Oil Spots, Primer and Why Sealer Peels Where You Park

September 14, 2026

The rectangle under the engine is usually the first part of an Anderson driveway to lose its coating. The reason is chemical, and it is fixable before the sealer goes down.

The Spot Under the Engine Is Not the Same Pavement

Asphalt is stone held together by a petroleum binder. Motor oil, transmission fluid and power steering fluid are petroleum as well, and they do to that binder roughly what a solvent does to glue. A drip does not sit on the surface the way a spilled drink does. It works down into the mat and softens the material holding the aggregate in place.

That is why an old parking spot looks different even after it has been cleaned. The surface reads darker or slightly glossy, the texture is smoother than the pavement around it, and the area gives a little more underfoot on a warm afternoon. The stain is the visible part of a change that went deeper than the stain.

Why Sealer Will Not Bond to It

Sealer is a surface film roughly the thickness of a business card. It has no structural job. It works by gripping a clean, slightly open surface, and once cured it keeps water and ultraviolet light off the asphalt underneath.

An oil residue defeats that grip completely. It behaves like a release layer, the same way a greased pan keeps a cake from sticking. A driveway can be coated evenly from apron to garage and still fail in one rectangle, because that rectangle never bonded in the first place. It shows up as a film that lifts at the edges, a patch that tracks onto tires during the first hot week, or bare gray asphalt the following spring after a winter of plowing and brine.

What Has to Happen Before the Sealer Goes Down

On an older Anderson driveway with a history of drips, the prep sequence decides the outcome more than the product name does. Most of the value in driveway sealcoating happens before the tank is opened, and oil spots are the clearest example of it.

• Scrub the spot with a degreaser rather than rinsing it, because plain water pushes the surface film around instead of lifting it out.
• Let the area dry completely afterward, since a damp spot traps moisture under the coating and produces the same peeling by a different route.
• Prime the spot with an oil-spot bonding primer, which gives the sealer something to hold that contaminated asphalt cannot offer on its own.
• Probe for softness while the spot is exposed, because pavement that gives underfoot or sheds loose stone is a repair question rather than a coating question.
• Hot rubber crack filling comes after the spot work and before any sealer goes on, which is the order the maintenance sequence calls for.
• Seal last, at the coverage rate printed on the pail, in two coats on most residential work.

When a Spot Is Past Priming

Primer solves a bonding problem. It does not rebuild a binder that has already been dissolved. If the parking area has gone spongy, if aggregate rolls loose under a thumb, or if the spot has settled into a shallow depression that holds water after every rain, the asphalt itself is compromised and a coating over it only postpones the question by a season.

That is a job for asphalt patching: cut the failed material out, replace it, let it cure, and seal the surface as a whole afterward. It is more work in one year and considerably less over the next ten. The maintenance order used across this site puts patching ahead of sealing for exactly this reason. Sealer cannot stiffen a soft base and it cannot bridge what is already open.

Why This Is the Common Case in Anderson, Not the Rare One

The median Anderson house was built in 1961, and the way driveways fail here has as much to do with that age as with the soil underneath. Those driveways have been overlaid, patched and resealed for six decades, and most of them have held vehicles from several generations of engines. Drips accumulate in the same rectangle year after year for the simple reason that people park in the same place, which is also why the failure lands in a neat rectangle rather than scattered across the drive.

Freeze and thaw then compound it. An oil-softened area is more open than the pavement around it, so it takes on more water, and water expands roughly nine percent when it freezes. The spot that would not hold sealer is also the spot most likely to crack, and a crack is a pipe delivering water into a base that has no way to get rid of it.

Timing the Work Before the Anderson Season Closes

Degreasing adds a step and a drying window to a job that already runs on the weather. Sealer needs pavement at roughly 50 degrees F and rising to bond and cure, plus about 24 dry hours after application. In September those conditions still appear regularly. By mid-October they stop being reliable, and late May or June is the realistic restart.

Spot priming and patching are priced separately from the sealcoat itself, which is worth knowing when the sensible way to compare two bids is by scope rather than by total. If the rectangle under the car failed last season, this fall is the time to settle whether it needs a primer or a patch instead of repeating the same coat over the same contamination. That question is where sealcoating for Anderson driveways and the nearby towns starts on an older drive.

More from the blog

• One Coat or Two: How to Read a Sealcoating Quote in Anderson
• Pothole Repair in Anderson: Throw-and-Go Cold Patch vs Cut-and-Fill Hot Mix
• Driveway Ponding in Anderson: What to Do About Standing Water