1/2 qt of black oil on the driveway

[jorton]

1. My car has 190,000 miles, low compression and leaks 1 qt/1200 mi from the rear main seal.

2. I don't know yet if the leak came from rear main or the oil filter. Find out tonight when I change the oil.

3. Last night I was decarbonizing with Amsoil Power Foam into the pcv hose when I noticed the oil on the driveway.

Does a pcv open when the vacuum hose is not connected?

 

[Wolfox]

When you disconnect the PCV, the system is no longer under vacuum. This will cause oil to leak from areas where the seals were sucking in air from the vacuum when the oil pooled up behind them. It is quite possible the leak's coming from a valve cover or another area of the engine where a closed vacuum system kept the oil from bleeding out.

 

[jorton]

Drove the car to work 50 miles round trip today, so it's ok. Using the cruise control the car used to down shift when driving over tall overpasses. It didn't have to do that today, going or coming back

For future reference, where do I spray in the foam next time?

 

[mdocod]

seems like pcv is a good place to do it- might be easier to do it into the brake booster line however. just remember to put it back on !!!!