Cross posted from the automotive board. Not much traffic over there.
My son is looking at buying a 2002 Ford F250 with 7.3L diesel. Wants it for a ranch truck. What should he be looking for when inspecting? Should he get a compression test done on it? Any other sort of tests? It has 186K miles on it. Carfax is clean. He's already asked about the injectors and if they have been replaced lately.

Thanks in advance.

In 13 yrs of owning a 7.3, the only problem(s) involved the high-pressure injection pump. Not sure how that can be "checked", as likely it will work till it doesn't...

Edited to add: as mentioned below, camshaft position sensors went out on a regular (2-3 yrs) basis, until a long-life unit finally came out.

Depends on how in depth he wants to go, but the biggest things I experienced with my 2001:

1. Water pump, Ford has a crappy design on the water pump. I went through 5 of them, so check the pump and connections for leaks

2. Fuel filter - check the fuel filter/water separator on the back side of the filter housing for leaks on the o-ring. The valley in the v-8 will hold about 2.5 gallons of fuel (ok, exaggerating some - probably closer to 3 quarts) when the o-rings begin to leak. The dealer will rip you the hell off replacing the water separator unit, BTW.

3. If it's 4wd, check the auto hubs. Ford's system on those were vacuum operated and they were notorious for failure when the vacuum system developed a leak. I replaced mine with Warn manual hubs and never had a problem after.

If you really want to get into detail, you can get the turbo inspected - basically pull the hoses and manually spin the turbo fan and check for any slop or wobble. Shouldn't be any with those few of miles. You can also get the injectors looked at, i sold my truck with 412k and it still had original injectors, so there's that.

Had a '96 and '03 7.3's.......kinda wish I hadn't sold either.....

So far as the '03 goes, pretty sure I only replaced the water pump once, a camshaft position sensor, a front wheel bearing assembly and U-joints. Other than that, just the typical stuff that wears with use. Guy I sold it too had to do something (don't recall what it was) due to the 4WD not locking in.

I'd spend a couple hundred bucks (or whatever) to have a trusted mechanic give it a once over. Then drive hell out of it if I bought it...good pickups.

I have a '97 I bought new, F350 crewcab 4x4. I replaced the auto locking hubs with Warn manual hubs when the factory ones broke. Replaced the clutch at about a 100 thousand and just replaced the high pressure fuel pump. I have 180 thousand on it and it still runs strong.

I have an 03 and have previously had an 01. There will probably be oil in the valley which leaks from the o-rings on the High pressure oil pump or the o-rings on the turbo. For a ranch truck, it's probably easier and more cost effective to just let it leak. It's not a deal breaker, totally normal for that mileage. All oil in the valley will drain down the back of the engine and drip down by the transmission and look like a rear main seal leak. Rear main seals hardly ever leak on these engines and it's usually just turbo pedestal O-rings or hpop O-rings

I would take off the oil fill cap and put it over the fill tube upside down with the engine running. It should not get blown off by the gasses coming out of the tube. If it gets blown off the engine has too much blowby and has compression issues. I would also get him to cold start the engine and make sure it doesn't idle rough when cold. Other than that, make sure transmission shifts good.

I'd be happy to answer any more questions.

Also X2 on the fuel filter housing o-rings leaking and crank position sensors. I've had those on both trucks. They're great trucks but they just need a little love every now and then!

-Jacob

buy from an individual not a dealer... apparently there are some real cheats out there. Have the early model 99 250 and a 01 350 standard both 2wd. Cam position sensor is the only thing that has left me by the side of the road. Water pump,Idler pulley and belt tensioner can go anytime after 150k, the water drain valve on the fuel bowl will leak after 15 years. 7.3's are noisy as all get out but will run forever with a little care. And the paint on the hood and cab will scald if you park them for extended periods in the Texas sun.

Having worked on these engines since 1984, they were 6.9 IDI then. First look for oil leaks, this will tell you a lot about the engine. Ask the owner how often he did oil changes and what type of oil he used. Ask the owner if he has maintenance and repair records on the vehicle. Check the radiator fluid to see what it looks like along with transmission fluid and color. Smell the oil to see if it has a diesel smell if it does, walk away, you will soon be replacing the engine. Smell the transmission fluid to see if it smells burnt. Be sure to check the front end for wear. At that age of vehicle and mileage you may have a lot of parts that are worn. Drive the vehicle and see how it drives and rides. Check AC and heater. If you get serious have the vehicle inspected by a mechanic that you trust and will give you a complete report for a few hundred of dollars. This will be money well spent. Hope this helps.