What’s Wrong With My Car? Diagnosing Common Problems

You’ll likely need to see a mechanic, but how your car smells, feels or sounds can offer warning signs for common car problems.
Lacie GloverApr 30, 2018

Many or all of the products featured here are from our partners who compensate us. This may influence which products we write about and where and how the product appears on a page. However, this does not influence our evaluations. Our opinions are our own. Here is a list of our partners and here's how we make money.

If your car is vibrating, making noises or emitting odors, you'll probably be seeing a mechanic soon. But before you do, a few minutes of troubleshooting on your own will help you talk to your mechanic and budget for the .

We have suggestions for how to proceed if:


Sometimes a gas smell isn’t a harbinger of costly repairs. Assuming the odor isn't simply from your last stop at the gas station, it could be a loose or broken gas cap. A common culprit, gas caps are cheap to replace.

If the odor persists and it isn’t a faulty gas cap, it could be a more serious, and potentially dangerous, problem with your fuel system, like:

After your car gets some miles on it, you notice a little shake or rough idle here and there. Possible explanations include:

A little white vapor coming from your tailpipe that disappears quickly is likely just normal condensation evaporating.

But white smoke coming from the tailpipe that doesn’t dissipate quickly typically means coolant is leaking and burning when it enters the combustion chamber in the engine.

This can be a pretty serious issue, so be sure to find an experienced mechanic. Possible problems range in severity and include:

Repairs will likely set you back at least $1,000 — and much more if your engine must be rebuilt or replaced.

Smoke (or steam) coming from the engine or under the hood is probably the result of coolant leaking from its reservoir and reacting with the heat of the engine. Other telltale signs of a coolant leak: a sweet or syrupy odor and overheating.

Unless you left last week’s leftovers in your car, this smell is probably an indication that you need your catalytic converter replaced, a common and expensive repair.

Other possible reasons your car smells like rotten eggs include:

Normal wear and tear can take its toll on your car’s steering and suspension systems, which can complain loudly when it happens. Warning signs can take the form of:

Your non-starter probably falls into one of two categories: The engine cranks when you turn the key, or it's silent or makes a quiet clicking noise. You can narrow down the problem by its sound (or lack thereof) when you turn the key.

On a similar note...
Dive even deeper in Auto Loans