed an 18 foot boat for almost every summer. At about 130,000 in 2013 it’s started the death rattle. I’m like, oh well, it’s been a good truck, once the engine blows up I’ll get a truck or something… wouldn’t you know? 10 years later and about 70,000 miles more the darn thing is still running. It was my first car, and it does hold sentimental value. But in the grand scheme of things, it’s just a Cheap XLS AD car I bought from magic ford 21 years ago.

I had an 03 Ranger with the 4L 2WD in it and I loved it. Wife needed another vehicle that “wasn’t” a truck so I had to watch it go.

The Ranger with that engine and the manual transmission was so much fun. It didn't do anything perfectly, but it did just about everything well enough. It's one of those vehicles that you grow fond of.

I'm in the 'like' group, from an engineering standpoint. That engine started out as a 1200cc OHV V4 with a balance shaft in 1962. And after 49 years went through the removal of the balance shaft, had two cylinders added, went from a cam gear to a cam chain setup, was there are the beginning of EFI, went through several more displacements and was then retrofitted for single AND DUAL overhead cams (cosworth version). The fact that these engines still held up as well as they did after basically being a genetic freak, goes to show how good the original design was. And, truth be told, the lifetime and failure rate of the factory timing chains is about equal to many other engines, it's simply the labor costs, difficulty and complexity that puts people off. Having one chain up front and one out back, for one, allows one cylinder head casting to be used on both sides, and for two, allows the vesitgal camshaft tunnel to be taken up by a 'jackshaft' as people call it.

The chains were what sent my parents 98 explorer to the junkyard. It started to clatter something awful and to have it fixed wouldn’t have made financial sense, at the time it had just under 200,000 miles and the rockers were ate up with rust.

I had a 4.0 SOHC in my 2004 Explorer Sport Trac bought new. Put 200k miles on it and pulled my boat a lot. It was a great running engine. Changed the plugs at 100k miles. Only problem - had to re-lace fuel pressure sensor that cost $20 bucks. This is a great engine.

Those for 4.0 engines have hydraulic chain guid tensioners. There is the spring inside of them, but they don't get stiff until the engine builds oil pressure.

FINALLY, a teardown of an engine I own. I have a 2006 Ford Explorer with this engine. Just ticked over 190k miles. I had to replace the tranny about a year ago at 176k miles and a few suspension/wheel pieces but the engine just keeps running. The only major engine repair was a harmonic balancer in 2017.

My father had a Sport trac with 300k that ran perfectly fine. Last year he traded it in for a new Maverick. Other than replacing the coil pack and a fuel pump nothing went wrong with that engine. I have heard these engines had timing issues but we lucked out and didn't have any problems.

I drove a 2004 explorer with this engine for several years and in my opinion this engine was the best thing about that vehicle. The engine was super quiet and on idle sometimes i couldn't tell if the engine was running or not. Put about 280k on the engine, but ultimately the poor transmission eventually sent it to the junker.

Considering how difficult it is to service the timing chain, I can understand the "only thing wrong is some timing chain noise" . Can also understand why it gets let go until it fails. Seeing the difficulty involved in fixing the chain 'noise' problem is likely pretty pricey, hence the owners reluctance to fix it.

I've owned two of these engines, a '97 and '02 Explorer. I have to admit that I had no idea the timing system was this complex, but my experience saw both engines be incredibly reliable. Ford issues a recall on the timing chain tensioners on the '97 somewhere around 2000. That took care of the rattle. The '02 never had a rattle and for the 135k that I owned it, not one issue with the engine or any other part on the drivetrain. Of course mine got regular oil changes, etc but I know several other with long lived 4.0 SOHCs. Also had a fleet of 4.0 rangers at work. Same story, no engine problems whatsoever and most of those went well beyond 180k when other problems led to turning them over. Just my two cents worth, but I think these engines get a bit of a bad rap...

I had a 2005 Explorer back in the day that had over 170k on it before I sold it. My grandparents bought it new and sold it to me with around 80k miles. No chain rattle, never leaked, never didn’t start

Between my wife & I we have owned 5 of the 4.0-liter engines they all have been good to us. I still have a 2001 Ranger with 220,000 miles on it, it's the smoothest engine I've ever seen or heard. I use it around the farm & as a grocery, gas, beer, deer getter now a days. We had a rear end go out on one ranger 'hers', & some minor 4wd problems related to the electric motor that engages 4wd. Some of our engines were made in Germany, very smooth engines , some in Canada.

