Hello,

i recently took took my car out and finally got on it for time this season. Car was “fully built” about year and a half ago, and I’ve only really token it out a handful of times after that. Today after maybe 20 minutes of driving it and doing three 2nd gear pools, I noticed a good amount of oil under the car in the garage. There seems to be a spray of oil around the dipstick and all the oil on the bottom of the car is around that side of the car.

My my thought is, while under boost the dipstick lift up, causing oil to come out. Is this plausible or would that not cause a lot of oil to drip on my garage ? I got home about 3 minutes after it was last under full boost.

 

as you know, your dipstick is housed in a tube leading directly into the oilpan. dipsticks have rubber seals to retain them in the tube and the rubber is... 28 years old, so often it has lost its elasticity and ability to hold the dipstick in position. i remember going through about ten dipsticks that i had collected over the years and finding one that was "good" in terms of elasticity. (not a bad item to replace, call Ray)




of course all motors generate some amount of crankcase pressure and that's why most boosted motors are equipped with a one way valve to relieve the pressure. many modded cars don't run the valve but run a vented catch tank. it is possible that your one way valve is not working leaving all pressure to get relieved through the dipstick tube. check to see if you have a one way valve leading into your UIM and that it works.

if no one way valve do you have a catch tank?

as mentioned, all motors create some crankcase pressure, the key is the degree. remove the dipstick, start the motor, rev it a bit and observe the flow from your dipstick tube. there shouldn't be much. i did not retain the one way valve but run a catch tank. all catch tanks should have a breather, a drain and a sight tube. note my sight tube is bone dry after 3 years. this should generally be the case. if you have a functioning vent (one way valve to UIM or catch tank) you should not have significant crankcase pressure. more than normal pressure generally relates to oil seal condition.

 

Thank you for your help. I believe it had to do with the crank pressure. No leaks at idle or when at 3k rpm. Haven’t had a lot of free time to do more testing but running a catch tank should solve the issue