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“Breaking News: Classic Car Engine Eaten From The Inside Out.”
Ridiculous? Not at all!
One of the most important, simple, cost effective yet often overlooked maintenance routines certainly is an oil change at regular intervals.
Why is it unloved then?
Simply because it’s not sexy and you don’t notice it from the outside. You’ll never get a compliment from someone saying your car looks much better after you’ve changed your oil.
A trained professional will certainly notice that the engine idles and revs much smoother and pulls better after a fresh oil change, but most people won’t.
So why should you bother?
Why Change the Motor Oil?
To understand why, one should understand what motor oil does inside a classic car engine:
When turned off, the motor oil settles at the lowest point of your engine: the sump. That’s the “bulge” that sticks out from underneath the engine.
From the moment you start your car engine, cold motor oil is pumped from the sump throughout the engine to perform following key tasks:
- Motor oil lubricates all moving (rubbing) parts to minimize wear and optimize efficiency.
- It dissipates heat that is generated by the combustion process and from friction of moving parts. This is crucial to prevent overheating.
- Detergents in the motor oil remove carbon deposits that would otherwise build up and clog your engine. Excessive carbon deposits are bad for engine performance and gas mileage.
- Motor oil neutralizes acids, formed by the combustion process. These acids would otherwise cause rapid oxidation (rust) of engine internals and attack seals and gaskets.
- Even in optimal circumstances an engine’s moving parts grind off small metal particles, caused by friction and wear. The motor oil flushes these toward the oil filter, where the larger particles are filtered out. If they would stay in place or recirculate, they would dramatically increase engine wear.
In order to slow down deterioration of the oil’s properties, motor oil manufacturers add a cocktail of additives too.
How To Do an Oil Change
To protect and preserve your engine, every winter before storage you should change your motor oil.
For the motor oil that is best suited for your classic car, check our post about “Best Motor Oil”
Anyone can do this. Just follow these simple steps:
1. Warm up your engine to operating temperature (preferably drive it for 10 miles).
A cold motor oil drain won’t remove all the settled sludge at the bottom of the sump because it solidifies when cold. It will contaminate your fresh oil once you put it in.
2. Get easy access by getting underneath your sump.
This is essential to not screw this up and most importantly to not injure yourself.
If your classic has high ground clearance like an SUV or pickup, you’re good. You can skip this.
Most classic cars have too little ground clearance and require one of these two solutions:
Drive over an inspection pit. More on this subject in “how to build your own inspection pit”.
Lift your car.
More on this subject in “How to lift your car”.
3. Put a container under the sump drain plug to catch the stream of hot oil that will be pouring out of the drain plug hole when the plug is removed.
The drain plug is situated on the lowest end of the sump, underneath or on the side. When in doubt, consult your car manual.
Any container of about 15 qt / L will do, but a low profile oil drain pan is better for low clearance situations, while an upright oil lift drain works best for full height lift situations or in inspection pits.
Both solutions prevent (hot!) oil spills which can be dangerous and very messy to clean.
These professional solutions are purpose designed with easy emptying solutions for safe removal of dirty oil without spilling or making a mess.
4. Use a spanner to loosen the sump drain plug ½ turn or until hand-loose.
Measure with a digital caliper for the right spanner size or check your car’s manual.
Don’t use open spanners or pliers, they might mess up the plug’s edges (and your knuckles). Be especially careful with copper plugs, which are softer and more prone to damage.
If you screw up the plug’s edges to the point that even a socket spanner or hex can’t get a grip, you will be in a world of pain to get it out… So handle with respect!
5. Now first make sure your oil drain container or portable upright oil drain is stable and in the right position to catch the oil stream.
Once the plug is removed, the oil will stream gravity-fed. It is not under pressure. It will be a massive jet, though. The jet will gradually lose strength once the oil level lowers.
If the plug opening is to the side of the sump, this should be taken into account when placing your container or funnel under the drain plug opening.
The oil jet will squirt horizontally in the beginning, gradually evolving in a vertical stream and then a drip. Don’t get caught by surprise 😉
CAUTION: THE OIL IS HOT!!!
To prevent nasty oil burns we advise using heat and oil resistant gloves!! Wear a face shield or at least eye protection to prevent hot oil splashing in your eyes and face, unless you think oil splatter burn scars in your face and an eyepatch look cool 😉
6. Loosen the plug further by hand until it comes out.
Be patient and let it drain till the last drops. The sludge and nasty stuff is the last to come out.
7. Screw the sump drain plug back in place, do not overtighten.
First check the copper sealing washer on the drain plug or gasket ring (if any / depending) for damage, replace if necessary.
8. Change your spin-on oil filter or oil filter element (depending):
CAUTION: THE OIL IS HOT!!!
To prevent nasty oil burns we advise using heat and oil resistant gloves!!
Wear a face shield or at least eye protection to prevent hot oil splashing in your eyes and face!!
Spin-off oil filter: loosen by hand or with an oil filter wrench, put an old rag or small container underneath to catch the spill.Screw on a fresh spin-off oil filter until hand-tight, do not use tools.
>IMPORTANT: before installing the filter first grease the rubber sealing ring with some motor oil
Oil filter element: loosen the oil filter bowl bolt, the filter housing will come loose, put an old rag or small container underneath to catch the spill. Replace the old filter element with a fresh new one. Reassemble. Put some oil on the rubber oil seal. Tighten the oil filter bowl bolt firmly, do not overtighten.
Please ensure every drop of used motor oil, every oil filter, and every oil container is brought to a collection centre to be disposed of properly.
A single drop of used motor oil can contaminate a million drops of water.
9. Remove the oil filler cap. Fill up with oil, starting with less than the user manual advises. Preferably use high zinc mineral motor oil for better wear protection.
Check for correct oil pressure on engine restart.
Check the oil level with the dipstick after you’ve run the engine stationary for a couple of minutes. The idea is to fill the new oil filter and crevices with fresh oil and to remove air pockets.
With the engine turned off, top up gradually, allowing the oil level to settle before adding some more. Add until the “max” level on the dipstick is reached. DO NOT OVERFILL!! Screw the oil filler cap back on.
10. After 100 miles check for oil leaks around the oil filter and sump drain plug, tighten if necessary and top up if needed.
CONGRATULATIONS! JOB DONE!
Notice how soft your engine runs after an oil change. Very satisfying, isn’t it ? 🙂