Skip the auto shop - Our mechanics make house calls

Q: What's wrong with my car?

asked by on

It sometimes hesitates to start and will sometimes puff out white smoke out of the exhaust but not often. A few times I've smelled coolant while driving but not recently. It's slow on acceleration from a stop and once cut off on the highway. It now feels like it doesn't want to accelerate after changing spark plugs. I couldn't go over 25mph before then. It is also shaky when I drive it and the coolant runs out fast. Also one day my oil was clumpy on the stick when I checked it but it hasn't done it again. Please help me, thank you.

My car has 142150 miles.
My car has an automatic transmission.

A: Hi there, thanks for writing in. Without be...

Hi there, thanks for writing in. Without being there to inspect your Nissan Altima’s engine on site, it’s very hard to give you an exact diagnosis. However, the white smoke and smell of coolant leads me to believe that you might have a blown head gasket or it’s leaking. The white smoke tends to be caused by coolant in the oil. If the oil is "clumpy" or "milky" this is also an indication that you’ve got coolant leaking inside your engine block. Best bet is to have a professional mechanic inspect your vehicle for smoke coming out of the exhaust pipe. This will allow them to eliminate some issues and pinpoint the source of your problems.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Hesitation when accelerating from stop.

Hi, there is a list of possible problems that could cause the hesitation from a stop on this engine. The intake system is known to have vacuum leaks and also coolant leaking into the intake. The mass air flow sensor...

Q: The dealer can't reproduce the car shaking as if it's going to stop when A/C is on and car is idling.

This problem may be related to a dirty or failing idle air control valve. This valve reads the air intake as it enters the fuel injection system while being mixed with fuel and relays this information to the computer. The...

Q: Car wont stay running with a new battery

Hi There, It sounds like you may have a faulty voltage regulator that may be over charging your battery. You may have a failing voltage regulator that could be allowing the alternator to supply too much or too little amperage...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...