Hi all
My dad has had some car trouble lately(his van died). So being the good son I lent him my tow vehicle (84 chevy 6.2 Deisel)and told him to keep it for however long he needed. Well He has had it now for 3 years!!! Not really a problem I use it whenever I need. UNTIL TODAY!!!! I went to haul some materials, and this thing is smoking like I was fogging for mosquitos whenever I lean into the throttle!! It used to smoke on start up and thats it. It is blowing Oil smoke. I am sure of that and It falls flat in its face on the highway if I mash the pedal down or even going up a grade. I had the injection pump rebuilt right after I "gave" it to him. His comment is that he didn't notice anything.(he never does,thats why he has car trouble in the first place I guess).I checked all the fluids.(OK) and he has been changing the oil regularly. Someone please tell me its something simple!!! I am just freaking, the weather is finally breaking, the Combat Rat is finally running , NOW THIS! Thanks for any help

Milan

Could you have a bad batch of diesel fuel? Running #1 instead of #2 or vice versa ( I forget, it's been awhile), moisture, leaking head gasket.

I had a VW rabbit diesel (yes, I admit it) hand me down. When I got over 75, it would suck oil out from the breather hose that ran to the crankcase and it would take off like you had a turbo on it. So I think oil comsumption would increase the power (diesel is a fuel oil basically). I sure some other people with more expereience will chime in. Godd luck. - John

Are you sure it's oil smoke? Is it light blue, or is it more white? If it's white, you've got a cylinder or two not firing, which would become evindent under load, but it will usually idle just fine. One handy tool I use to diagnose a diesel quick is a Raytek laser thermometer. Look at each exhaust port on the manifold before it gets to the log. Any deviation over 5-10 degrees from the rest is usually an indication of a bad injector, or worse, a broken or chipped exhaust valve. A diesel that's just worn out usually won't "feel" any different in power, it just won't make much. If it doesn't feel and sound clean, it's probably more of a mechanical or tuneup problem than a wear problem. FWIW, I've pulled diesels that were running, but had valves stuck through the piston crowns. They just didn't feel "quite right".

I hate to be the bearer of bad news but that 6.2 was not Chevys finest hour. They don't last forever. If it were mine I'd stick a 350 gas engine in it, thats what we did our last one.--No smog checks-- :D

I'm a diesel mechanic and what you describe to me is a bad turbo. It might be bypassing oil and burning it. That would also cause it to be "Flat" on the highway and when you step on it. Take the side off that goes to the intake and look for oil and try to move it up and down looking play in the shaft.It could be other things but from what you have said that's what it sounds like.

Hi again and thanks for the replies. Bad rat it is a 6.2L it's not turbo. I thought only the 6.5L were turbo. I tried both tanks: same. I will pick up a laser thermometer today and see what I find. I WAS sure it was oil smoke but I MAY be mistaken. It was more of a whiter color. It Didn't have that sweet antifreeze smell to it so I dismissed coolant. If it is a cylinder out could it be a glow plug or an injector most likely? Thanks

Milan

I don't know if the 6.2 has liners or not but if it does the seals on the liner could be bad and bypassing water. There are so many possabilities.The injectors need to be pulled and a compression check done.

If I can isolate a specific cylinder with a temp probe what PSI would I expect to see with a compression gauge? or should I just try and swap out an injector?

Milan

You will need to compair the reading with the others cylnders. Also you should use a compresion gauge for a diesel engine (more compression).