Q: Engine knocks, tailpipe blows white smoke

asked by on July 22, 2016

When I turn the engine on, the tailpipe blows white smoke out. The car is also shuddering. After I turn the engine off, it starts making a knocking noise. Is my engine going out or is it something else causing this?

Smoke from engine or exhaust Inspection $79.99 - $89.99 Get a Quote

Hello. There are a few things that can cause this. If the smoke is white then you may have a blown head gasket. This is a common failure on this vehicle, especially if it has ever overheated. If the smoke has a blue cast to it then it may have leaking valve stems seals.

I usually start by doing a compression test to see if there is an internal issue. If there is a compression problem then it is a head gasket problem. If the compression is fine then it will need new valve stem seals. Both cases will require some serious engine work be performed.

If you need to have this looked at, consider YourMechanic, as a certified mechanic can come to you home or office to diagnose the smoke and repair this.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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

What others are asking

My car stop cranking over

With a fully charged battery in good condition, and the immobilizer (security) system off - check to be sure the immobilizer is not activated - if the starter motor does not operate at that point, there are only two possibilities:...

I went out last night in my car everything was fine then I pulled up at the shop turned car off wen I got bak in it my steering wa

Hello, thank you for writing in. There are several reasons why your steering may have gotten hard. If there was low fluid, you have a leak that you will need to locate. When you locate that leak, you will find...

My battery drains itself like a ghost every now and then. Whats the problem?

Hello, thank you for writing in. The battery may be having several issues. If you have had the battery tested, and it passes all of the tests, then you are looking at parasitic draw. This is an electrical component, sensor,...

Fuel range indicator says I can drive 180 miles until empty. I drive half a mile and the indicator already says 165 miles left. What's wrong?

This calculation your car performs is a constantly varying calculation due to a couple of things. One part of this calculation is based upon the driving habits of the driver and how the throttle is used in combination with how...

oil leak from oil filter housing.

Hi there. There is not much of an easier way to remove the housing. However, look at the situation and look to see what needs to be taken off and what does not need to be taken off. If oil...

my trans malfunction warning light came on and 1st and second gear is slow. what can i do

When a module illuminates a warning light, generally there is a fault code that accompanies it. there can be many reasons for the concern like a low fluid level or a failing internal transmission component. Fluid leaks are common as...

Engine smoked and had unpleasant odor on 2013 Toyota Prius V

Hey there thanks for writing in about your 2013 Toyota Prius V. It sounds like you had a coolant leak and caused the engine or electrical motor to overheat and shut down. If you would like to have this looked...

D light indicator is blinking

Hello there, when the D light is blinking on the dashboard this means there is a transmission fault. Many different issues can cause this fault. The most common would be a low transmission fluid level, a mechanical transmission fault, a...

Changing control arm bushings on a 2009 Subaru WRX

Things can change but you'll need to replace it and that is a real pain. On that vehicle, they are very popular. So, you can go to any good aftermarket parts place and get an aftermarket control arm with the...

Related articles

A Buyer’s Guide to the 2012 BMW Z4
BMW’s BMW’s entry in the hardtop roadster segment, the Z4 delivers the ideal combination of performance, looks, and standard comfort features. This two seater is not only classically stylish and heavy on extras that aren’t, well, extra, it’s also the...
What Do the Belts on the Front of an Engine Do?
Car serpentine belts power multiple parts like the power steering pump and air conditioning. A broken engine belt can cause damage to components.
How to Prep an Engine Block for Paint
When When you are rebuilding an engine, you’ll probably want to paint the engine block. It serves a few purposes including being clean and attractive in appearance, protecting from corrosion and rust, and offering a custom look, even matched with...