Oil Leak

[Rudedog]

I have a 1975 with a 2.7. The mileage is unknown, but it has a fresh top end. I started using Mobile 1 and the leak started shortly after. Could the different oil be the cause? The leak is either the Oil Pressure sender or the Oil Cooler.

[AFJuvat]

IMHO (others will have differing opinions)

You probably had a small leak in that area to begin with. After switching to Mobil 1 - it disolved the sludge and made the leak worse.

Check the oil pressure sender, and the thermostat O-ring Also, check the condition of the breather hose - they harden with time and seep oil.

AFJuvat

[aigel]

Go back to dino immediately. AFJ is correct, it's the synthetic oil causing it. Well, the leak is there too, but unless you want to drop the engine for fixing it (you'd have to do that with CIS, I'd assume), go back to dino. It may stop.

George

[kach22i]

I had to switch back to Dino. I am going to change it again in another 500-1000 miles just to make sure all the evil synthetic is out of it's system. I mean it has 11 quarts of new Castrol 20w50 in it, but capacity is 13.7 quarts................somewhere 2.7 quarts of synthetic is eating away at something.

1977, 2.7L 94,000 miles.