Smoky 1995

Our 1995 Diesel Suburban spits outblack smoke at start up and white smoke while idling. The smoke disappears as soon as it gets up to about 35 for a few seconds. The mechanic tells me to replace the engine!

You need to get a new mechanic Try a GM Tech .
I would bet you dont need a new engine.
Black smoke on start up could be as simple as a aircleaner needs changed or bad glow plugs. and white smoke at idle on a cold engine is at lot of times normal

You need to get a new mechanic Try a GM Tech .
I would bet you dont need a new engine.
Black smoke on start up could be as simple as a aircleaner needs changed or bad glow plugs. and white smoke at idle on a cold engine is at lot of times normal

I hope I don't need a new engine. I have replaced the aircleaner and glow plugs and a lot of other things. It smokes even when the engine is hot. I even tried a fuel additive that seemed to help a little. The mechanic thought it sounded like fluid was leaking into the engine. Cracked head or maybe the head gasket.

It sounds like you may have more then 1 problem.

Upon start-up, does it run rough? Maybe Glow Plug controller is not warmings plugs enough when longer glow time is needed. Maybe coolant sensor to blame? Maybe injectors need replacement?

You said smoke clears after 35. Then you say it smokes even when hot?

Be more specific...

Are you losing coolant?

Is your turbo working? Can you hear it?

It does run rough upon start up and it is hard to start. I replaced the starter, checked the glow plugs, and the injectors. I have not checked the coolant sensor and the "check fluids" light comes on periodically, but when I check the fluids they truly are low. I replaced the radiator and had a mechanic check for leaks. The second mechanic thinks I have a leak into the engine through a cracked head or head gasket.
The smoking is really odd. It smokes when cold or hot while idling, but clears while driving a short distance at about 35. It usually sets into smoking immediately at stop after any driving distance.
I am pretty sure the turbo works. How do I test it?

You need to find out if your losing antifreeze.

If you have a cracked head, block, or a bad head gasket, that would explain your white smoke.

When you start-up a cold engine, do you get pressure immediately in the upper hose?

You will need a boost gauge to test your turbo. Do you hear it 'Whistle' at all?

Thanks for your help. I will try your suggestions and post the results.

EEEEEks. This sounds familair with my own 1995. White smoke = blown head gasket. Believed to be sticky thermostate, which caused the coolant is low light to come on and off, finally sticking causing it to over heat. $3800 canadian for new heads and all. Just got it out of the shop and within two miles could hear there is a turbo problem that wasnt there before we took her in. Returning tomorrow to see what they are gonna do about it.