Hands down my favorite RU-vid subscription. I bought a 2008 2wd with just 48k on its ticker a few years ago. It was a guy’s wife’s truck and he made damn sure it would never leave her stranded: oil changes every 3k, always detailed, garaged. All service receipts. I continued caring for the truck with this obsessive adherence to maintenance, changing ALL the fluids and using synthetic everything; new plugs, wires, filters. It was the best deal I ever scored. I learned about the timing cassette issue later and dreaded about it but not before I put 35,000 more miles on it in 16 months. I had to sell the truck to raise money for my kid’s tuition. Sold it to my brother for his high school son. He got T/boned in it and it was totaled. But he walked away unscathed. Truck did its job with its canopy of airbags and stout frame design. I wish I didn’t have to sell it. Eric, can you tear down a Mercedes M112 V6? If you can find one. They are amazing engines that if properly maintained have the life of a good diesel.

Eric, I just got done working a 22 hour shift...and after THAT, there is nothing better than plopping down on the couch and having a new I Do Cars episode pop up on my screen...

About 90% of those engines if the owner would simply replace the $100 tensioner when the old one fails, generally around 160-180k miles, they would run another 100k miles flawless. Have done dozens and many ran another 100k+ before the second tensioner failure, some i did a full timing gear replacement on and still running today. 6 have over 350k miles still driven daily

Hello Sir, I have a 2002 ford explorer sport trac, this why I watched your video of the 4 ltr engine . Normally I don't subscribe to these channels. The people don't make a lot of sense, and they tend to really ramble on or are stating thing that are incorrect. You were talking and it really wasn't rambling. really enjoyed your video, I plan on seeing more of them.

The vehicle that this engine was in was someone's pride and joy at one time:"you want to go for a ride in my new Ford exploder" Jim said beaming with pride. lol

As an independent tech who's had to work on these, I hate the 4.0 sohc. And actually had to dust off my timing tools for a 4.0 late last year, after I thought they were all dead and gone.

Liked this one. Had one of those in my '08 Mustang. Treated me well,but I traded the car at 84,000 miles, From day 1 I had the chain noise, but it never caused me a problem. Mine had Mobil-1 from day 1, and it had oil changes every 5,000 miles.

My grandpa had a ranger with el Manuel and it was a glorious engine with us. The induction noise was awesome. Changed oil every 3k. Hauled more wood than most half ton minivans even dream of.

Stick with the OHV 4.0. It's so much easier to work on. 440,000 miles on mine and it's still running. Keep up the great content. 👍

Our 2006 Explorer with one has 340,000+ miles and still counting.

Had nothing but great luck with those. Smooth, no noise

Thank you for this. I have one that I repaired the timing chain system on at 200k. It has 270k on it now

Thanks for the video. I grew up working on vehicles, and worked professionally for 18 years on them. I stopped making a living doing it in 1997, just before the time of the 4.0L timing chain failures. I always heard what a dumb idea they were and what one would have to go through to make the timing component repairs. After watching your video I am glad I avoided it. Thanks again for taking me down memory lane. I truly enjoyed you video. Wishing you all the success in the future. P.S. there sure seemed to be a lot of shellacking in the bottom of that oil pan.

I had a 2001 Ranger with this engine and I loved it! With a tune, 4.56 gears and 33’s it was fairly quick. I ragged on that truck for nearly 20 years! Engine never gave me a lick of trouble. I’d buy another one.

I have a 2010 explorer with 239k on it and it still runs great. I did all the scheduled maintenance and changed the oil every 5k miles with Valvoline Synthetic blend oil and a Motorcraft oil filter. Put in a Jasper remanufactured transmission at 220k. My son drives this vehicle to school and work daily.

Well my fellow mechanic in our fleet these engines have delivered the miles 2006 Explorer 202,000 miles, 2006 Mountaineer 181,000 miles, 2008 Explorer 194,000 miles, 2010 Mountaineer 159,000 miles, 2010 Mountaineer 162,000 miles, they're still in the family and still in daily driver service. They get regular Oil and filter changes plus regular Trans flushes and Coolant flushes. Some of these vehicles replaced 90's models with the 4.0 push rod engine with high mileage.

