mperl

New to me, 2005 F150XLT, 4.7V8 2X. 178,000 miles. Everything seems to work ok except no compass reading. Truck was fleet owned, one company. I have no definitive service history but Carfax says no accident, shows routine main. Truck starts ok, runs ok, shifts ok. No leak. I did an oil change and new serpentine belt. Should I drain and fill the transmission fluid? Drain and fill the radiator? Change spark plugs? Timing belt? Or just let things be until I sense trouble. It does feel a bit sluggish, but I read the 4.6 is normally a bit sluggish. Thanks.

LariatDude

Honestly do everything you mentioned. Transmission, rear diff, transfer case (if applicable), replace coolant, spark plugs (if you don't know if they've been changed), and maybe check the battery as well. Timing should probably still be fine. Call it a whole bunch of extra work but at least you know what got changed when and that you had it done. I bought my truck and was told oil was changed 2 weeks prior, after driving it home I made the mistake of checking the dipstick only then. Oil didn't even register on the stick, probably had maybe 2 quarts from what I could tell. Plus the oil looked dirtier than clean.

Summers22

iTrader: (2)

Do you want it to be reliable? If so, make sure it will be. Change all fluids, filters and do a thorough tune-up and replace any worn suspension parts. You do that and you will get another 100K out of it pretty easily.

650NutKase

For reliability, the 4.6 is the better engine. If it were mine, I'd dump and refill all fluids and change filters, air, oil, fuel, etc. No service needed for the timing, it's a chain.