Life expectancy for 4.0 SOHC

[Explorer_PL]

I have had my v8 for close to 9 years now and never read much about that wonderful piece of art from Ford called 4.0 SOHC. Now, that I got also 07 with v6 now with 116k miles, I need to get educated.

Can you guys post the highest mileage you squeezed out of the v6 before the timing issues ?
What is the most common failure on those ? Do I need to pull the motor out to do the rear cassette ? Are the guides the main problem ? I watched a video where the plastic pieces of guides fell down and blocked the oil pump and starved the engine of oil. Anything else I need to know about the ?
Tech by Trade - I hope for you to chime in (seriously).

Thanks

 

[boominXplorer]

Oil changes every 3k and ford oil filter is about all you can do. Highest milage on stock chains I have seen is about 230k. Usually the main tensioner fails somewhere after 150k but some people ignore it and let the pieces get down to the oil pickup.

I have seen plenty of even 97-98s even make it to 200k on stock chains, they all were taken care of though.

 

[ronwc]

I'm on my fourth V6 Explorer, 94, 00, 04 and now a 08, never had any real problems with any of them. All had well over 150k when sold. The 08 I have now has 174k on it, was fleet maintained, runs and drives perfect although gas mileage is bad (14mpg).

 

[Explorer_PL]

Thanks

So far that's encouraging

 

[Tech By Trade]

Lol, I see you have read the story. If you can swing a wrench you can keep them on the road for a long time.

 

[Explorer_PL]

Yes, I can change an air filter

My v8 looks so much simpler, I would not have a problem pulling the motor or tranny out, I am almost done with installing a new 5r55s in the 07, and I had my 4.6 out twice on the 06.

So if it comes to it, I could probably pull the 4.0 out, but the amount of special tools to do the timing scares me. Is t true there are no keys on the camshafts ? How are the sprockets timed ?

And I assume nobody makes metal guides to fix it once for good.

 

[Tech By Trade]

No metal guides, but if someone did it would be bullet proof. To time it there is a holder that blocks the crank at 0deg, then you set the cams to zero and tighten the cam gears and jackshaft gears in place. There is also a static tensioner that holds the chain at proper tension so everything lines up. Really not that bad to do, only thing that sucks is pulling the engine or dropping the transmission to get at that one little bolt under the flex plate. ONE BOLT!.......

 

[Explorer_PL]

...and catching it before the engine is toasted. I might drop the pan and see if there are any pieces in there already.

I wonder if metal guides would wear the chains faster and make the engine louder, maybe that's why they stick with plastic.

 

[chefduane]

I guess I fall into this category. I have 212k on my '98 SOHC 4x4 with stock chains. About 17k miles ago I did a pan drop when I changed the oil and found guide parts in the pan:

I have no significant rattle on startup, and once warm almost no rattle sound at all. But if you know what to listen for, it is there. Other than that she purrs like a kitten and runs like a top! I do meticulous maintenance at prescribed intervals and I'm sure that has something to do with its longevity but I know that its only a matter time before the chain skips and that's that. I have been doing 5k oil changes with Mobil-1 Hi-Mileage and Mobil-1 Extended Performance filters for as long as I can remember. I'm pretty confident she will get to 250k but beyond that its a crapshoot. And pulling the engine to repair the guides/chains is - 1. cost prohibitive, 2. beyond my capabilities, and 3. beyond my desires to keep the car. I've had it since new and am ready for a change. (I suggested that to my wife recently, but she did not appreciate my comments. Go figure ) In fact, I am currently shopping for a low miles '12 Escape Limited. I am going to downsize a bit as I no longer have the need for the size of an Explorer. The Ex will probably be donated to a charity or school to wrench on. But all in all I've had a great experience with my SOHC - daily driver, across the country a number of times, camping, dove hunting, etc, and no problems with the 4x4 in snow, ice, or weather of any kind. I am not as critical as others are about the SOHC, but as I said I do meticulous maintenance which some might not be inclined to do. Other than the timing chains she is mechanically sound and everything functions the same as the day I bought her. Maybe even better as I have done numerous mods (see sig.) Frankly, the emotional attachment is more difficult to get over than I thought. I'll be sad to see her go.

 

[Tech By Trade]

You know chefduane, Looking at those parts in your pan, they all look like they are off the front tensioner on the jackshaft chain.. That metal chunk is the spring, and all that plastic is the arm that puts force on the chain. Bet your timing chain cassettes are still intact. If you pull the waterpump and timing cover you could probably get away with a 40 dollar fix with gaskets and tensioner. Probably 3 hrs work. Only specialty tool would be a torque wrench and a Fan clutch removal tool.

 

[chefduane]

Well I have a torque wrench but not the fan clutch tool. What I lack is the desire to do it at this point. However, that still would leave the rear chain/guides/cassettes unaddressed that might grenade in the future. And besides, I've already set in motion the things to sell this Ex and get an Escape. But, I'm open to offers on it!!

 

[plasticseng]

I pulled my 2002 down at 257,000 miles and the only part broken was the balance shaft chain tensioner. Main, front, and rear cassettes all looked good.
I bought it new and changed the oil (Havoline oil, Motorcraft filters) every 3K for the first 150K and every 5K since.

 

[Mr. Alligator]

1997 SOHC. Got 340,000 before getting a rebuilt engine. Very consistent oil changes and easy driving. Also, some acceptance that it might implode any time. Spent some miles waiting for it to give up, but it did not... Finally decided to commit to another 100,000, at least, with truck, and got a rebuilt 4.0 SOHC. Now at 436,000, and mechanically sound.

Good luck.

Mr. Alligator

 

[plasticseng]

1997 SOHC. Got 340,000 before getting a rebuilt engine. Very consistent oil changes and easy driving. Also, some acceptance that it might implode any time. Spent some miles waiting for it to give up, but it did not... Finally decided to commit to another 100,000, at least, with truck, and got a rebuilt 4.0 SOHC. Now at 436,000, and mechanically sound.

Good luck.

Mr. Alligator

Awesome. I hope I can get to 350K with mine.

 

[08EddieCA]

150,000: Change oil every 3K. Randomly have the oil analyzed. Nothing has come up yet. Hope to get at least 200,000 out of it. Trans is on its last leg/gear.

150K on trans then internal failure - bands, gears, clutch, etc. Good luck over 150K. Proper fluid change early early early is key. No reverse. Slams between 2nd and 3rd. Shudders at highway speed. It's toast.

What are tag numbers when ordering a transmission? I simply thought I had to order a 2008 55r5s with a new torque converter. now I'm being asked tags. I don't know any so I cave them my full vin. Hope they can figure it out based on my VIN.

 

[seth21]

2003 V6 - just hit 180k with no engine failures. This engine still runs great and doesn't have any sign of dying at this point.
2008 V6 - just hit 100k with no engine failures.

*Both engines have had the radiator replaced and thermostat housing replaced due to leaks.

 

[Explorer_PL]

Eddie -

Are you talking about transmission ?

 

[08EddieCA]

Eddie -

Are you talking about transmission ?

Yes, sorry for unintentional hijack. Gave shop vin so I hope to receive correct trans.

 

[Explorer_PL]

That's OK, the one in the 07 v6 lasted 116k miles, the one in my older 06 v8 has 231k miles and going strong still.

 

[Erik Norin]

My 2008 eb 4.0 sohc got to 180,000 with no timing chain issues but broke intake valve spring. I was able to repair the head and went 40,000 more mi until the other side broke the intake valve spring and put the valve through the piston. Other than that no other issues. Mobile 1 is all she got from day one