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Top 5 signs you're headed for a major car repair

Before you head out on a road trip, make sure you car isn't doing any of these things.

GIF by Brian Cooley/Roadshow

Modern cars accept an amazing amount of abuse. But if you keep gas in them and do an occasional oil change, they'll just keep running. Still, they don't have endless durability. Car noises and warnings lights indicate something pretty drastic and expensive is about to put you in serious need of car repair. Here are my five top indications that you're about to go for an unplanned walk.

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Engine light

Many cars cheat you out of meaningful gauges and, instead, give you an "Engine" light that represents overheating, low oil or a number of other serious conditions. Don't mistake this for the "Check Engine" light that your car may also have and which often indicates a less critical emissions system problem. Know which engine status lights your car has and which one indicates that you'll soon need a bus pass.

engine light

Know the critical difference between an Engine light and a Check Engine light.

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To divine what the Engine light is complaining about, invest in an inexpensive OBD code reader that plugs into a port found under the dash of any car sold in the US since 1996. There are readers that wirelessly show the the problem via an app on your phone, or cabled readers that don't requite a phone at all. Here are examples of each type that I've had good luck with on my cars.

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Actron makes reliable dedicated code readers that require no smartphone and will usually spell out what your car's "Engine" light and trouble code mean in plain English.

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The Bafx Products wireless Bluetooth OBD code reader is a solid way to get codes from your car when the Engine light comes on. It may also be able to temporarily clear the code to verify it's not a false indication. Bafx also makes a version of this device for Android phones.

Tire pressure light

Cars sold since late 2007 must have tire pressure monitoring system sensors, and at least a basic dashboard light that tells you if the sensors have found a problem with your tire inflation.

TPMS tire pressure sensor

A typical TPMS sensor, which is installed inside each of your car's tires.

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Many cars also have a detailed dash readout that tells you which tire is low and by how much. In any event, a TPMS system must give you a warning once any tire gets 25% below proper inflation. That may not sound too bad, but driving with a tire at 19 PSI instead of 26 PSI is a big step toward your car entering another lane without your involvement.

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Groaning brakes

This is not the same as squeaking brakes. Groaning brakes generally mean you've worn past the actual brake pad material and are now down to metal-on-metal contact in your braking system. This renders results that will be, um, unpredictable. You have also now set yourself up for a more expensive brake job. Stop now (if you can) and get your brakes serviced.

Metal on metal brake pad wear

An ugly sight: The pad on the top has been worn down to the point that it's metal backing plate is contacting the car's brake disc. The pad on the bottom is what it should look like, with a healthy thickness of pad left on the backing plate.

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Rattle on start

When you start your car, does it sound like someone's rolling a coffee can full of nuts and bolts? That's often a sign of virtually no oil pressure or a failing valve timing system, or both. There is no low-priority version of this death rattle. Stop now, check your oil level and if topping that up doesn't remedy the noise, get your car into a shop before an already expensive repair turns into an impossible one.

Overheating

So much has changed about cars, but this hasn't: Heat kills. Overheating warps parts, cracks castings, loosens gaskets, melts plastics and can even set your car on fire. Overheating is also the most pervasive engine problem, afflicting the entire engine when it happens.

High temperature gauge

This 1967 Mercury is doing something modern cars almost never do: Running quite hot. If your late model car runs up near the top of the temp gauge or gives you a temperature warning light, take it seriously.

Brian Cooley/Roadshow

Modern cars almost always run close the correct temperature, unlike older cars which might run in a wide variety of temps on their spacious gauges and still be "normal." If your modern car is showing a high temp needle or a heat indicator light, it's that much more alarming than it used to be.