i have heard that when your car is old and hasnt been run with synthetic oil that changing to something like mobile 1 is bad for it because it is thinner and it will leak out more or somehthing. i have had the car for almost 2 years and have been using valvoline max life with a fram tough gaurd filter and want to get the best out of the ol LG4 while i can because i dont really have to money to put in a 350 (yet). i was wondering if this would be good for the car and would make it last a little longer. it has 130,000 miles and runs well, smokes a little at startup,(new valve seals coming soon) and is basically a solid running car but i want to make it last for as long as i can. any help appreciated.

 

Don't put synthetic oil in that engine. There will surely be sludge built up and deposits on the gaskets that the synthetic will clean off, which will lead to leaks. And if you want to save money, just keep using what you've been using. Don't fix the valve seals if it isn't making you lose a noticable amount of oil between changes, that's just money that could go to the new engine!

When you do get a new engine, I'd advise running mobil 1 with ac delco filters if you can get them--after the engine is broken in with regular oil, of course.

 

I switched My 90 Lumina 3.1 over to mobil 1 a few months ago 15W-50 . I had 136,000 miles. No leaks No nothing.

 

Synthetic doesn't cause leaks, but may make ones there worse. I'd say just stick to what you got, it would be more important to change it every 3k miles than switching.

If you get a new motor down the line, use synthetic.

 

i switched my 35+ year old tractor over to M1 4 years ago with no leakage problems, also never had a problem on any cars or trucks i've switched.

 

That's what I call 100% bad advice.

For the sludge and varnish build-up, use a crankcase flush before changing over to synthetic (AMSOIL makes an excellant product). Or, change the oil and use 1 quart synthetic, balance petroleum; next change use 2 quarts synthetic, balance petroleum; and so on until you're 100% synthetic (change the filter each time, by the way). Synthetic-based lubricants tend to swell seals, so if they aren't cracked, they will become more pliable when exposed to the synthetic.

Continuing to use a petroleum-based oil is not a good way to save money.

Replacing the valve seals in a 130k miles engine that's had petroleum-based oil in it throughout its life is a very good idea. It'll pay for itself in reduced oil consumption (assuming you do the labor yourself and don't charge for your services). You'll be replacing the valve cover gaskets at that time, eliminating another source for leaks. Oh, those factory valve stem seal o-rings tend to crack as they get hard, so no "Max Life" oil with extra plastisizer additives or sythetic-based lubricants will swell them back to life.

Like others, I have switched over several 100k-plus miles vehicles that have had regular maintenance previously with no problems. Mobil 1 has a reputation for higher oil consumption than AMSOIL, so I wouldn't recommend the Mobil 1 without reservation. But, the high-mileage engines I've switched over to AMSOIL have showed decreased oil consumption over time.

 

Sorry, just my opinion. I had a lot of leaks on my 130k engine AFTER switching to mobil 1. And I think I wasted the money I spent on it-I've just got a new 350 now, and all that mobil 1 wasn't free. Sure, it's only a couple hundred dollars in the end, but wouldn't you rather spend that on something you're going to enjoy rather than get rid of?

 

Save your money, to late making the change to Mobil 1 in a older engine. With a brand new engine, fine spend the extra money.
My opinion.

 

Two things:
1) He's not getting a new engine anytime soon.
2) He wants to get the most out of what he has now.

If it's been at all maintained, 130k these days is still reasonable. Mobil 1 may not be the best choice (wouldn't be mine), but it isn't the worst choice.

Continuing to use petroleum oil is, in my opinion, a bad choice, unless the engine needs an oil fill-up more often than a gas fill-up, or the engine is coming out very soon. For people who live in cold climates, synthetic can still be a good choice even under these circumstances.

 

I agree with '57........