4.6 Vs 4.0

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Apr 14, 2009 | 08:52 AM

filipows

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4.6 Vs 4.0

I am looking to buy another Explorer. I have had two 4.0 liter V-6's. I have been happy with them and had reasonable millage, 20 MPG with mixed driving.

What have 4.6 liter owners seen for millage or other comments on the V8?

Apr 14, 2009 | 02:45 PM

Steina

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From: Lake Havasu City AZ

I had an '02 XLT with the V6; got around 16 city and 20 highway unless towing, then it ran around 15. My '04 (239hp) gets around 15 city and 19-20 highway; towing improved to 16. If you're not towing, the V6 is fine but I prefer the V8. The newer V8s have 53 more hp so don't know what mpg they get.

Steve

Apr 14, 2009 | 03:26 PM

gcozmo

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From: Roanoke

We have an '04 with the V8 but I'm inclined to agree with Steve, if you don't need the V8 get the V6. We get about the same milage as the V6. We get about 15 city and the last 2 trips we took we got between 20 and 21 highway according to the on board computer.

Apr 14, 2009 | 07:39 PM

YoGeorge

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From: Detroit

Quote:

Originally Posted by filipows

I like both engines. Note that if you're looking at an '02-04 Explorer with the 4.6, however, that there is a TSB (03-25-6) issued on all Romeo 4.6 engines produced before 9/17/03 based on a problem with the valve guides in the rear of the cylinder heads.

I've got an '02 E150 with a Romeo 4.6 and had the heads both replaced under warranty (love extended warranties at times like this) at about 42k miles. Otherwise it would have cost bushels full of money. Not sure what the end result of the problem is, but the rear valves get carboned up and stick in the guides, so probably an ungood thing if you go for big miles with the Explorer.

So, a late '04 or any '05 Explorer should be OK, but an earlier one could have this issue with the heads.

And the '06 and up models may have the same "stuck spark plug" problem as the 3-valve 5.4's.

Good luck,
George

Apr 14, 2009 | 07:55 PM

filipows

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George

Thanks very much for the information. I am looking at an 06.

Can you fill me in on the plug problem? I could see how things could pile up on the plugs. Does water get in there and cause corrosion and sticking?

Thanks again

Dennis

Apr 14, 2009 | 08:10 PM

YoGeorge

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From: Detroit

Quote:

Originally Posted by filipows

Although I am not 100% sure that the heads on the 5.4 and 4.6 3-valve engines are exactly the same, there are a ton of threads on the forums here regarding the 5.4 in the F150 where the long shank of the plug sticks in its bore due to carbon deposits and rust, and the 2-piece plug breaks in half. BIG pain in the butt to remove--special tools, special procedures where you soak the plugs with penetrating oil. I actually asked (when looking for an Explorer a while back) if the 4.6 had the problem and it apparently does. Poke around the mod motor or '04-up F150 forums with some searches and you'll find some stuff.

I believe they got their act together by '07 or '08 for sure. And Champion makes a 1-piece plug that will fit the earlier motors if you can get the OEM plugs out. (Although I have found that Champion plugs kind of suck, I'd use them here.)

The '06 Explorer with the 4.6 also had some teething problems with the 6-speed trans with bad downshifts when coasting to a stop, etc. If you can get into an '07, I'd feel better with the 4.6 from that year.

Good luck,
George