4.6 Expedition high mileage

Discussion in 'Other Auto Tech' started by rgh96gt, Aug 8, 2007.

  1. I am looking at an expedition with a 4.6 engine. It has 139,000 miles on it. What are some of the problems these engines have when they get up there in miles? What should I look for? Thanks for the help.
  2. They are generally long lasting engines. Check to see if any smoke is coming out of the exhaust, ticks, knocks, also check the oil level and see if its full.
  3. +1; that's the story I hear about them. I've seen guys on here with motors around 200K and no issue what so ever. Long as you take care of it, the 4.6 is bullet proof.
  4. I have a 99 Expedition and now have about 160k + miles on it. No break downs yet.
  5. Some of them have problems with the passenger headgasket leaking oil, besides that its the usual wear and tear of any vehicle.
  6. take a small flashlight next time you go take a look at it. remove the oil cap and take a peek inside. it should be a light shade of brown, no black sludge. high oil change intervals will cause sludge that will hurt any engine no matter how bullitt-proof it is

    check the ATF fluid, if it's the original fluid it will be brown with a slight hint of red (use a white paper towel or napkin). if it smells burnt or looks like strawberry milk don't buy it.

    drive it and check for the obvious, smoke, knocks, wierd noises, etc. Ford trucks and modular engines in general are usually very reliable from what people who have owned them have told me
  7. Most of the earlier (pre-'99) 4.6's were prone to valve guide seals hardening and leaking above 100k miles, or with general age. If you get a puff of blue smoke when you first start it, or if you sit at idle for awhile and then take off (or go WOT after cruising granny-like for awhile), that's usually an early indicator of this. It's not a terribly catastrohpic sort of thing, but it will cause you to go through a bit of oil over time, fouls out your plugs, and will carbon up your EGR passages; you can get away with running thicker oil, changing plugs more often, and cleaning your passages more frequently, but ultimately you'll wind up having to replace those seals, and it's NOT a fun project. Expect to spend around $600 or so to pay a mechanic to do it, or waste a whole weekend farting around with it, if you try it alone - also helps to have a compressor and fitting to keep the valves from dropping.

    Also, if it has a plastic intake manifold, see if they're already replaced it with the updated design manifold that has the aluminum crossover. The stock plastic ones were notorious for cracking and spewing coolant without warning, until Ford came up with the revised intake. (Fleet vehicles were covered under the recall, but it may have already expired by now.) A new intake will run you around $250, plus misc. little stuff.

    Otherwise, as mentioned above, the 4.6 is pretty much a bulletproof motor. I hate letting go of my 4.6 T-Bird tomorrow morning, as it's a helluva solid motor, but my budget can only afford gas for one V8 car at a time... :(
  8. Expys dont have a plastic intake. It't all aluminum.

    I have a 97 with over 212K miles. Still runs well although it uses oil. Other than a broken shifter cable I haven't have a bit of trouble.
  9. Ah. Just assumed that they did, since the Crown Vic and Mustang 4.6's had the plastic intakes.
  10. Thanks for all of the info. The truck had been wrecked on the drivers side door. The paint on the drivers side and passengers side doors were orange peeled. Also, you could turn the steering wheel about 5 inches either way before the wheels would turn. The engine ran good though. I am going to have to pass. It is not worth trading my F150 for it. Thanks again.