i got a nice oil leak at the back of the engine. this started when i put mobil 1 full synthetic. anybody know where a common place this could be coming from

 

Brody,

1. Distributor base gasket;

2. Rear intake end gasket;

3. Crankshaft rear main seal;

4. Lifter gallery plugs;

5. Camshaft bore plug;

6. Oil pan gasket;

7. Oil pressure sensor;

8. Oil filter or adapter;

9. Auxilliary oil pressure switch;

10. Oil cooler lines (if equipped).

The beauty of changing to full synthetic is that it cleans up all the sludge and varnish in the engine, and protects and lubricates better than mineral oils ever could. The danger is that since it cleans so well, it also removes varnish and sludge that may have been sealing your engine. If you have a slight leak that was gathering oil, that oil may have gathered atmospheric dust and burned into a sludge that sealed the leak. The synthetic will easily clean all that away.

Wash the engine thoroughly from top to bottom, then start watching for the source of the leak. If you're lucky, it's just a pan gasket or distributor gasket. Lines are easy to repair, and an oil filter adapter is easy to repair. Either of the switches would be fairly easy to seal, but a failed intake gasket or rear main seal are going to require a lot more work. Good luck.

BTW - If you ever change to silicate-free coolant (Dex-Cool) it will find the smallest leaks and wick through as well. Just thought I'd mention that to prepare you.

 

thanks