Hi all. New to this site and new to Cadillacs. I just bought a '99 Seville with a new '04 motor. Pleased with the power but concerned with the supposed oil leakage problems. Just replaced the oil and added 5 qts of 10w-30 Castrol GTX and 2.5 qts of 10w-30 Mobil 1. I've used Mobil 1 in the most recent cars I've owned and would like to try it exclusively on my next oil change. The car had 11,000 miles on the new engine when I bought it, it was using Mobil 5000. I'd be interested to hear any suggestions anyone might have about going to Mobil 1. Thanks in advance.

 

If its a GM engine from 2004 it should have the updated seals and gaskets.
We don't see very many oil leaks anymore except for the old ones that were never fixed.

Mobil one is the factory fill on 85% of the new Caddy lineup. We use it every day and it works just fine.
If you had a leak or oil consumption issue than the synthetic could make it seem worse.

Some people swear by synthetics while others feel its a waste as long as you stick to regular service intervals.
We see so little internal engine wear nowadays its tough to justify the expense, however i pay the premium to use it.
Just piece of mind that you are the doing the best you can for your equipment.
May help the resale if you prove your commitment to top notch maintenance.

 

Thanks for the quick response. I'll see if this engine uses oil in the next 5,000 - 7,000 miles and decide if I'll go with the Mobil 1. BTW, what's a good Seville maintenance manual to buy for general maintenance, I see the chassis needs to be lubed in the owners manual but it doesn't explain where or with what. Your advice is very appreciated.

 

go to a dealership to get it lubed and if not Jiffy Lube they have all the stuff youll need. Congrats on the new car i sell cadillacs and i am driving an eldo.