weird blowby question

[ccoxva]

Ok i have an 89 na. More blowby than any mack engine i've ever seen, but its only from the valve cover. Zero b b from dipstick tube??? Engine starts good in cold, doesn't use any oil between changes??Whats the deal.

[zukgod1]

Sounds normal to me.

check the blow-by while your hitting the throttle.

IE: put your had over the oil fill cap and with the other hand hit the lever on the ip. I bet the blow-by all but goes away. 

[Mark(The Miser)UK]

Ok i have an 89 na. More blowby than any mack engine i've ever seen, but its only from the valve cover. Zero b b from dipstick tube??? Engine starts good in cold, doesn't use any oil between changes??Whats the deal.

Oil tube is long and narrow and stuffed with oil dipstick. When testing by reving the engine, squeeze vent tube to see real blowby