Unwelded used Head source/Mechanic/SanDiego Area?

[6.2Frank]

'83 6.2 Left exhaust issues volumes of whitish smoke.
100,000 on rebuild. Head may have been welded.

Any guesses on odds re. head or gasket as cause?

Unwelded used Head availability & source/& 6.2 Mechanic/SanDiego Area?

What range of prices are fair?
[Yesterday? : ]


Thanks

[TimK]

Frank,

Tons of white smoke from only one bank definetly sounds like a loss of compression on at least one of the cylinders. Is it possible for a head or head gasket to cause this problem? Yes but it could also be caused by a bad injector, broken piston rings or a cracked pistion. If you are losing compression, that compress air is going somewhere. Bad Rings,cracked pistons and sometimes a head gasket will dump the air into the crankcase and therefore you should notice a lot more blow by then normal. A bad head gasket or cracked head could put the compressed air into the cooling system, another cylinder or to the outside air.

With the truck idling, individually loosen the fuel pipe to the injector. If it stops smoking, then that's the cylinder.

TimK

[6.2Frank]

Thanks, Tim.
Mostly white smoke, I thought, would mean water in exhaust. ???

[TimK]

Frank,

Yes and no. If it's actually steam, then it's water or coolant. If you are running anti-freeze then the exhaust would probably have a sweet smell as the coolant is vaporized. This could be caused by a cracked head, block or head gasket. But for a diesel, white smoke is also an indication of unburnt fuel. The exhaust would have a pungent smell of diesel fuel. This is similiar to one of the large over the road type diesel truck when they start up first thing in the morning and you see a huge plume of white smoke coming out the exhaust stacks. With the engine cold it doesn't create enought heat to burn all of the fuel. Our 6.2L and 6.5L diesel may do the same thing when they are cold. The colder the engine the worse it is and the lower the compression the worse it is. But as soon as the engine warms up a little it should go away. I have seen engines with badly worn rings smoke like hell at idle but once the RPM's are increased the white smoke goes away. This is because at low RPM's the cylinders are losing compression pass the rings and the lower compression results in not enought heat to burn all the fuel. If the timing is off, it will also cause a lot of white smoke to come out the exhaust but this would basically affect all the cylinders to the same amount and not just show up in one bank of cylinders.

Something else to consider, if you are seeing a lot of white smoke, and you think it is coolant, then you should be noticing a lot of coolant routinely disappearing from the radiator.

TimK

[6.2Frank]

Thanks a million! Guess I've got possibilities to rule out before pulling head.

When loosening lines to injectors one at a x, does that mean loosening a little will admit air & stop fuel flow, or am I looking for lots of diesel running outside w/each instead of inside?

[DmaxMaverick]

By loosening the injector connectors, you are stopping the fuel delivery at that cylinder. The fuel "leaks" out, and prevents the fuel pressure from popping that injector.

If you have an injector that is over fueling, or leaking internally, loosing it will stop that occurance. Loosening one at a time will allow you to hear the difference of each cylinder. Each good firing cylinder should cause a noticeable miss. If you loosen one and their is no change, that is probably the "missing" cylinder.

You should also check that your return lines are all free of obstruction. If you have a blocked line, the return fuel has no where to go, and usually ends up getting dumped into a cylinder off-time, causing a bunch of white smoke.

[6.2Frank]

Thank you, guys, for taking the x to explain patiently what must seem obvious to you, to one who is learning diesel.