Mountaineer 4.6

[Digitalgp]

Good to see we’re back. Ive been looking at a mountaineer with the 4.6 to replace my explorer which only has 60,000 miles on it. I know the 4.6 has an issue with the spark plugs breaking and being this low miles I’m betting they are still the originals. How much did that cost to fix?

Also are there any other things specifically with the 4.6/6-speed drivetrain I need to lookout for? What kind of gas mileage are you seeing with the 4.6 awd combo?
Keep in mind I am coming from an ‘07 explorer with the 4.0.

 

[Bill MacLeod]

There was a change sometime in the 08 model year to correct the spark plug issue. What year are you looking at.

 

[94Eddie]

As Bill stated, the spark plug issue only applies to 2006-2008 V8s. I know for sure the 2009-2010 V8s have the one piece plugs from the factory. If you have the older plugs expect anywhere from $500-$1,000 for a shop to change the plugs depending on how many break.

A few things to check for is a leaking radiator. Some leaks are slow ones and are hard to spot. Check for worn wheel bearings. Pull any trouble codes that might exist. Check to see if the air recirculation flap is working properly as this is a very expensive, or time consuming, item to repair. The 4.6L 3V and 6R60/80 drive train is very reliable if maintained well. I get 20-21 mpg at 60-65 mph and mpg at around 18-19 mpg at 75 mph. Also, I highly recommend immediately doing a transmission pan drop, filter change and refill. Then doing the same every 40k miles. It wouldn't hurt to do full swap of all fluids before 100k miles hits.

 

[Bill MacLeod]

Everything 94eddie says. Trans fluid, filter is a must. SP in a 6r, LV in an 8r. Pan drop only do not attempt a flush.

Just checked with a Ford Tech, here's the info on the plug/head change:

TSB-08-7-6 for 4.6 engines build date after 11/30/07 ...is the change over. But its engine build date not vehicle build date.

I didn't verify info. I trust him, he's my son and if incorrect, someone in for an azzkicking.

 

[fireftr]

Good to see we’re back. Ive been looking at a mountaineer with the 4.6 to replace my explorer which only has 60,000 miles on it. I know the 4.6 has an issue with the spark plugs breaking and being this low miles I’m betting they are still the originals. How much did that cost to fix?

Also are there any other things specifically with the 4.6/6-speed drivetrain I need to lookout for? What kind of gas mileage are you seeing with the 4.6 awd combo?
Keep in mind I am coming from an ‘07 explorer with the 4.0.

I’v

 

[fireftr]

I’m the original owner of an ‘05 Limited Ex.
Yes, ejecting spark plugs is one of the issues with the 4.6.
Replace them if they’re OE..
Cost me $350 to get repaired ( heli coil to fix stripped threads in head, new plugs and new coil pak, since the rocket plug broke it) Had to replace intake manifold, problem with it being made of plastic.
Rebuild trans, rear bearings, rear diff whine.
Fortunately, I did a lot of the work myself, saving a lot of labor $$$.
Have 205k on it, but still love it!
Still runs like new. QUOTE]

 

[Bill MacLeod]

fireftr: Completely different issue with the 3valve engine. Completely different plug that will seize to the head with carbon buildup and breakoff if not removed properly. You then have a broken plug seized to an aluminum head. Can get very expense. All 3v 4.6 in model years 06 & 07 and looks like some early 08's.

 

[Digitalgp]

I am looking at an ‘08 not sure on build date. I do have a connection in the shop of a local ford dealer he says there is some sort of special tool they have there for it but was busy so didn’t get to chat much. Gas mileage isn’t far off from what I got with my current explorer. It would be a shame to have to go though wheel bearings again especially after replacing all of mine with new ford ones within the past two years

I’m going to look at it sometime this week so depending how it checks out...I’ll see what happens.

 

[94Eddie]

I am looking at an ‘08 not sure on build date. I do have a connection in the shop of a local ford dealer he says there is some sort of special tool they have there for it but was busy so didn’t get to chat much. Gas mileage isn’t far off from what I got with my current explorer. It would be a shame to have to go though wheel bearings again especially after replacing all of mine with new ford ones within the past two years

I’m going to look at it sometime this week so depending how it checks out...I’ll see what happens.

There is a tool that allows extraction of broken plugs. It just adds to the time for the mechanic to complete the job. There are a lot of YouTube videos on this and how to decrease the odds of breaking a plug.

 

[Bill MacLeod]

There is a way to tell what plugs it has. When you go to the Ford Parts Dept't they will ask you to identify or bring 1 of the coils to them. They can chased down serial # to build date to engine build date, but that may take time that they are not willing to do for you.

If the 08 still has Ford coils, (Ford oval and part # stamped on top) the coil boot is either brown or black. Brown is new style head, black is old style head. If still not sure, than plug has to be pulled. New style is very long and threaded basically to the end. Old style is threads an 1" or more that a barrel/sleeve about 1 1/2" long. The barrel/sleeve is the issue. Ask whoever has this truck to pull a coil so you can see for yourself.

You can go to rockauto, pull up the plugs and see the difference for yourself.

Have you test driven it yet? What's the mileage?

 

[94Eddie]

When I was looking to replace my 2002 Explorer I only considered 2009 and 2010 V8 models for three main reasons. Reason one was these models had the 6R80 transmissions that are slightly beefer than the 6R60 in the 2006-2008 V8s. Reason two was the spark plugs were sure to be the one piece design that all but eliminates the breakage issue. Reason three was these years seemed to have less issues with deteriorating insulation in their wiring harnesses.

 

[Bill MacLeod]

I agree that a low mile 2010 V8 would be the one to find. But 06 model was high products year of V8's, then 07, then 08 then 09 then10. The production # fell dramatically.
But I would not shy away from a low mile 06 to 08. There may be a "jewel" out there. And it may be worth checking-out.

 

[94Eddie]

Luckily I had plenty of time to find a replacement. I shopped around for 2-3 months before finding a good prospect locally. If I were willing to travel a little I could have bought a low mileage (50k-60k) 2010 V8 very quickly for around $10k-$12k (price before haggling). Waiting got me one in very good condition with a little over 100k miles for around $6.5k that needed a new radiator and tires.

 

[loooney2ns]

If you send me the vin number, I can tell you what plugs it has.