OK, I know most people here are of the ..."Just replace it with a 5.4!!"... mentality, but I don't want to do that for the primary reason of poor mpg out of them. I'm to the point where my existing 4.6 is breaking 20 mpg now, and it's beginning to show its problems of age and poor maintenance from its original owner (I bought it at 130k, it now has almost 150k).

I was looking at remanufactured.com's DFZF motor for the '01 to '03 trucks, and was wondering if anybody here has dealt with these people before. I'd like to go with that motor as it has the PI heads, but I don't know about what else I'll need to keep from my motor. I just emailed them asking such, but was looking for y'alls opinions. Thanks

 

Never mind remanufactured.com. They say they can do custom remanufactures, but yet I just got an email from them saying they can't do it. Go figure.

I HAD been thinking about getting a complete, newer, jyd core and simply pulling it apart, swapping my non-PI cams into it, adding a set of TotalSeal gapless rings to it, and calling it good. If I were to go that route, though, I'd need a full set of gaskets as well as head bolts (they're torque-to-yield, and once removed need to be replaced. I DO know that), as well as a gasket set, which I've been told is expensive as H.

Anybody have some better-priced parts sources for these goodies they'd like to share?

I was trying to get by with this truck for another 150k-200k, and want the best fuel economy I can get out of it for those miles, figuring the 4.6 being the better motor for that purpose.

 

honestly, the 4.6 doesn't get very much better fuel mileage than the 5.4L. The 5.4L also produces much more torque down on the bottom end, thus it won't have to work as hard under load. Therefore, under load, the 4.6 will really not be getting any better fuel mileage at all than the 5.4.

Swap to the 5.4L. You won't regret it.

 

Wow, only 130,000 miles and it needs a rebuild?? It must have really been abused in it's early life..

My 97 5.4 is just about to roll over 187,000 miles and it's just as strong as when I got it over 6 years ago @ 62,000 miles on the clock...

Now, I've never driven a 4.6 in an F150, so I can't compare them.. I had the choice of a 4.6 or a 5.4 when I bought mine and I took the 5.4 even thou it had more miles on it, needed new tires and cost a tad bit more then the 4.6! I'm so glad I did..

What do you do with your truck? If you just drive it, then the 4.6 is probably the way to go.. Don't think that just because the 5.4 is a larger engine, it will automatically get less mpg's.... It's all in how you drive it and what your driving habits are.. I average 15-16 mpg on my commute to work and back and that's a mix of hwy and city driving.. Not bad for a 40 mile a day round trip and most of that is stuck in rush hour traffic!

I also tow a #5000 TT, so even thou the 97 5.4 has the least amount of power of the 5.4's, it still does very well with my TT and I have no issues at all..

Sorry, I can't help you on your actual QUESTION! I just wanted to comment on the mpg part and brag about my high mileage 5.4!

Way off topic, but I watched a YouTube video of "Top Gear" and one of the segments was on the mpgs of a Prius and a BMW M5 (V8 with 400 hp...).. They drove the Prius around their track as fast as it would go and had the BMW follow. After so many laps, they compared mpgs and the Prius was around 17 and the BMW was well over 20 or 25 mpgs I think..

Anway, good luck with the project!

Mitch

 

I'm up to over 20mpg with it as it is, but when parking it in gear on a grade, the truck rolls back, jerkily. That tells me COMPRESSION. I'm not real inspired by the condition of the clutch, either. The truck is currently sitting just under 150k (I BOUGHT it at around 130k) and I feel it needs something. I tow, but VERY infrequently. The truck is mainly for daily driving and winter busting. I found a 2002 F-150 4.6 for $1000, but if I do what I want to it, which is very minimal, actually, it's the need for new head bolts and a full, high dollar gasket set that suddenly increases the price of the project to where I'm not real sure I want to do it. It'll still be WAY cheaper than a "newer" Avalanche, and it'll get WAY better mpg's.