A driver wondered about sludge building up under his oil cap, despite doing regular oil changes. A mechanic gave him two explanations: One is fairly benign, and the other attributable to a defective part.
The wisdom came from creator Rich (@fordbossme), a mechanic who makes TikToks for a car-centric account, fielding questions from viewers. In this question, the audience member claimed to make regular oil changes every 5,000 miles, noticing a “lot of sludge under my oil cap and in the filler neck.”
The first possibility floated by Rich had nothing to do with how the driver was treating the car or driving the car, but where the driver might be living.
A factor to take into consideration
“Let’s talk about one factor to take into consideration is humidity. If you live in a high humidity area and there’s more humidity in the air, you have more chance of condensation building up in areas that are the upper portion of that object that may be getting hot.”
Rich uses an example of a glass of cold water that you take outside on a hot day. It’s likely for condensation to form, and for the glass to start “sweating on the outside.”
“In order for you to get rid of that condensation, you have to get the water inside the glass up to a certain temperature so it stops producing condensation,” Rich observes. “What’s happening is that hot air is being attracted to that cold glass, and the moisture in that hot air is being cooled down, and it’s basically the byproduct of the two meeting each other. You get water droplets.”
He then points out, “It’s the same with an engine. That engine is cold on startup, and then if you especially do short trips, you just go, you know, a half a mile, a mile, you know, you’re not running the vehicle long enough to actually burn all the moisture off that actually gets down in the oil in the crank case. And when it does start to burn off, you don’t let it fully burn off with running it like that. What ends up happening is it finds the highest point in the engine to accumulate.”
That doesn’t necessarily mean, though, that an engine part isn’t to blame—or at least contributing to the sludge creation. Rich then explains that a “PCV that’s malfunctioning will not allow a flow of fresh air,” and the fuel vapors can’t adequately escape.
Most of the time, however, it has to do with drivers making short trips before all the moisture has time and the right conditions for burning all of that off.
A PC-what now?
Doc Able’s Auto Clinic adds some insight on the PCV that Rich referenced.
“PCV stands for Positive Crankcase Ventilation,” the article states. It explains that crankcase is located at the bottom of an engine, containing a reserve of motor oil.
“When fuel is burned in your engine, it produces waste gases that are mostly vented out through your exhaust system,” the article reads. “But some of these gases push their way past the pistons and into the crankcase. There, these gases can mix with motor oil to produce oil sludge, which can damage vehicle engine parts through corrosion and by clogging engine passages.”
Before 1964, the gases collecting in the engine would just be vented off into the air. But even well before current climate change concerns, laws were passed requiring the gases be recaptured, thus leading to PCV technology.
Everybody’s an expert
Some looked to match car knowledge with Rich.
“Sounds like this guy would benefit from BG EPR,” one suggested, referring to a product called BG Engine Performance Restoration. “A lot of people do short trips, especially in cold weather, and never let the engine get up to full operating temperature. That’s a recipe for sludge.”
Another suggested, “Do oil samples at 5k and judge from there. I pulled samples on everything on the farm 14 years ago at normal interval. Went to 10k on everything but semi truck that went to 20k based on samples.”
Rich felt the need to weigh in with a response. “Yeah, but your method is useless honestly in the grand scheme of things. See, I don’t speak in individual instances, but—they are not sending oil samples in, bud.”
“Hence why the newer hybrids are calling for 0/16 oil,” someone else opined. “Engine oil temps have a more efficient chance of reaching 212° quicker.”
Rich, responding to the Daily Dot’s request for comment, was surprised that the video got as many views as it did. “I received a question from someone who was looking for a little education on the matter,” he explained, “and did what I do best and that’s help people and answer questions.”
@fordbossme Replying to @buckslayer__94 ♬ original sound – Rich
He then added, “Some responses I think are very intelligent and thought out and some seem to be professionals but others, which are most, are way out there in their own delusional world. But that’s human beings, right? We are flawed and I accept that.”
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