Car has been sitting for almost 2 years.

[Nicasio]

So my cousin’s 1990 Mustang 5.0 has been sitting in the garage for almost two years. He put it away with race gas in the tank so it wouldn’t go bad fast he says. So now he’s buying a new battery and will do an oil change. I know everyone likes to change their oil out with a warm engine. Should he just top off the oil and try to start/warm it up first before changing out the old oil or just dump it out cold and fire it up with the fresh oil?

 

[atikovi]

It's 2 year old oil. Changing it 30 minutes before or after starting wont make a difference but the hot oil will drain more completely.

 

[Leo99]

I'd dump it cold. Who knows what has settled to the bottom of the pan. I'd rather drain that out than resuspend it.

 

[JeffKeryk]

I would put in fresh oil, check antifreeze and fire that bad boy up!

 

[chainblu]

If it was mine, I would start it as-is. I wouldn't top it off unless the oil wasn't showing on the stick. Let it heat up, then change it. Two years in a garage is easy time.

 

[Deleted member 89374]

I'd dump it cold. Who knows what has settled to the bottom of the pan. I'd rather drain that out than resuspend it.

+1

 

[JHZR2]

Nothing wrong with starting up on the “old” oil. Oil in the sump for two years has absolutely nothing wrong with it. In many places two year OCIs are a normal thing. It’s not like the engine has been in hard use.

If you want things to speculate on and be worried about, I’d be much more concerned with rodents in the air filter and exhaust and hvac system then anything related to the oil. And I keep a large collection of cars with many that often sit for extended periods. Zero issues.

If anything, turn the engine over by hand, or even go as far as to remove fuel and pull the plugs and spin it a few times… anything more is just unnecessary.

 

[compratio10_5]

I would start it and drive it for a while before changing the oil. Here is why. The oil pump, filter and lubrication galleys should still be filled with oil if the anti-drain back valve in the filter is functioning. This will allow near instantaneous flow of oil onto engine wear surfaces during the extended cranking before the engine starts. During the start, the moving parts will wipe the wear surfaces and any corrosion products will be washed into the oil sump. After a good long drive, when the engine has reached thermal equilibrium and wear surfaces have been restored, then the hot contaminated oil can be drained and the turbulent flow will remove most of the contamination. Then immediately starting up after the oil change , with new oil and filter and a warm engine, will occur on freshly lubed surfaces still coated with oil and instantaneous oil flow is not as critical as on the initial cold startup.

 

[hawkdriver]

If it were mine and been sitting for 2 years, I'd want to prime the system before starting and then change the oil after it was warm.

 

[Lubener]

Two year old oil is not a big deal. I would get the engine running and then change the oil and filter after a good warm up. The warm oil while draining will carry more contaminants out the drain hole which are in suspension more easily. A regular oil change schedule can then be followed thereafter.

 

[Lubener]

If it were mine and been sitting for 2 years, I'd want to prime the system before starting and then change the oil after it was warm.

On his Ford, I believe by holding the gas pedal to the floor while cranking will shut off the drive to the fuel injectors. Then cranking the engine will prime the system. I do this on my 87 after long storage.Others please correct me if I am wrong.

 

[RooflessVW]

I'd dump it cold. Who knows what has settled to the bottom of the pan. I'd rather drain that out than resuspend it.

If it has settled, it won't drain out.

 

[RooflessVW]

Pop a battery in it, drive it around the block, rip some sick donuts, and then change the oil if it makes you feel better.

 

[DriveHard]

I'd dump it cold. Who knows what has settled to the bottom of the pan. I'd rather drain that out than resuspend it.

I'd put a pan heater on it, or a traditional IR heater under the pan for a bit to get it good and warm before draining to get as much gunk as possible out.

 

[Barkleymut]

Pop a battery in it, drive it around the block, rip some sick donuts, and then change the oil if it makes you feel better.

Make sure and have Welcome to the Jungle blasting on the stereo.

Personally I wouldn't do anything except start it up and drive it. The oil in my F150 has around 2k miles on it over the past 3 years and I'm not even a little concerned that it doesn't lubricate/protect my engine.

 

[RooflessVW]

Make sure and have Welcome to the Jungle blasting on the stereo.

You gonna diiiiiiiiee

 

[Cujet]

Don't change the oil first. Start it on the old oil. An empty oil filter and drained oil passages just prolongs the time the engine takes to get pressure. 2 year old oil will be just fine. After all it was in the ground for 4.8 billion years.

 

[HangFire]

While I'm in the "old oil is fine" (for a little while) camp, the gotcha could be a slight coolant leak that has had time to pool. If so, the water based coolant will go DOWN to the bottom of the sump, at least, most of it will. Of course, that might mean a bigger problem exists (probably a bad head gasket), but that one problem could be turned into a bigger problem on startup.

If you want to be cautious, I would try this. Pull the plug and replace, drop about a quart of oil. If it looks like oil, put it back or put a fresh quart in and start it. If it looks like coolant or milkshake, drop it all and change the filter, too.

 

[eljefino]

If it misfires on old gas (or for a yet-to-be-discovered reason) it will degrade the new oil.

Plus, you might lose the oil pump's prime doing a change before starting it up.

Old oil is not acidic nor abrasive to engines until well past the normal OCI. If the guy was thoughtful enough to put race gas in it he's thoughtful enough to maintain his oil.

tl;dr run what's in there until you get it running right. Drive it around the block, scrape the rust off the brakes, make sure there aren't acorns in the air filter.