Here's What Those Colored Markings Mean Under Your New Car's Hood

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Ever announcement those weird, brightly colored lines nether nan hood of a caller car and deliberation nan assembly-line robot must person had a small excessively overmuch nosy pinch nan overgarment pens? Well, those yellowish and blue — and sometimes different colors of nan rainbow — marks aren't a motion of a statement astatine nan factory. They're a silent connection that tells a communicative of quality, precision, and safety.

These marks are a important portion of nan value power system carmakers trust on. Think of them arsenic a mill worker's type of a checklist. A speedy swipe of a marker tin mean a bolt has been tightened to nan nonstop correct spec, a portion has passed inspection, aliases a constituent is installed successful nan correct orientation. They're a high-speed, low-tech solution, ensuring that each nan hands building your car did it nan due way. So knowing nan intent of those yellow and bluish squiggles gives you a peek into nan attention to item that goes into building a car.

To understand what these marks mean, you person to cognize there's a hierarchy. The astir basal type is thing called a witnesser mark, a elemental statement drawn crossed a seed aliases bolt and nan aboveground it's tightened against. If that statement ever breaks, it's an contiguous ocular motion that nan fastener has loosened, a instrumentality utilized everyplace from firearms to title cars. 

But nan automotive world takes it a measurement further pinch thing called Torque Seal, a brittle business paste applied to captious fasteners aft they've been torqued to spec. Once this paste cures, it's designed to ace if nan bolt moves moreover a mini bit, providing an instant impossible-to-miss awesome of a imaginable problem. Torque Seal is besides communal astatine quickie lube spots, utilized to forestall fraudsters from dumping lipid and past blaming nan tech who performed nan service.

But what astir nan colors? Here's nan portion that mightiness beryllium a small disappointing: nan colors themselves don't person a cosmopolitan industry-wide meaning — astatine slightest from immoderate readily disposable communal knowledge. There's nary concealed decoder ringing that says yellowish is for suspension bolts aliases bluish is for brake calipers. The main extremity is conscionable visibility — picking a colour that stands retired against nan portion it's marking. Within a azygous factory, however, nan colors are apt portion of an soul system.

For nan mean car owner, these small marks are a bully thing. They're a motion of a thoughtfully assembled and checked-over vehicle, not a defect to beryllium scrubbed disconnected during your first wash. With humans still connected nan assembly lines — astatine slightest for nan foreseeable future — these checks and balances are a bully sign.

But for nan aspiring DIY mechanic, they service arsenic some a guideline and a warning. If you ever person to loosen a bolt pinch Torque Seal connected it — say, connected your brakes aliases suspension — you should ne'er simply tighten it backmost until nan aged lines match. That's a awesome measurement to undertighten aliases overtighten a captious part, which could person catastrophic results.

The original people is location to show it was torqued correctly nan first time. Once you break that seal, nan only measurement to do nan occupation correct is to usage a calibrated torque wrench and tighten nan fastener to nan manufacturer's nonstop spec, thing immoderate decent Jalopnik scholar should already cognize — but still worthy nan callout. As we each know, immoderate car repairs you should conscionable beryllium capable to do yourself. If you want to beryllium other professional, you tin moreover bargain your ain Torque Seal paste, overgarment pen, aliases grease pencil, and use a caller witnesser people aft you're done.