What to check when buying???

[jpaitala]

Newbie want's to say hi to everyone...

I'm in a process of buying a diesel truck now. Two options,
1 - 1993 Chevrolet Silverado crew cab dually 6.5TD 4*4(mileage 150 000)
2 - 1997 Chevrolet Suburban 6.5TD 4*4(mileage 180 000).

What to look when I'm going to see these "trucks"? I have no previous experience with diesel engines. "Specific instructions" would be great.

Thanks.

[catmandoo]

93 last year of mechanical inj pump.probably less headaches for you overseas.

[jpaitala]

Anyone with a "check list"???

[Mark Bajus]

depends how much you want to spend! Some options:

Id do a compression check (would have saved me a rebuild!), look for one or two cylinders lower than others.

Cooling system pressure check (checks for head + head gasket leaks)

oil analysis (checks for internal wear metals, can also check for engine coolant in oil)

[slagona]

Since no one has given you a list yet, here's what I would do if I were looking at a diesel truck:

1) set up a time to see it - INSIST that the truck be completely cold at this time (sitting at least 3-4 hours - preferably more). A low compression engine will start harder when cold. Many sellers will start it and warm it up just before you arrive so that it seems to start easier.

2) check all fluid levels - make sure you open the radiator overflow - they tend to get tinted with age which makes it appear as if they have fluid in the resevoir. Note the condition of the oil, transmission, and power steering fluid. The oil should be black. Even after a recent change, it will turn black quickly. Transmission fluid should be red with no burnt smell.

3) Check the fuel filter. Bring a section of hose with you (3/8" ID???? - I can never remember) to slip over the air bleeder on the fuel filter. Open the bleeder, and also open the drain (located near the thermostat housing) Blow into the hose you've attached to force the fuel out the drain (make sure you collect the diesel fuel from the drain hose). Remove the screw on ring that holds the filter in and pull the filter up and out. Check the condition of the filter and bottom of the bowl. A new filter is white. A normal filter is a brownish-black. A dark black filter could be a sign of bacteria in the fuel. Check the bottom of the filter bowl for junk. Could have metal, dirt, slime, .....

4) Now you can test the lift pump since you've emptied the fuel filter of fuel. On the '97 you should be able to remove the fuel pump relay and jump the pins (looking at the relay from the drivers wheel well, I believe they are the bottom left and top right pins - again, I'm going from memory - over a year ago since I've done this - I can't remember what I did yesterday..... Do a search to see if you can verify the correct pins). For the '93, there are a few ways to force the pump on - again, search to see if they still exists on this forum (putting the gear selector in Netrual ans turning the key to the start position sort of thing). Close the drain valve when doing this - continue until all the air is out of the tub you've inserted in the air bleed valve.

5) Check the condition of the tires - unusual wear indicates some problems.

6) Bring some sockets and wrenches with you. Remove the skid plate (Plastic under center of front bumper). Check for leaks on the oil cooler lines and oil pan with this skid plate off.

7) You can check the glow plugs with a 20 amp tester. Unplug a glow plug, run the tester from positive battery to the glow plug. It should run up to 14-15 amps in serveral seconds. Don't keep it hooked up more than 4-5 seconds. Any plugs not showing amperage above 10-11 amps are suspect - test all glow plugs. Remove a few of the glow plugs on the driver's side to see what kind of condition they are in (of course this is without the engine running). I would test the glow plugs before starting the engine to see if they are all working.

8) Now, you are ready to start it up. Extended cranking times are a sign of low compression, bad glow plugs, ..... Check for smoke from the tail pipe when starting. Some white smoke is normal on a colder day - but it should go away quickly and the engine should run smooth. If smoke persists of the engine runs rough - there may be a glow plug problem. White smoke can also be a sign of air in the fuel system (also causing extended crank times).

9) remove the oil dip stick with the engine running (or the oil fill cap). There should be no smoke or vapor coming from the opening. If there is, it is a sign of excessive blow-by. Which means a rebuild is in the future of this engine.

10) The engine should revs should cut back to 600-700rpms at idle after a short time (longer on cold days). Let the engine fully warm up (185 on the engine temp guage). It should eventually run smooth with no smoke.

11) if you have a compression tester for diesels - check the compression after it has fully warmed up - there is a recent thread on this subject.

12) Check for leaks while idling. Bring a flashlight - check the valley, sides, and bottom of engine. Check the oil filter area for leaks - also the oil cooler lines connect to the block above the oil filter.

13) Drive it. Test EVERY feature of the vehicle. Windows, doors, A/C, heat, 4wd High and Low, ..... Everything.

14) Find out everything you can from the owner - history of repairs, pump replacements, ......

That should give you a start - off the top of my head. Somewhere around I have a list, but to be able to find it.........

Hopefully others will correct the above and fill in some gaps......

[jpaitala]

This the kind of list I was hoping for. Thank you very very much... That check list is going to be very helpful when checking those trucks.
Let's see if I can go to see those trucks this weekend, not sure because they are quite far(450km) away from me. These trucks are not as easy to find here in Finland.

[lineman]

jpaitala,Be sure to ask if the injector pump and injectors have been changed out or not.With that many miles both trucks are due for both to be done soon.(Make sure that if the 97 pump has been changed, that it has the green tag on the pump.)Also make sure that the trucks are priced cheaper if these two things have not been done, because these are costly repairs