I had one of the ohv 4.0 in a 99 ranger, then 2 of the sohc 4.0s in 2 newer rangers. Never had any engine trouble besides the serpentine tensioner pulley bearing squealing after 30k miles… I replaced a lot of those. And a bunch of clutches… but that’s it.

Did the timing on mine few years ago! Still running strong ... knock on wood (nervous sweat)

I would love to see a tear down of a Buick 3800. Series 3 preferably but I’m not particular. That motor is really reliable, from what I’ve heard, so I understand if it’s hard to find

You are on a roll in my life first the Dodge V-10 and now the infamous 4.0 ford. Yep I had a 2011 little ranger 4x4 with this engine and the knocking started. It was well maintained. I took it to ford and asked about it and they told me point blank. We can replace with a new engine cheaper than repairing that one. So I am still running it after four years. I make sure the oil pressure is up and the engine is warm before moving. That helps a lot with the knock. However, looking to put a 5.0 in it. Lots of these swaps have happened. Thanks again for the awesome insight into this engine.

Nice work, I always enjoy watching your videos!!!!

Never had an OHC 4.0, but my 91 Explorer had the OHV - never had an engine issue, and I actually really enjoyed the truck. I sold it to a friend - who actually still owes me almost 20 years later - and the 5-speed cracked in half and left him on the side of the highway in SF. Call it even.

I bought a 99 explorer with this engine for 500$, the timing chains rattled from 292000 miles to 312000 miles when I sold it, for 500$. Eddie Bauer, everything worked, also crashed it and got insurance money. Amazing truck

I inherited a 1999 Ranger XLT 4x4 with the 4.0l V6. It’s all original with over 270,000 miles. My brother changed the oil every 3,000 miles, he kept a log book with every fill up, oil change, tire purchase etc. The truck still gets over 15 mpg around town. Everything works, AC, radio, cassette, CD, power windows. T he only change I had to make was the vacuum front hubs to a manual locking hubs. It may be an anomaly but I prefer to think it was meticulous maintenance.

Love the channel Eric! Apparently the balance shaft was used only vehicles with 4x4 drive. The little info I’ve seen speculates it reduces vibration overall with the transfer case on the 4x4 drive train.

Friends have a 2005 with over 310,000 miles on it. Fluid changes early and often. All original. Probably built mid-week.

There IS a way to get the front timing cassette out without removing the head. I saw it on Ford Tech Makuloco, you need to tap on the hinge in the cassette from below until it clears the limited space between the head and the block. Of course, a timing job on these is an engine out job, so you havo lots of space....the new cassette comes with a hinge that can be disassembled for easy installation.

I know people with ford sport track with the 4.0 and still running till this day with out problem but not going to lie thanks to this channel I now know how these engines are built

I’ve learned quite a few things about engines watching this channel but, mainly, I’ve learned some excellent interpersonal etiquette… always start at the front.

I've got an '06 Mustang and it's been good so far, 156,000 miles. I have to agree that timing system sucks. If it goes bad, I'm more likely to find a wrecked 4.6 and just swap the whole drivetrain than to repair the 4.0.

My 05 Ranger had 527000km on it. The timing chain had been done. Regular maintenance is key, like with everything. The transmission was the weak part of that truck. The engine did eventually die but that's because it got hydolocked. And it actually drove home that day, and for an additional 6 months. It's getting 5.0L V8 swapped currently.

I loved the power and smoothness of this engine in my97 explorer, but mine rattled too, gave it to my friend at 250,000 miles, still ran great, I got a mint wj now

I actually rebuilt one of these POS about 5 years ago and it is still running .. used all high quality aftermarket parts , higher compression , flat tops ,milled heads etc etc

No need to take off the head. I did the chains in my 2009 Explorer and if I remember correctly you have to remove a clip on the pivot on that chain guide and separate the two halves and remove them one at a time. Zero timing marks on anything but I have the tool kit needed.

I like these engines because I'm a parts manager at a Ford dealer :)

Good video Randy. I hope all is well with you and yours.

I had an 03 Ranger Edge with one of these in it. It had 280k on it. The truck died because the transfer case got stuck in 4x4L and it basically wouldn’t move after a while. That, and the cab was so rusted, I had to ratchet strap both the doors shut. The engine still ran perfectly though 😄

The balance shaft was installed on 4wd versions. There was a harmonic that would occur.

