2007 Mercury Mountaineer 4.0L

[Dave9]

So I inherited 2007 Mercury Mountaineer with 190K miles and a replaced 4.0L 6-cyl engine. Know nothing about its history, nor why the engine was swapped nor the miles on the "new" engine.

This is the primary issue. All vehicles wear out but in this case it depends on how many miles on the replacement engine, whether it was (probably) used and how many miles on it before swapped in (if you can even trust what a junkyard/etc tells you about original miles), and whether (HOPEFULLY) new timing components where put on if not more.

Suppose it only had 100K mi when swapped in, new timing components put on, then you could be good for another ~150K mi from that point forward, or until the tranny fails. Replacement tranny could cost more than vehicle value, but it could still make sense if the rest is in good condition. I never expect a rebuilt tranny (besides Motorcraft crate) to last nearly as long on 2nd tour of duty. When the timing chain rattle at cold startup, starts, you typically have more than 10K mi. before it fails. Not always but we can only play averages.

Definitely take the seats out of they'll never be used, though you may then decide that you want a coated/covered plywood section added to level out the cargo area

 

[JustinH]

I'd trade in all three cars and get something decent, and be glad I got anything.

 

[pacem]

This is the primary issue. All vehicles wear out but in this case it depends on how many miles on the replacement engine, whether it was (probably) used and how many miles on it before swapped in (if you can even trust what a junkyard/etc tells you about original miles), and whether (HOPEFULLY) new timing components where put on if not more.

Suppose it only had 100K mi when swapped in, new timing components put on, then you could be good for another ~150K mi from that point forward, or until the tranny fails. Replacement tranny could cost more than vehicle value, but it could still make sense if the rest is in good condition. I never expect a rebuilt tranny (besides Motorcraft crate) to last nearly as long on 2nd tour of duty. When the timing chain rattle at cold startup, starts, you typically have more than 10K mi. before it fails. Not always but we can only play averages.

Definitely take the seats out of they'll never be used, though you may then decide that you want a coated/covered plywood section added to level out the cargo area

This is valuable info. The 4.0L engine is stronger, faster than I expected. I would not call that car slow. However, its MPG is almost in the realm of a V8 MPG. I get between 15-17MPG. I should try mid-grade in it. It's a fairly large SUV so I suppose it's to be expected.

No chain rattle just yet. Debating whether to keep it or upgrade. Thus far it runs with no issues.

 

[pacem]

I'd trade in all three cars and get something decent, and be glad I got anything.

My "dream car" if a 10-year old GMC Yukon XL 4WD. Basically a Suburban clone with some different features like 6.2L engine versus 5.3L. Ten year old because it has depreciated all it can and I am not going to invest 50K in a new(ish) Yukon/Burb.

 

[Dave9]

This is valuable info. The 4.0L engine is stronger, faster than I expected. I would not call that car slow. However, its MPG is almost in the realm of a V8 MPG. I get between 15-17MPG. I should try mid-grade in it. It's a fairly large SUV so I suppose it's to be expected.

No chain rattle just yet. Debating whether to keep it or upgrade. Thus far it runs with no issues.

Being OHC those really like to rev. It's a V6 but 4.0L isn't a small engine so you can't really contrast with the ~2.3L EB turbo engine offered on newer generations, and yeah, it's a heavy vehicle with a large boxy frontal area and high ground clearance, so I wouldn't expect even 20MPG except on the highway.

It's doubtful that mid-grade fuel would be worth the price difference.

 

[pacem]

It's a nice SUV. Internally, it's better built than the Tahoe. 185K on the odometer and drives straight. No rattles or noises, interior has held up well.
I do think GM has better internals, like the 5.3L and the tranny.. But GM also seems to rust more.

The Mercury is a gift from my mother who passed away a few weeks ago so it does have some sentimental value attached. The last vehicle she gifted me was in 1998 and it was a Ford Tempo. Which upgraded me from a 70's Dodge Dart.

Having said that, I see it for what it is. If the tranny fails (again) I am not going to fix it. Let alone the engine.
I can't get a solid repair history, one person told me it had the tranny replaced, the other that it had the engine replaced. If the latter, I am in good shape.
Is there a way to determine if the motor has been recently replaced? I would assume the new one got new water pump, belts, etc.

 

[01rangerxl]

I wouldn't worry so much about what ifs. Decide what your cutoff amount is for repairs (consider both cumulative and single big ticket repairs), and fix what needs fixing until you get to that point.

I don't even do that anymore, I just wing it. My 1997 Explorer SOHC gets driven 7 days a week and I would trust it to go across the country right now. 239k miles.

 

[pacem]

I don't even do that anymore, I just wing it. My 1997 Explorer SOHC gets driven 7 days a week and I would trust it to go across the country right now. 239k miles.

The same 4.0L engine?
That engine would be nice with a stick shift, it likes to rev I noticed.

 

[01rangerxl]

The same 4.0L engine?
That engine would be nice with a stick shift, it likes to rev I noticed.

Yes, though an earlier version that was even more prone to timing issues.

 

[pacem]

That design appears be junk through and through. Engine issues, transmission problems (I found out mine had the tranny replaced).
Now I should drive it until the wheels fall off.
It's paid for and it's free. Needs front brakes and then the seats will come out. (rear).

 

[michaelluscher]

That design appears be junk through and through. Engine issues, transmission problems (I found out mine had the tranny replaced).
Now I should drive it until the wheels fall off.
It's paid for and it's free. Needs front brakes and then the seats will come out. (rear).

If you wanted one that was even less reliable, the Lincoln Aviator had the 32-valve DOHC 4.6 L, out of the Mach 1 and Marauder, backed with a 5R55S

Then we can all cry in a corner with our Lincoln problems, with @GON 😭

 

[pacem]

What tune can I do to the PCM of this vehicle to make it slightly more awake?

I got the Diablo tuner for the 5.3L Tahoe and it made a noticeable difference, their "performance tune" that entails mid to premium octane gas. My Tahoe came with 3.42 gears and a bit sluggish. The MPG dropped to around 15 MPG highway-only.

I know I can do a custom tune but canned one seems just as good.

 

[Sneal46]

I am currently the owner of a 2007 Explorer with the 4.0. It was a fleet vehicle for a fire department and has been meticulously maintained. However, here is what I have done to it in the 2 yrs I have owned it (91k-128k miles on my watch).

1. Transmission rebuild. How could this be you say? Well it is not the transmission fault. The radiator was original and the tranny cooler inside had a crack in it which let coolant inside the transmission fluid which was not detectable until the gear wrench light went on. Before that, it shifted flawlessly.

2. Replaced thermostat housing with a new metal version. Much more stout.

3. New harmonic balancer. It was wobbling.

4. Water pump

5. Plugs/wires.

It runs great and gets me to and from the airport (100mi trip) when I need it. 4x4 helps at times too, even in the AZ desert.