I recently switch from quaker state 10w30 conventional to quaker state full synthetic and I'm not happy with the results.

My car is a daily driver, not a kept car.
The engine has less than 20k miles on it.

I added a half bottle of lucas with the synthetic oil, as I do with all my oil changes.

The first week, I have noticed no leaks.
The temperature outside has dropped quite a bit since a week ago,
and now I have a slow leak from the main seal!!

A buddy tells me the seals could be shrinking due to the cold.

I noticed the leak today at lunch when I went to gander at my car.

I drove it from home to work which is less than 2 miles and it does not get up to operating temperature during this drive.

I go to school every day and that's 20 miles round trip.

It looks like the leak is coming from the front main seal behind the harmonic balancer.

Any ideas?

I did just have the harmonic balancer replaced to a street performance one. But that was like a month that ago and never noticed any leaks.

​​​​​​​Any idea??

 

Don't blame the oil. Synthetic will break up and dissolve sludge that conventional oil leaves behind. Many of times, that sludge was preventing a leak that was there the whole time from showing. At this point, the only way to remedy it is to replace the seal.

 

You should have replaced the seal when you replaced the harmonic dampener anyway. Sometimes, even an on and off with the same dampener can be enough to aggravate the seal and cause a leak. I wouldn't go blaming the oil.

 

Never put an additive in a synthetic. They can cause a chemical reaction. The cleanest engines I have ever pulled a part are the synthetic only engines.