I've owned the truck for 15 months and only put 7000 miles on it since she's the weekend workhorse and not a daily driver. That said, I've just recently cracked 200k, but without a full service history I'm wondering how far I should go on additional preventative maintenance.

2002 XLT SCab, 4x4, 5four.

Items I've done so far:

• Transmission pan drop, filter replacement, refill.
• Removed K&N intake and replaced with factory yard pull.
• Drained and filled rear axle, replaced diff cover.
• Dropped driveshaft and replaced U-Joints (they were toast).
• Replaced pinion seal, was leaking.
• Drained and filled transfer case.
• Replaced front and rear pads and rotors.
• Replaced front upper control arms and shocks.
• Patched/Painted rust hole in side of box behind right rear wheel.
• Replaced thermostat, old one opened at 165*.
• Regular oil changes at 6 month intervals / air filter also new.
• Replaced IAC due to idle issues in cold weather, problem solved.
• Replaced PCV valve because I think the old one was non-motorcraft.

Definite need-to-do list:

• Cooling system flush/fill/bleed.
• Brake bleed.
• Begin attacking rocker panel rust spots.
• Needs new tires this year.

On the fence about:

• Replacing plugs and coils.
• Replacing O2 sensors.

Since I don't know the service history, I feel like I should do the plugs, coils and O2 sensors. I'm also a cheap bastard. The current coils are motorcraft as are the plugs. I only pulled the plug on #1 and it looks ok to me, maybe just a little whitish. No pending codes, no misfires. Cats are original... not sure how old the O2 sensors are, but they look old from the outside.

It's running pretty well, but I also want her to last a while. It's a real luxury having a third vehicle around for weekend tasks, hunting, going up to camp and commuting in the snow. I really wouldn't want a payment on a new(er) truck for something I drive so little. Is the ~$400 worth it for plugs/coils/sensors since I have no idea when they were last touched? I'll do the work myself, of course. Anything else I should be thinking about?

 

Forgot to mention that the fuel filter looks like it was replaced shortly before I bought it. No issues, so it didn't make my current list.

 

Huh, looks good, lots of work. But , you know what to do, that's for sure. That damn body work slows me down. I've had the parts for a couple years now, but other things come up and get in the way. Purchasing another truck pretty soon, perhaps then I'll tear this one apart lol.

About the oil change intervals. A little about oil and these engines, -The crankcase is a sealed system. So you could go 10 years without changing the oil if you don't put the miles on. That's old school thinking, so many miles or 6 months whichever comes first. Not so with these engines. However, if you store the truck and occasionally start it and let it idle, that is very bad for oil and engines. That's because you'll build moisture without burning it off. That contaminates the oil quickly. For this reason, when storing, the vehicle should be run on stands for 20 miles every 3 months. Running them 20 miles like at say 50/60 mph burns off all residual by product...moisture. Maintains the seals as well. Yea, it takes a VERY long time for oil to breakdown on it's own, specially in a sealed system.

 

Coolant for sure
You might proactively replace the radiator and fuel pump and alternator. The alternator and fuel pump will eventually die, and the radiator is cheap insurance.

 

I change mine once a year in late May weather it needs it or not. I like having fresh oil in the summer. I usually dont put 6.000 miles on it in a year.

 

Thanks for the point about the oil changes. I didn't consider that low mileage trumps age with a sealed crankcase and synthetic oil. Fortunately, the truck almost never makes a short run. When I do drive it, it's minimally a 30 minute drive to wherever I'm going (usually camp or work, both are over 20 miles away).

Radiator, fuel pump and alternator are all good ideas too. I'm not sure about the fuel pump, but the alternator and radiator are original.

 

Yea, that's perfect. What kills the oil is letting them idle for a bit, then shutting then down and short trips. That more less waters the oil down and compromises viscosity. 20 miles is enough to cook off by product naturally.

When it doesn't cook off you'll notice a white milky substance under the oil fill cap (many have mistaken that for a bad head gasket...not so). What you don't see is that crap also covers the inside of the cam covers (valve covers) at the top. It can get pretty thick, specially during the winter. Serious contamination....you don't want that.
If that occurs by chance, you'll need to take it for a long drive, then immediately change the oil when you get back. It's an engine killer that usually occurs because of short trip syndrome. If all the vehicle does is short trips, you would HAVE TO bump the oil change regimen. To like say every couple thousand miles or just monitor the inside of the valve covers in cold weather. Seems like a lot, but most vehicles are driven enough to where this isn't an issue.

At 346,000 miles I'm still using the original Alternator and dual core Radiator. But, either could go at any time. It's unusual for an Alt to last that long. I've changed the brushes a couple times and installed a HD regulator, but that's about it. The radiator not so much IF your good about coolant maintenance and don't run into any electrolysis issues IMO. A fuel pumps normal life span is 90,000 miles. It's been that way for as long as I can remember lol. But they can defy all odds and go much further.

 

The key to fuel pump life is changing the filter. If your filters been clogged fuel pump replacement isnt usually far off.

 

The sock filter on inlet falls apart and crud in tank damages check valves. Or clogs pump suction.

When ethanol was introduced, it literally caused sheets of varnish stuff built up on walls to fall off into tank.

But, they tend to just wear out. I've replaced fuel pump on several vehicles 200+ k miles.

 

Yea, should replace those socks. I cleaned mine the best I could the last time. It's kind of impossible from what I recall lol. Couldn't believe how dirty the tank was inside. It wasn't grimy, just a lot dirt or grains of sand.