4.0 SOHC - a real PITA for maintenance

[410Fortune]

ah the first time I remember that

You should know this engine (and all engines for that matter) is a living breathing thing, meaning engine design and performance evolves over time, this 2000 model year 4.0 SOHC engine started life as a 2.6L V6 back in 1969 under the hood of a Capri. The gas crunch was on, Toyota and Nissan mini trucks were making their way to America, Ford needed something. They are in cahoots with Mazda developing the mini truck "the courier" and in 1983 the ranger was "born" The engine went through many many changes over the years and eventually the cams went over the head and we got the HUGE 4.0 SOHC. Under stress from the EPA to make more MPG but give the customers the v8 power they crave these things take TIME to develop and not everything is a CHOICE some designed gets to make. You have to weigh your options. YOu had better believe for every engineer behind a computer saying "I can make it fit" Ford has a R&D department of dealership mechanics that test things out in the real world, under hood environment before we ever see anything on the showroom floor.

The astronomical cost of designing a new engine (or trans) from the ground up is HUGE, so you HAVE to evolve the designs you have. For us the Cologne V8 started out in the 83 Ranger as a carbed anemic 2.8L v6, then early EFI was added and it became the 2.9. Finally bored and stroked the 2.9 lost its distributor and became the 4.0 pushrod.....later the pushrods were ditched, a new overhead cam head was designed, chains were added, and now the same old 60 degree v6 block is making 235 horsies and v8 torque.....the SOHC V6 is a engine bay full of compromise, same as ANY other make or model out there.....
Now I hear you! MY wifes FJ cruiser is also a 60 degree DOHC v6 and makes v8 power gets v6 MPG.....awesome engine from Toyota.... and under the hood of the FJ NOT CROWDED, in fact its like an old muscle car, you could almost sit on the inner fender while you change plugs... but the FJ was designed AROUND this idea.......our Gen II explorer WAS NOT, it was an EVOLUTION of existing platforms......

So the first year of the SOHC was 97, what a disaster fro Ford....yikes. Recall all of them 97 and 98 model years...ouch.
But by 2000 they had nailed it, the SOHC was working great,powering all sorts of Fords and crammed into their engine bays. It is us, the customers and the DIY wrench monkeys, we come up with the new ways to do stuff, just like Fords own R&D guys, somebody will discover you can get to the spark plug #3 from behind the pass tire with a bunch of extensions and a wobbly........spread the word! Next thing you know instead of a 3 day challenge full of cussing, armed with new knowledge you can tackle this job and your mind will open up and be like "Ah I see why they did it this way"

I am fortunate, I have dismantled and crushed more explores in a Summer then most families will own in a lifetime, so I get to see the engineering, the mid year changes, the plumbing hoses get shorter and more direct, the wires get shorter and better routed (saving copper), the intake get laid out better and more cleanly giving mechanics more access...it is all one big COMPROMISE under your hood. It is how we handle these challenges that make a good mechanic. PATIENCE is the #1 skill a good mechanic must have.
I like to rant just like the next guy, but when it comes to these engines and transmissions, there is no easy one size fits all solution that makes everyone happy...the designer, the mechanic, the government, the salesman and the customer........compromise.

Ford Cologne V6 engine - Wikipedia

en.wikipedia.org

Don't even get me started on the C3/C4/C5, A4LD, 4r44e, 5r55e, 5r55w transmissions.................... whew you want to talk about compromise and evolution in the drivetrain world? look into what they go through to produce a good modern automatic transmission!! BILLIONS invested just to keep the same ol auto trans going for a few more models because the R&D to produce a new model would put most auto makers right out of busniness

 

[BTR]

For us the Cologne V8 started out in the 83 Ranger as a carbed anemic 2.8L v6, then early EFI was added and it became the 2.9.

I think you meant to say "... Cologne V6..." Yes? No?

 

[MrQ]

Ahh, another "I hate the SOHC, Ford was stupid" thread.

You see these quite often when a new SOHC owner decides to do their own maintenance. Trust me, their are dumber designs and worse spark plug replacements than this engine. You just now happen to own one that challenges your skills more than you are used to, so you call it "stupidly designed."

