GM-GMC: 89 gmc 5.7 tbi, valve spring compressor, dollar range

Question
Truck blows a cloud of blue smoke at start up after sitting for a while. Cloud disappears quickly, truck runs good. If only shut off briefly...no smoke at start up.

Answer
cory it is nothing to worry about it is the valve guide seals these are made of rubber and over a period of time they swell when the vehicle is warm or driven a little more regularly this becomes less noticeable if this bothers you can replace them fairly easybut you would need a few speacialty tools for instance a valve spring compressor and a fittin g that fits into the spark plug hole and hooks up to a air compressor to keep the valve from falling on top of the piston new seals are in the $30 to$50 dollar range.