I am the 2nd owner of this car and was wondering if switching to synthetic oil after 100,000 miles would hurt (I've heard it can leak). the previous owner changed the oil on time every time but used dino oil, should I stick with that (I have 109,000 miles) because it seems to have worked so far, or should I go synthetic?

 

If there currently is an oil leak... synthetic will probably make it a little worse. Other than that, I see no problem.

 

You would be fine if you switched to synthetic, the switch will not cause any leaks that were not there before.

 

All synthetic is going to do is clean up the engine, which can sometimes uncover an existing leak that was plugged with varnish or dirt.

But if he changed the oil at proper intervals, chances are you're gonna be OK with that.

I've changed many motors over at 100k+ and never had a problem beyond maybe a bit of spotting on the driveway under one car. Fortunately, I don't care about a spotty driveway.

 

I switched to synthetic at 150,000 miles, no leaks at all. Depends on the engine. If it leaks switch back, its not as big of a deal as some people make it out to be. More than likely it will uncover an intake leak that was very minor before, but you should just fix that stuff anyway

 

I switched to synthetic when I had 90k miles on the engine. It had never leaked before, but as soon as I changed to synthetic, it started to leak from the rear main seal. I changed the seal and it dosn't leak anymore!!

 

And what made you feel better? Finding out that you had a leak and fixing it the right way and allowing you to run synthetic from that point on? Or do you regret ever doing it in the first place? Just remember the leak was already there, just hadn't surfaced yet