Remember two things about ALL vehicle design: 1) Everything is made to increase efficiency during assembly; maintenance access is very low on their list for anything that doesn't need to be changed regularly (air filter, oil filter). 2) Everything is built for profit, the conveniences are mostly designed for those who USE the vehicle, not those who maintain it.

Whether these designs are good or bad is decided by how many end users didn't need to use their factory warranty.

 

[410Fortune]

yes I meant v6! good catch No cologne 60 degree v8 exists as far as I know

At least its not a 6.0 superduty.....where the cab has to come off to do just about anything to the 6.0 powerstroke. Imagine that REMOVING THE WHOLE CAB for engine access..........
So it could ALWAYS be worse

 

[koda2000]

yes I meant v6! good catch No cologne 60 degree v8 exists as far as I know

At least its not a 6.0 superduty.....where the cab has to come off to do just about anything to the 6.0 powerstroke. Imagine that REMOVING THE WHOLE CAB for engine access..........
So it could ALWAYS be worse

LOL - I just watched a YouTube video on replacing the PCV valve on a mid 2000's Bentley.
- 6 hours labor (dealer hourly rate $245 an hour) and $1500 for the PCV valve. I guess if you can afford to drive a Bentley that doesn't seem like too much money and I doubt you're a DIY'er.

 

[410Fortune]

closes ford shop and opens Bentley service shop....holy smokes, $1500 PCV valve! HAHAHAHAHAHAHAHAHAHA
Is it magic? Or simply a check ball vent valve?....probably uses a chevy part repackaged

 

[C420sailor]

Oh god don’t start me on the 6.0 diesel...what a heap...

 

[koda2000]

closes ford shop and opens Bentley service shop....holy smokes, $1500 PCV valve! HAHAHAHAHAHAHAHAHAHA
Is it magic? Or simply a check ball vent valve?....probably uses a chevy part repackaged

Must be magic. It's inside a rather large black box, which is buried under the twin turbos and turbo related plumbing. It's actually an Audi part (which is much less expensive if you buy it from VW/Audi) rather than through Bentley).

 

[Juanhmi]

I drive a '99 Explorer with the 4.0 OHV engine - quite a bit simpler. For awhile, I had one from the same year with the SOHC engine that I used as a parts car, and by parts I mean it had nicer interior trim pieces, seats, glass, assorted switches and electronics that I yanked out to make the OHV a much more comfortable vehicle.

For a brief moment, I thought I'd actually keep the SOHC Explorer, fix its engine issues, and have a nice spare vehicle. When I started looking at what it takes to do a timing chain job, or really anything else on that motor... it went to the scrapyard pretty quick. With the right socket adapters, plugs on the old 4.0 OHV are a really simple job. Most everything is, actually - there's just less to move out of the way. I think if Ford messed up at all on the design of these vehicles, it was introducing the SOHC engine at all as an option/trim level. I don't really think the few extra horsepower you got justified the obvious maintenance hurdles.

That being said, I'm sure those engines, properly maintained, are fairly reliable. I'm biased because that parts car I bought had every dang gasket blown in it from being overheated to death by the previous owner. I mean, when I thought I might resurrect it, I tried to fill up the radiator and every ounce of coolant I funneled in just poured out the tailpipe.

 

[FordJimbo]

Well, for all the hassles in this maintenance, I've vented my frustrations and will give praise to the durability. At 202k miles, it's now back to running very well. I still have to chase down some other gremlins but the vehicles runs strong, shifts strong, and drives and brakes well. I do like it.

The PCV was actually really simple after I figured it out and got my bearings. Less than $10 fix, including the PCV, a T-Connector, and some small length of hoses. I do appreciate that immensely.

The EGR and cleaning out the MAS and Throttle Body were quite simple once it's figured out and the biggest hurdle was the tamper resistant torx heads (still aggravating). Those 2 screws took longer than the tasks involved. Anyway, thanks for letting me vent. I'm really liking this little truck that drives like a go-cart and looks sporty.

 

[donalds]

Hay we have the same explorer same color to
But I got the dam sohc engine wish I could do more with this engine what was ford doing lol

^joke lmao

 

[RickOTR]

Would've been nice if Ford offered the V8 and a manual trans in the Sport. Much more power and fun to drive.