My 2001 Ranger 4.0 4X4 has 276,XXX miles and is running like a top. Synthetic oil changes every 5000 miles or 5 months. Still runs perfect!! Gonna drive it until it dies cause it’s been paid off for 3 years now lmao.

I have a 2011 Ranger 4x4 with the 4L. It was purchased new by me in 2010. So far I have 310,000 kilometres (almost 200,000 miles for my southern cousins) on it with no problems at all. Burns no oil, and makes no alarming noises hot or cold (and Canada can get very cold). The engine has been serviced every 10,000 kilometres since new, including oil and filter change. It hasn't failed me yet, runs like a top. Not the best truck I ever owned (that would be the original Nissan Hardbody in '86), but so far a great truck. I think most of the problems with this engine stem from indifferent or even total lack of maintenance. It's my understanding that the 4x4s have that balance shaft.

I helped my grandpa do a timing job on my grandma's 99 explorer at 100k. With the car on blocks we dropped the transmission and did the whole job without removing the engine. Took us 3 days to do it in a driveway.

Had a 01 Explorer from 2013-2020, I somehow did not have any timing chain issues and I got rid of it at 178,000 miles. The last week I did have it though, you would hear the chains grind for a minute, then it went away. That was my queue to sell it lol. Besides having to always replace the thermostat housing every other year, it was a solid vehicle. If I had the choice I'd definitely go with a 5.0

I love your enthusiasm, man. I never miss an upload. It's one of my favorite favorite channels on RU-vid. Can't wait to see more engine teardowns.

This is my favorite engine autopsy channel!

My family has had several of these engines and they're all rock solid. I cannot say I share the heat on these.

I had a 2002 ford explorer 4.0 that I sold last year with 290,000 miles ( mostly highway) put two transmissions in it but engine ran good, I actually really miss it, I like how it rode with the independent suspension and lots of room to get giggy w it in the backseat

I was hoping I'd see one of these torn down. I have 230k on my mustang with this engine and it's been great, even survived a mega overheat after the thermostat housing failed. It's my daily and sees 4.5k+ rpm very often. There's no complaints from it's loyal service here.

This guys great. Wow. So glad I came on this channel

I had an 03 ranger with a 4.0 and a 5spd. I loved that truck and I luckily never had any issues with it.

That engine has some sentimental value to me since my first vehicle I learned to work on in my parents old 2004 ford explorer though the transmission was more of an issue than the engine. Btw the middle shaft for the timing system is called a jack-shaft.

I liked the torque this had at the bottom end and the sound was not unpleasant. The OHV version of the 4L makes more sense to own.

I worked at Ford Esseex engine. The only engines with a balance shaft were for Front wheel drives. The reason is v6 engines naturally vibrate front to back. This is not a problem for RWD. FWD the engine sits sideways and the balance shift is so the car don't rock while idling.

Found your video's about two weeks ago, and for fun, I thought I would watch an engine teardown. So I kept seeing more teardowns, I have watched about five of them, and enjoy seeing what is internal on various engines. I like your methods when tearing down an engine, along with your commentary makes it entertaining! You are a lot smarter than all those yaks out in Warshington, why not run for congress? Haha. Keep of the video's, enjoyable and educating!

Good evening Eric. Looking forward to this tear down.

Anytime there's a safety tote sighting, it's a great video. I remember when these engines first came out. Ford recalled these for tensioner issues and the oil pump drive. That drive on early versions would rub the side of the block and cause sparkles, enough to require replacement of some engines. I did a couple of them in Explorers back in the day.

I had an 04 Explorer with this engine. It died with less than 100k. God bless those that got reliable performance from theirs.

I had the 4.0 in my 04 explorer and it was a awesome suv !!! It was in my family for about 10 years ...

I love the dipstick battles, it's fun to watch... Love the channel, and I never miss a tear down...

I sold my explorer with 270k on my 4.0 and it never had any issues. Only thing I ever replaced besides spark plugs was an ignition coil. On time oil changes make a difference.

What a satisfying pop to those sparkplugs

I've got one of these in a 2005 explorer. It has 185,000 miles and still runs strong and quiet. Not going to repair anything if it breaks, just throw in a Jasper reman...The timing chain repair is more than the reman.