I'm pretty sure what's wrong massive blowby loose 1.5 quarts in 20 miles out of breather tube just started about 2 weeks ago 250000 miles on a 98.5 3500 truck was setting for about 4 years runs really good changed all fluids and oil when I got it just checking if it might be something else other than a done engine any thoughts, thanks

 

Does you HVAC work like it should? You maybe have an issue where the vacuum pump is pressurizing the crank case and blowing it out the tube.

 

HVAC seems to work well,so if putting a new pump on might be worth a shot once in a while the A/C will not let any air out but that only happened once a while back. thanks

 

I would check for vacuum leak before rebuilding or replacing the pump. What happens is it looses vacuum and starts to pressurize the crank case and spew oil out of the over flow tube.

To test for blow by do the tea kettle test. Unscrew the oil cap and place it on the oil fill hole. If it blows it out you have excessive blow by.

 

will do thanks ,I think it might be blow by because there is oil around the fill cap also but that may be pressure if the pump is bad, do you know what the vacume pressure should off hand. Thanks Lee

 

You want 20 inches hg. But if you still have cruise and vents it's not your pump.

 

22 inchs engines done

 

Dang that sucks. Good luck on rebuild.