oil coming out and blowing out oil stick

[cary thomas]

I have a Bronco II, that has 40,000 miles on a rebuilt engine. On fast idle the egine will not blow out oil. I can run a rubber hose from the oil spout and get a quart of oil in a bucked driving 55 mph.

A mechanic told me compression on number 1 is low. The motor is not skipping or smoking.

Pleas help.

Danny

 

[BLADE262US]

Whats probably happening is that at road speed that cylinder that is low on compression is not sealing up anymore and allowing the comressed air to slip past the rings and pressurize the crank case which is forcing the oil out the dipstick tube and any other place it can escape . Only way to fix this is to tear the motor down and see if theres a broken ring or piston in that cylinder . /emoticons/[email protected] 2x" width="20" height="20" />

 

[indoz]

Cary, try this old trick to confirm bypass on your No.1 piston, do a compression test on it, record result, then with an oilcan squirt some oil in the cylinder and do another compression test, if the result with oil in is higher then you have definite bypass, if result is the same you have valve problem.

Good luck, Henk from Oz

 

[ofthesouth05]

friend of mine had same problem on a GMC. Every time he cranked it *ping*, the dipstick shot up and hit the hood. Come to find out he had a hole in a piston, could drop a welding rod through it and hear it hit the oil pan. Try to pull your spark plugs and (brace yourself) :-& stick a close hanger in the cylinder to fell along the top of your piston for any cracks or holes. It's a possibility