Sohc is overhead cam. Usually ohv is used for the pushrod motor. Since they are both technically ohv motors some might be confused. I don't believe there was any confusion in this thread.

 

My 1999 Explorer has the 4.0L v6 OHV (over head valve) engine or the X engine according to the 8th letter in the VIN number which has one timing chain unlike the 4.0L v6 SOHC (single over head cam) engine or E engine according to the VIN that has three timing chains. I've had my Explorer for 9 years now because the car I had before it had an interference motor that ended up in scrap yard just after paying it off. Anyway, the timing chain went out on my Explorer about 6 or 7 years ago and after having it fixed it's been great up until recently, having hopefully transfer case problems and not tranny, but with the transfer case being connected to the back of the tranny probably be better to just replace both I think. Overall, it's been a good vehicle and the best part is, it doesn't have an interference motor. My first experience with an interference motor happened with a 2003 KIA that broke down in the middle of a long road trip far from home just as rush hour was starting. Had to push it about a block and a half with people honking at me even though I was on the shoulder. Had it towed to a repair shop and after checking out the problem the mechanic came up to me and said I'm really sorry Miss, but the timing belt broke.. I remember thinking cool that's not so bad knowing what I know about cars or thought I knew and was kind of happy, thinking it could be so much worse. Little did I know, it was worse, way worse! The mechanic noticed that I wasn't really that upset and asked if I understood what he said to which I replied yeah, the timing belt broke, no worries it can be fixed, no big deal. He said I don't think you fully understand, it's an interference motor. I was like yeah so, what does that have to do with the timing belt? He pulls out a diagram and proceeded to inform me that an interference motor has an over head cam system, in this cars case a dual over head cam which sits on top of the motor intead of the bottom so when a timing belt goes it shoves the valves and everything into the head because there's no room or clearance due to the cam basically taking up that space, unlike the old motors which had more room and a broken timing chain wouldn't destroy an engine. He said sure I could replace everything but it would always burn oil and be more expensive to fix then just buying another used motor, end result, junk. Now I'm not a mechanic, but what I learned that day was that an interference motor has an over head cam which means technically the 4.0L v6 SOHC would be one too I would think.. unless it has to have a duel over head cam or does having belts instead of chains matter for it to be considered an interference motor? I don't know, but I am gonna do more research now to be sure. Either way I don't want to own another vehicle with an over head cam even for better performance especially with having more maintenance costs on top of regular oil changes and tire rotations like replacing timing belts every 50,000 to 80,000 miles as recommended, unless you wanna end up like me that day, stranded and carless in the middle of nowhere, who needs that!
QUOTE]Since posting I have talked to 3 different Ford Dealers in my area and it seems they can't give a definite answer to my question. One says it is NOT an interference engine, one says it IS an interference engine, and the other says you need a Ford rebuilt engine either way.... What gives here I keep asking myself?

I'm hoping someone here can tell me for sure or if there is someone that has fixed one that has died while driving down the interstate and would no longer start.[/QUOTE]

 

Sorry, I can't tell you if the 4.0 OHC engine is interference or not. But just because it IS OHC does not automatically mean it's interference. It's a matter of how much clearance between the valves and pistons are designed into the engine. You can have non-OHC engines that are interference. But in general, the chances of interference increase with engines that are designed to have very high compression, where the combustion chamber is really small, and/or the pistons have pop-up domes on them, combined with very high valve lift.

Also sorry to hear of your engine failure, and how other motorists would rather honk at you than help you push your car out of the road. I have a similar story, where I got stuck behind a car that had stalled out at a right turn lane, and everyone was honking at me, thinking I was the problem. I got out of my car and helped the driver of the stalled car to push it out of the lane. As I got back into my car, I was met with more honking, dirty looks, and profanities. Some people really prefer to curse the darkness than light a single candle.