I recently bought an '06 4.2 V6 truck. I'm loving it so far. I got 18mpg on a recent trip. I did notice some light detonation at cruise though. A switch to higher octane gas had no effect. I'm thinking about going to a colder plug. Are the plugs hard to change in this engine? (I've been reading all the nightmare stories about plug changes on the forum.)

 

I have a 2003 ford f150 4.2. I changed the plugs on it, it was pretty easy. Didn't need any special tools or anything. I don't know how much they changed them in 06. Good luck.

 

it's easy to do on the 99 model, i can't speak for 06 tho

 

I would not change the plugs. 18 mpg is not that bad, and a little detonation is quite common.

Think about it: if a colder range plug would improve performance (MPG) you can bet Ford would have installed them from the factory.

I have 115,000 miles on my '05 and 18 - 20 mpg is about what I get this time of year. I think the switch over to winter gas has taken place and I always see a drop of 1-2 mpg when that takes place.

To answer your original question - changing the plugs is easy.

But I'd not be doing it unless you had 70,000 or more miles on the ones in right now.
I always use Motorcraft plugs and wires. Years of time here at FTE has shown those to be the best bet for Ford trucks.

 

Sounds like good advice to leave until 70K. I just wondered if this engine had the same issues with plugs that the V8 has. New concern today was a minor oil leak. I took it to the dealer and they said it was the intake or head! Thank goodness it's under warranty. Do these intake/head problems re-occur once you've had one? I've never had an engine problem that serious with any vehicle I've owned, and I've owned a bunch.

 

Oil leak? Nah, that is not something that is common at all.

The lower intake manifold gasket used to be a higher than normal failure item. But you don't hear too much about that any more.

Gosh, it was 10 years ago now that the problem was pretty common ('97 and early '98 models)

The lower intake gasket failed on my 2000 model at 155,000 miles. Got it all fixed and sold it at about 170,000 miles. It was running fine when I sold it.

All-in-all, I am very satisfied with the 4.2 and the F150. My current truck (the 05 with 115,000 miles) has had zero engine probs.
All I have done is replaced brake rotors long, long ago and replaced a leaking axle seal about 3000 miles ago.

Other than that, just routine maintenance.

I'd say, once you get the oil leak fixed, you likely have a truck that will last you a long time.

 

I think it's a good truck. Seems I got hit by the percentages gremlin on the leak. I know one thing, I've owned Lexus, Toyota, Corvette, and all of them had rattles and squeaks. My wife's Camry has vibration rattles. This truck is as quiet as a mouse in that department!
The service at the dealer so far has been stellar. It took them less than 30 minutes to diagnose the problem and they had a rental car waiting for me when they told me it would take a while to fix. They keep treating me like this and I'll have to replace the wife's car with a new Taurus!

 

same here. For all the talk about the quality of imports vs domestics, my two F150s have been to of the most reliable, trouble free vehicles I have owned.

From what I hear, they are nice cars. I like the look.

 

Brian,have you done any other PM yet? Like,trans,coolant,fuel filter? What mileage intervals did you do them at?

 

I got a call today and the dealer said the lower intake was the problem. I assume they mean the gasket. I pick it up tomorrow.

 

As a matter of fact.....

Two weekends back I dropped the transmission pan, replaced the filter and filled it back up with 5 qts of Mercon V. I average about every 30K-40K miles on the transmission fluid changes.

I do 5k mile oil changes. Generally use Havoline or Pennzoil (Advance Auto runs good sales on those two) and Motorcraft filter.

I changed plugs and wires at about 80K I think. so I have got some time left before those are due again.

I bled the brake system last month (@110,000 miles) so it's all fresh fluid in the brakes now.

I did a radiator drain and refill at about 60K, so I'll probably do another within the next 10K miles, give or take a few thousand.

Had a leaking axle seal, so I replaced that (@112,000 miles) and therefore the rearend got new lube.

All-in-all, I am NOT **** about maintenance. I just do the routine stuff and take care of it.

FWIW, I have a complete record of all maintenance I have ever done since the day I bought the truck in Feb '05.

I am now at 115,000 miles and still lovin' it!

edit to add- just re-read you post and am reminded: I need to change my fuel filter again. (about every 30K-40K for me) Thanks!

 

Now that's a bit suprising! I'd not sweat it though. Once it's fixed, you should be good-to-go.

Keep us posted!

 

Got the truck back from the dealer. I changed the oil and filter and drove it a good bit and then checked for leaks. It's tight as a drum now. While I was looking up under the engine for leaks, I noticed the edge of the new lower intake gasket. Man that's one heavy duty looking gasket! I also noticed water dripping from the two tail pipe connections prior to the cat while it was warming up. A turn on each clamp stopped that and amazingly quieted the deisel sound while at idle. A backpressure thing maybe? Anyway it runs like a top now.

 

The engine oil leak has returned. The exact same spot as before. Looks like it's back to dealer Monday. I'm betting on a head gasket this time. We'll see. Only 25,000 miles.

 

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