Any Long Term Experience with the 4.0 SOHC V6?

[north44]

I have an '03 Ranger with close to 300,000 km/~190,000 miles on the clock.

Under the hood, I've basically only replaced the alternator (twice), a fan clutch, the thermostat and gasket, serpentine belt, and a whole bunch of relays.

The a/c compressor is starting to act up, so a replacement is in the works for this coming spring/summer.

Maintenance has been up to specs in regards to fluid changes - oil, transmission, differentials, transfer case, coolant. Air and fuel filters changed every 50,000 km/30,000 miles.

Wearing parts such as brakes, bulbs, tires have been replaced as needed.

As I would like to keep the vehicle running for as long as practical, I am looking for any information regarding items that may leave me stranded (or worse) when they fail.

For example, I have heard that the crankshaft? or maybe camshaft? position sensor can damage the engine when it fails. What's your experience regarding the reliability of the timing chain?

It's been a very reliable truck, but with the mileage piling up, I'm entering uncharted territory, and would like to head off any problems before they crop up.

If you have any information regarding this engine's long term reliability, good or bad, I wouldn't mind hearing about it.

Thanks

 

[Sasquatch_Ryda]

The main problem with the SOHC is the timing chain cassets coming apart. You'll hears some pretty good rattling happening when they go.

 

[JohnnyO]

My sister just traded her '99 Explorer on a new one, hers had 165,000 miles on it and needed nothing other than oil changes and a rebuilt transmission. I'd lay money that it still had the original spark plugs in it.

 

[exbass94]

I don't think the 4.0 SOHC even has a camshaft position sensor. That's only a problem with the 3.0, not the 4.0. The early SOHCs had issues with the timing chain tensioners, but I think all the problems have been ironed out by 2003. So, you should have many more trouble-free miles with your engine.

 

[ChesterSPL]

I have an 03 4.0FX4 with 92,000+ and I am glad to hear that my truck will hold up for many more years

 

[north44]

I have an 03 4.0FX4 with 92,000+ and I am glad to hear that my truck will hold up for many more years

As with anything mechanical, proper and regular maintenance will generally keep it lasting longer.

Most usually, with moving parts, things mechanical, you get some indication that something is about to fail - something may be loose, there may be a vibration, a wobble, a sound such as a click, squeal, whine, growl, howl, etc. - and when you get these indications, you can take some steps to determine what is failing, and correct the problem before it becomes catastrophic.

With sensors, sending units, computers, wires, relays, things electronic/electrical, and so forth, it becomes more tricky.

Often these things are "all or nothing", "working/not working" - when they go, it's often suddenly and without warning - and you won't be prepared - a catastrophic failure with no clue it was about to occur.

And it's the surprise element that is the worst, because it will be always be at the most awkward moment.

I suppose that's one of the reasons for this thread: I was hoping to get a heads up, especially on anything that falls into that "catastrophic failure" category, that would leave me stranded, or worse, when/if it fails.

 

[NicoNO82]

worst problem ive had was the *explicit* *explicit* *explicit* *explicit* *explicit* *explicit* *explicit* *explicit* *explicit* *explicit*, cost me $1300 *explicit* *explicit* god damned fuel cutoff saftey bullshit fucking button switch.

shop told me, "OH, uh prolly the fuel pump well replace that itll be 1300 dollars." Im like fine whatever fix it so i can get back to work. one week later same problem and lo and behold damn fucking swithc terminal overheated? and melted... WTF! i cut that bitch out and spliced the wires ti work perfectly now. I bet they didnt do shit for that $1300. my dada says i should contest it. im like i dont have time to argue.

next time i get hit so hard in my truck that fuel continues to flow to the engine bay and ignite as it sprays onto the nearest sparking ignition source and burns me ruthlessly as i try to crawl out from underneath this 5000 pound hunk of wrecked metal i will curse my decision to eliminate this "safety" measure... until then i will be happy it doesnt leave me stranded on the interstate and cost me $1300.

 

[95offroadx]

Thats impressive, my 03 ONLY has 121,xxx miles on it! replaced the orig. clutch at 110k miles. Good to hear they last that long!

 

[north44]

worst problem ive had was the *explicit* *explicit* *explicit* *explicit* *explicit* *explicit* *explicit* *explicit* *explicit* *explicit*, cost me $1300 *explicit* *explicit* god damned fuel cutoff saftey bullshit fucking button switch.

shop told me, "OH, uh prolly the fuel pump well replace that itll be 1300 dollars." Im like fine whatever fix it so i can get back to work. one week later same problem and lo and behold damn fucking swithc terminal overheated? and melted... WTF! i cut that bitch out and spliced the wires ti work perfectly now. I bet they didnt do shit for that $1300. my dada says i should contest it. im like i dont have time to argue.

next time i get hit so hard in my truck that fuel continues to flow to the engine bay and ignite as it sprays onto the nearest sparking ignition source and burns me ruthlessly as i try to crawl out from underneath this 5000 pound hunk of wrecked metal i will curse my decision to eliminate this "safety" measure... until then i will be happy it doesnt leave me stranded on the interstate and cost me $1300.

I've read that the inertia cut-off switch can act up - seems to be a fairly common occurence - found a lot of information/threads on it in my searches through various forums. I'm sure your experiences with this fairly simple part will give readers some food for thought.

Any fuel system delivery problem seems to be both time consuming and expensive to diagnose/repair.

I had a problem with relays in the underhood fuse box about a year ago - after they started failing (of course one at a time, over a period of a couple of weeks to a month) I just ended up replacing all of them.

I can only figure that it was a bad batch that I got in mine since I have never encountered relays failing in batches like that.

The first time a relay failed and I had a "no-start" situation, it was a real PITA to diagnose. Sometimes the engine wouldn't turn over - intermittent problem - went through step-by-step examining the starter, battery, ignition switch, fuel pump, etc. Finally got to the source of the problem which was probably one of the simplest - a relay (the starter relay to be specific) was acting up and failing intermittently - replaced it and it was OK.

About a week after that, when the engine was cranked over, it sometimes wouldn't start - but eventually would after two or three tries. It did this about 4 times in one day, and the last time it happened, it wouldn't start even after 5-6 cranks.

I replaced the fuel pump relay, and it started up like a charm.

Any electrical problems, I'll replace a relay for it (if it has one) first (after examining the fuses) before I go further.

 

[jmg8550]

Yeah those timing chain cassettes can start to act up. When you start hearing a tick in the valvetrain, better get it checked out asap! otherwise the engine can suffer severe damage. special tools are required to do the job. and if you have problems with the chain in the back of the motor. might as well pull the motor out to change it. the tools cost about $300 for the set.

 

[north44]

Yeah those timing chain cassettes can start to act up. When you start hearing a tick in the valvetrain, better get it checked out asap! otherwise the engine can suffer severe damage. special tools are required to do the job. and if you have problems with the chain in the back of the motor. might as well pull the motor out to change it. the tools cost about $300 for the set.

Thanks for the "heads-up" - I appreciate the information, and a few other people have also mentioned the associated noise indicating timing chain cassette issues.

It a big job, even to get at the timing chain, and by that time, I'm sure there would be a whole bunch of other stuff to do while the engine is out.

Knock on wood, no unusual noises from the engine yet - just checked the oil today (due for a change in a couple of hundred kilometers/miles), and it hasn't burnt a drop in the last ~5000 km/~3000 miles.