Ford SOHC 4.0 V6 engine RE: Timing Shenanigans

[IdaSHO]

For the record, Ive always loved the explorer/ranger platform. My DD is a high mileage 1st Gen Explorer.
But the SOHC 4.0 and its timing setup is beyond silly, and after this Ill never recommend owning one with this engine.
If this was my own vehicle, Id strongly consider a V8 swap. But thats simply not in the cards.

Hopefully this thread will help those that have heard of the problems, but don't fully understand them and what the project entails when they are do.
It really is not for the typical back yard mechanic. This is as involved as it gets for something as silly as timing chains.

This vehicle belongs to my parents, they purchased it new in 2005.
It has 235k on it, but super clean, and as factory original as you will ever find.
It is one of those that really is worth keeping original and on the road.

I'm doing the service on it to help them out.
All in, its about $1500 in parts and some specialty tools.
At my snails pace, and doing it 100% right, I should have 3-4 days into it total.

Ill let the photos do the talking.
If you have questions about this project, please ask.

 

[85_Ranger4x4]

That is a third gen.

Once you get past the rube Goldberg timing chains the sohc is a good engine.

I have never got past them, moms 02 Explorer had the same deal.

 

[IdaSHO]

Yep, this is 2005 4wd

Here are a few more pics...

 

[Buddha.]

The timing chain is at the back of the engine? What is this an Audi?

 

[IdaSHO]

There are actually FOUR chains on this engine.

One from crank to balance shaft (front of motor)
One from crank to jackshaft (front of motor)
One from jackshaft to drivers head (front of motor)
One from jackshaft to passenger head (REAR of motor)

yeah....

 

[IdaSHO]

 

[IdaSHO]

 

[Grassland]

Seems like something ford would engineer.
I don't know the maintenance intervals on that engine despite having owned an 08 Ranger
But I'd imagine even if it said "replace timing chain(s) guide and tensioners at 200k, once people see what's involved it's not going to happen.

 

[Buddha.]

That’s a clean engine.

 

[IdaSHO]

Yep. The entire car is silly clean.

CA car, maintained by an old guy (my dad) that lives by the 3k mile oil change montra, regardless of MFG recommendations.
Ive never checked, but this motor is likely a 5-7k mile oil change interval, per Ford, based upon driving conditions.

Id say its likely why things lasted as well as they did. But they still failed.

As I alwasy do before a large service like this, I still burned up a gallon of superclean and spent a solid hour pressure washing the snot out of the engine bay, undercarriage, and front end...
But it is very clean. The entire running gear, drivetrain, steering, and suspension.... Factory original.

 

[85_Ranger4x4]

Seems like something ford would engineer.
I don't know the maintenance intervals on that engine despite having owned an 08 Ranger
But I'd imagine even if it said "replace timing chain(s) guide and tensioners at 200k, once people see what's involved it's not going to happen.

On the earlier ones the engine tells you when it is time, not the book.

IMO it was a bandaid that shouldn't have happened to an old engine.

Shoulda just canned the 4.0 OHV for the 3.5 Duratec and moved on.

 

[XJLI]

Shoulda just canned the 4.0 OHV for the 3.5 Duratec and moved on.

So... the motor with the timing chain driven water pump that when it leaks mixes oil with coolant? With the 4.0 SOHC most of those trucks out of their useable life when they are ready for chains (as long as they've been maintained). My parents had one with 185K on it and so signs of chain issues, but that truck maybe only had another 40-50k left in it. Everything was pretty tired. OP's truck is a rare case.

 

[Mekcanix]

I did this to a buddies ranger. Swore right then and there I would never own a 4.0, nor would any family who's vehicle I have to fix. Nope Nope Nope. I figure the design team must have absolutely despised Mechanics.

 

[85_Ranger4x4]

So... the motor with the timing chain driven water pump that when it leaks mixes oil with coolant? With the 4.0 SOHC most of those trucks out of their useable life when they are ready for chains (as long as they've been maintained). My parents had one with 185K on it and so signs of chain issues, but that truck maybe only had another 40-50k left in it. Everything was pretty tired. OP's truck is a rare case.

My parents 02 Explorer needed them at 150k. 3k mile oil changes and the whole bit.

Knocking on wood my wife's 3.5 is running great at 270k.

In a truck stetting changing the water pump every so often wouldn't be a big deal.

Otherwise I would actively avoid a 4.0 sohc.

 

[Grassland]

So... the motor with the timing chain driven water pump that when it leaks mixes oil with coolant? With the 4.0 SOHC most of those trucks out of their useable life when they are ready for chains (as long as they've been maintained). My parents had one with 185K on it and so signs of chain issues, but that truck maybe only had another 40-50k left in it. Everything was pretty tired. OP's truck is a rare case.

That issue was related to transverse packaging. The "fix" was a weep hole so you maybe noticed before the second seal went, assuming you ever popped the hood.
In longitudinal packaging it's not an issue AFAIK