anyone have leaks with synthetic oil, then switch?

[ravenp]

I've got a 97 RS, and recently after having my plugs changed(about 3 wks after), i've started noticing an oil drip. It's dripping off the converter bellhousing, but I haven't been able to trace the source.

The weird part is that it drips for a night, and then dries up. If I take the car out for a short easy drive... nothing. Then if i take it out and drive it hard, next morning i have a puddle again.

It was suggested to me that it's possible my car would not leak if I went back to natural oil, because synthetic is so much thinner, it has found some holes.

This isnt' to say there might not be another problem, just that it's POSSIBLE that by switching back to regular oil, the leaks might go away?

Any thoughts?

[zippy]

YES! I have had the same problem! At 18k miles (when I bought the car), I switched to Mobil 1. At about 50k, I noticed little drops of oil under the car where I park. At my next oil change (which I do myself), I noticed oil on the undercarriage from about the tranny back - but when I checked the dipstick, I never was down much at all (about 1 quart every 2-3k miles - not too bad). Then someone made the suggestion that the synth oil might be too thin and finding the "holes" in the gaskets. So, at my last oil change, (approx. 80k), I switched to Valvoline semi-synthetic and guess what... No more little puddle drops under the car! And I was told here on this board and in person by my car people friends that switching would cause no harm. So, guess what, I stopped my leak(s) and am saving money in the process ($14. a case for the semi vs. $25. a case for the Mobil 1). HA, who's better'n me? The only prob is that I have to change my oil a bit more frequently (3k vs. 5k).

The Zipster

[CARdiac]

Synthetics are thin compared to "organics" I was running synth until about 90K when I noticed my valve covers, rear seal, oil pan gasket and a few other unidentified things leaking.

Before replacing everygasket on the car I switched to Maxlife (came out at the same time as the leaks....conspiracy?) after a couple of oil changes the leaks diminished adn now I have a very small one, one tiny drop.

[ravenp]

I guess it would be a lot cheaper to switch back to regular oil instead of fixing all those gaskets and stuff, but I suppose I probably should still get them fixed eventually [img]smile.gif[/img]

Did either of you notice a performance difference going back to regular?

I've had the car 3 years and have run synthetic from day one. Not sure what the previous owner did.

[CARdiac]

No difference in performance.

[Viper]

Well this is all true the synthetics will leak on some cars. I had the same problem but I definately wanted to use the syns so I went to 10-40 and no more drips on my 95.

Viper

[Fear_Factor]

I run synthetic, but I dont use mobil 1. I get amsoil its the best. My car is a 95 with 72k and I dont have a problem with leaks. There is no performance advantage. Synthetic protects better and is 10 times better in the winter, especially on cold starts.

[ravenp]

This morning I woke up to a Check Engine light :(

I guess I can't put this off any longer... gonna have to take her in for some diagnostics.