 

[410Fortune]

for the mas air flow screw you guys just grab it with some vice grips and turn, it comes right out. Replace it with a regular screw

I am seeing well over 250K miles from these SOHC engines.....with many more approaching 300-350K miles
Regular oil changes are the key, plus a dose of good luck.

There are SOHC engines on this forum with over 600K miles on them.............the bottom end of the SOHC engine is BOMB PROOF.

I offer a 5.0 and manual trans in a Sport, Im not Ford but it can be built rather easily given the correct parts

 

[jmops]

I recently purchased a well loved high mileage 98 Explorer sport with 4.0 SOHC. It has failed emissions, which wasn't a total surprise. So I've begun my tinkering mission to do some maintenance.

Please allow me to vent, as it will make my day much better... Keep in mind I'm not a professional mechanic, but I can tinker a bit to save on repair costs.

I'll just say that while I like the truck, the designers need to be scolded here for their unethical decisions and designs. I get really angry at engineers who purposefully design things to frustrate consumers. A few points. The proprietary torx anti-tamper screws on the Mass Air Flow Sensor really set me off. What should have been a 30 second removal was probably an hour of time trying to find a work around. They designed special screw heads, and they recessed them in a way to make it hard/impossible to get with pliers. So irritating, especially forcing consumers to buy special unusual tools which, in my case, meant putting hundreds of dollars of tools away (I was working in the driveway with a layout of tools), drive 15 minutes to the nearest parts store, spend money on proprietary parts, return, and dig all the tools out again, and start over. I finally just busted off the little protruding tip, and used other torx heads and vice grips and needle nose pliers. I'll be replacing these with normal machine screws promptly.

I replaced the EGR without too much difficulty but they again designed in in such a way that the angles and the proximity to the power steering reservoir made it more difficult than it needed to be. Removing the throttle body wasn't too difficult to remove, clean, and reinstall. Very straight forward, which I appreciated.

Cleaning the MAFS and throttle body and replacing the ERG should have taken 30 minutes, but took 2 hours due to the needlessly complex/poor design and placement.

This is the worse spark plug job I've done on a rear wheel drive car.... I could only get to the drivers side, as I lost daylight on the prior needlessly difficult tasks. I had to use multiple different extensions, spark plug removal tools, remove the dip stick, several different sizes of socket wrenches including an adjustable length ratchet... What should have taken 15 minutes took 2 hours and I was unable to complete my project before dark, and had to finish under artificial lights just to get the driver side done.

Next is the PCV and the passenger side, and I'm not looking forward to the passenger side... Apparently I need to remove the &^(&$%#^ WHEEL AND OTHER MATERIALS to access the plugs.

These simple tasks took probably 4 hours due entirely to a needlessly bad design for a shade tree mechanic, and I know that is a purposeful and unethical decision by designers or leadership at Ford Motor Company. Shame on them.

Thanks for letting me vent. I feel better now. And now it's off to tackle the PCV and passenger spark plugs...

I've had a similar experience with my '98 SOHC have started to search for other options like swapping for another vehicle that still meets my criteria (daily driver and body on frame, no off-road or super-power ambitions) or swapping the engine for one that is not so hard to work on. That led me to the GM Atlas engine series as typified by the straight 6-cylinder Trailblazer/Envoy platform and the straight 5-cylinder Colorado as being in the same power band as the SOHC. Make/brand issues aside, these are basically very good engines that have had their minor foibles shaken out over time. I haven't been able to find exact dimensions for any of them but they appear to take up less space then most V-type ones. They all share common features like true coil-on-plugs and NO EGR, both of which are address PITA design features of the Ford SOHC. Anyone out there that has taken a serious look at these as candidates for a swap?

 

[J_C]

^ Seriously? An engine swap to avoid doing EGR or plugs once in a blue moon?

Makes no sense to me on a semi-modern computer controlled engine integrating several electronics systems as well as the tranny. Now if you were going to delete everything or were looking for a long term project to make moar power...

 

[410Fortune]

the I force 5 cyl migh fit, usually inline 6's are too long for our engine bay

I have seen stranger things that's for sure