Originally Posted by Tenn01PSD350

Ok all. This is my stab at streamlining the what to look for when looking at buying a 99-03 PSD truck. I will take the first stab at it and would like all of you to throw in what you think is specific to these vehicles. Some of it may be vehicle nonspecific but useful nonetheless.

My intent is to compile ideas (aka brainstorming) then cut and paste into one item. Can we do this Scott, Dan? Don't want a lengthy thread and I don't feel like doing a forever search. I know how it is searching for things here sometimes.

I will break it down into categories:

1. Visual: Body and rust are obvious items, nonspecific.

A. Engine

1) Check for any obvious fluid leaks, especially the engine valley, tranny weep hole area, and around the turbo and pedestal.

2) Check coolant with strips and find out the record of any changes or water pump replacement based on mileage.

3) If possible, do compression check, and Cylinder contribution test.

4) Inspect turbo inlet side vanes, should be straight and not dusted or jagged. Try to move the shaft in and out and up and down. Any real noticeable movement by hand is bad. Open and inspect air cleaner assembly for an idea of how it was maintained.

5) If possible, have fuel pressure tested at engine to check pump.

6) Check all intake /intercooler boots for residue or leaks and correct before trying to determine engine condition.

7) Look at oil pan for notorious rusting, make sure not beyond repaint type repair.

8) Know whether you're getting forged or PMRs. 99-mid 01 = forged, anything later is possible or for sure PMR. Not an issue until you exceed 400HP.

B. Transmission, driveline and 4x4 system.

1) Look for any obvious leaks.

2) With the system in 2wd, grasp and rotate both front drive axles and ensure they rotate freely. Go to the hubs, ESOF and manual should rotate from lock/auto to free with no problems.

3) Grab rear driveshaft and push up and down along it's length checking for worn u-joints or bearings.

4) Check front and rear differential levels. (An indicator of maintenance) Level should be at or w/in 1/2 inch of check plug.

2. Test drive. If you have never owned a 7.3 PSD, try to get a 7.3 owner to test drive it. I did this with a friend who bought his new. Invaluable evalation because you have no idea. A stock PSD may feel like a slug to the gasser uninitiated but it can pull a house off of it's foundation. So here we go.
A. Drive more than one PSD truck that you are considering. Whether Auto or Stick, it will give you an idea of the overall condition of the one you want to buy. Cost = 0. Learning curve = super high. Dealers have a ready supply.

B. Startup. Turn key and watch wait to start light. The colder it is the longer it will take but should take no longer than 15-20 seconds on even cold days. Start engine. Should crank readily and turn the tach while cranking (although mine does not). Should start within 2-5 seconds of cranking. The colder it is the longer it will take but if longer than 5 seconds there may be a problem. Even in colder weather. If it does not not start easily on the second try, suspect problems, possibly in the glow plugs or GP relays. If it does not crank readily, or seems to drag, suspect batteries first, starter next, then cables.

C. Driving. Check all operational items. Don't be rushed. This is a major investment and you want to get it right. Even small items like the cruise will set you back.

1) Auto tranny: will feel like it takes the throttle to get moving with a stocker. The higher the mileage, the worse this will be. The shift should be smooth but slippy with a stocker. Long to engage. Convertor lockup will be almost imperceptable, but there. Will lock up at about 45 to 60m depending on throttle in OD. Should drop out of OD with input to brake or reduction of speed.

2) Standard: give input

3) Ride: if it is bouncing down the road, you can look to having some problems to take care of. These can be tire balance. Tires, or some unexplained seemingly incurable symptom that you may have to live with which is unacceptable and not common, but does happen. Some say it is an out of balance driveline but there is no universal cure.

4) Exhaust drone. Only happens with aftermarket exhaust due to what I believe is harmonics resonating in the thinner walled aftermarket systems. Not a big solution at present but not a performance issue.

5) Performance. There is no hesitation in the PSD 7.3 when all is in working order. Any hesitation is an indicator of a problem. By design, if all is in order, at throttle tip in, it simply responds. No excuse such as mileage considerations. This = repair bill.

This is my humble stab at the start of a common. Please feel free to chime in with corrections or additions.

Originally Posted by Izzy351

You're in the right place. Pull up a chair and have fun with the best group of folks you'll ever meet on the 'net.