The owner of a 2006 Toyota Tacoma decided “to get this rusty old thing out of my life” and listed his truck on Facebook Marketplace. After just one showing, the truck no longer ran. He admitted he was “pretty embarrassed.”

Here’s how he told it. “One of them had me at the back of the truck talking about whatever while the other must have walked around and did his little scheme.”

The “scheme” had two parts. First, the buyers poured oil in the coolant inside the radiator. Then they unplugged the wire running to the V6 engine’s mass airflow sensor, forcing the truck into limp mode. The oil in the coolant made the problem look catastrophic.

“It was driven around the block when it started to lose power and then smoked because they poured even more on the engine block.” The situation escalated quickly. The check engine light came on. When the owner tried to restart it, the engine immediately shut off again. To anyone unfamiliar, oil in the coolant screams engine failure.

After the disastrous test drive, the buyers told the Tacoma owner the truck was junk. They claimed a blown head gasket or similar failure had dumped oil in the coolant system. They insisted the pickup did not have much life left. “They pressured me quite aggressively to still sell it anyways to them for way less than asking.”

Luckily, the owner grew suspicious. “I started to think something was up and held firm on my refusal.” He added, “Once I picked up on their bullshit, I just ran them off.”

How the oil in the coolant scam actually works

After the buyers left, the Tacoma owner started poking around under the hood. He noticed a stray wiring pigtail. “I believe it was the MAF sensor. Plugged it back in, started right up, and backed it into my driveway.”

None of the symptoms lined up with genuine internal engine failure. That raised even more questions about the supposed oil in the coolant. When he shared the story on Reddit, commenters quickly connected the dots. Several theorized the scammers spilled oil on the engine block while pouring oil in the coolant. Others suspected it was deliberate to sell the illusion.

In the comments, the owner said he planned to flush the coolant with help from a mechanic friend. Removing oil in the coolant quickly matters, but it does not automatically doom an engine. He even found a silver lining. “It’s my excuse to finally learn to work on my own vehicles.”

The poster took responsibility for the situation. “I broke the Facebook golden rule of always have someone with you when you try to sell something, but I was tired.” He concluded, “I’ll pay the stupid tax and move on.”

One commenter offered reassurance. “Don’t be too hard on yourself. I’ve only purchased and sold used cars from craigslist/Facebook about 10 times and not once has this ever happened.”

I agree with that take. This is not a common scam most sellers expect. Still, if the story is accurate, the oil in the coolant scam is destructive and mean-spirited. If you sell a car privately, do not let tire-kickers access the engine bay unsupervised. You can see the original Reddit post embedded below:

Was scammed trying to sell my car
byu/LawPup23 inAskAMechanic