What to look for in an early diesel truck

[ScottH]

I may be going to check out an 82 GMC k1500 in the near future and could use some advise on what to look for regarding the engine. I've never owned a diesel before so any advise would be of great help. I do know that it was the 1st year for the 6.2. The truck has about 120k on it.

Any info is appreciated.

Thanks
Scott

[ol yellow 72]

take my advise i learned this one the hard way, find ur self a good diesel person and take them with you when you look, i ran upon a 86 cucv diesel that only had 40,000 on it for $800 i thought WOW deal of the year here, me being a total idiot on diesels, jumped on this deal, it started and ran fine, so i was a happy camper. Getting it home the next morning was cold, crank, crank, crank, crank, and no start, turns out the glow plugs were swelled to the point it had to have heads removed. so at the least remove one glow plug ad check it. mine need over $1000 worth of work. so my advise is study up really good, or get a mechanic to go with u, with that being said, as bad as mine was i loved the power and the fuel economy with mine, and it was a low buck diesel. expect around 150 h.p., and i got 18 mpg in my blazer

[hatzie]

Originally Posted by ol yellow 72

take my advise i learned this one the hard way, find ur self a good diesel person and take them with you when you look, i ran upon a 86 cucv diesel that only had 40,000 on it for $800 i thought WOW deal of the year here, me being a total idiot on diesels, jumped on this deal, it started and ran fine, so i was a happy camper. Getting it home the next morning was cold, crank, crank, crank, crank, and no start, turns out the glow plugs were swelled to the point it had to have heads removed. so at the least remove one glow plug ad check it. mine need over $1000 worth of work. so my advise is study up really good, or get a mechanic to go with u, with that being said, as bad as mine was i loved the power and the fuel economy with mine, and it was a low buck diesel. expect around 150 h.p., and i got 18 mpg in my blazer

The 6.2 is a decent engine when cared for.

The first thing to look at is the tailpipe when you first start the truck.
In warm weather Grey-White smoke smelling heavily of fuel that clears shortly is OK but may indicate one or two weak glowplugs or a slow cranking starter. In cold weather it may drop sharply then taper off as the engine warms up.
Grey-White smoke that continues after the engine has warmed up is an indicator of fuel system problems (air in the fuel, weak injectors, or injection pump problems) or low compression from a worn engine or blown headgasket.

Black smoke on anything besides foot to the floor acceleration is overfueling from an air restriction, pump timing not set properly, or worn injection system components.

The early 6.2 trucks didn't have a proper water separator. I usually replace the GM 6.2 Box Filter units with a Racor 645 spin on filter/water separator element if it hasn't been done already.

Put your hand on the glowplug relay to make sure it's switching when the ignition is turned on with a cold engine. The Early glowplug controllers were supposedly problem children. Switching out to a later one piece controller is very easy.

You can check each glowplug individualy with a multimeter. The 6.2 6.5 are pre-chamber engines so I've just pulled injectors on the offending cylinder to break off and extract the pieces of swelled AC11G glowplugs. Needle nose pliers for the big chunks and a vacuum for the small pieces. Good modern Dual Coil Positive Temperature Coefficient AC60G glowplugs will not swell when they fail.

If the engine is warm when you arrive they're probably hiding a problem. I'd be seriously tempted to walk away...

[ScottH]

Thanks guys, really appreciate the info.