Q: I have a problem of petrol going through to the oil sump and the car backfire and some smoke coming out of exhaust.

asked by on November 23, 2016

When I start the car it idles ok when cold and when getting warm it start to idles rough and smoke coming from exhaust,when I rev the car it backfires from exhaust,and I can smell petrol from the exhaust.After switching it of and checking the oil,the oil is full of petrol and oil is very light because of petrol mixing with it.i have changed injectors thinking that it inject too much petrol but nothing has changed.
My car has an automatic transmission.

Smoke from engine or exhaust Inspection $94.99 - $114.99 Get a Quote

Hello. If your oil is being mixed with fuel then you are either getting too much fuel into the engine or you have a serious internal engine issue. Most of the time this is caused by worn out piston rings. If the rings are worn out then the fuel will bypass the rings and enter the oiling system. I usually do a compression test to verify if this is possible. If the compression is fine then I suspect that the computer is commanding too much fuel into the engine which is usually caused by a failure in the computer or an issue with one of the sensors. I use a scan tool to check the sensors first and then test the computer from there if needs be. If you want to have this fuel in the oil checked, consider getting some help from YourMechanic, as a certified mechanic can come to your home or office to [diagnose why there is too much fuel entering the engine] https://www.yourmechanic.com/services/smoke-from-engine-or-exhaust-inspection

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Long trip
Hi Pedro, This is a difficult question to answer because I am unable to determine the condition of your particular car. Generally speaking, a well maintained car that is operating properly should have absolutely no problem completing a 5 hour...
Random crank but no start on a 2008 Kia Sorento
The on-board capabilities of your Kia are pretty high. When problems occur, the computer often memorizes them. A lot of times, it will turn the engine on and have the Check Engine Light on and give you a code that...
My 98 Jaguar xj8l won't start, clicking noise
This could be caused by a few things on your 1998 Jaguar XJ8. A low battery charge can cause this. If the battery is good, then listen for where the noise is coming from. If you get a click from...
Tire pressure light came on while driving to the airport.
Your tire pressure system uses sensors in each tire to signal the pressure in the tire. The sensors are known to go bad and will cause the system to see it as a pressure loss. This does not mean you...
my car is shaking and saying engine power source low
Hello, thank you for writing in. With the engine light on, you will need to take the vehicle to have it scanned for diagnostic troubleshooting codes. Power loss typically comes from electrical issues, fuel issues, or spark issues. With that...
Charging system light.
The charging system light will illuminate when the vehicle control system detects a problem with either the battery or the alternator. Typically, the alternator is the cause for the light. If the alternator is not able to maintain the battery...
Increased RPM and acceleration. 2013 Suzuki
Hello - the "Settings" error message, and the symptoms you describe, indicate the throttle position sensor (https://www.yourmechanic.com/article/how-to-replace-a-throttle-position-sensor-by-mia-bevacqua) has gone out of adjustment. Since it is adjustable on this model, this problem MAY be solved with a reset of the TPS,...
Does putting my car into accessory mode count as a key cycle on a scanner?
You have to turn it to on all the way to count as a key on cycle and then back to off for one key cycle.

Related articles

A Buyer’s Guide to the 2012 Volkswagen Jetta TDI
The The 2012 Volkswagen Jetta TDI is a great choice for any car enthusiast who needs a practical but fun car for everyday driving. The Jetta TDI (which stands for turbocharged direct injection) has a whole host of features to...
The Best Used Cars to Buy if You Live Close to the Ocean
If If you live close to the ocean, your vehicle is going to be far more vulnerable to rust than if you lived further inland. And the fact is, when it comes to resisting rust, not all vehicles are created...
Industry News for Automotive Techs: October 1-7
Wireless electric car charging, VW diesel scandal payouts, 3D-printed car technology, new Cardone car parts, and high September auto sales.