Bad odor from the engine, engine vibrates when it idles?

BONNIE1959

MEMBER
2012 CHEVROLET CRUZE
4 CYL
TURBO
4WD
AUTOMATIC
122,000 MILES

I purchased the car listed above on July 26, 2021. Unfortunately, I did not look up the VIN number before I purchased the car. When I did, the list contained a number of problems. So I am concerned that this will end up being a lemon. I did have a diagnostic done by the dealership. They told me the car was okay. I find out the hard way that this is not a good way to check the car. The VIN number will let you know the condition of the car. Do you have any suggestions that will lead me in the right direction? How do I approach this with a mechanic? I live in Newport News, VA. Do you know of a good mechanic who will is trustworthy and fair?

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

The idea that it runs rough and you get a bad odor can be a couple of things. First, a rich fuel mixture (too much gas not enough air) to the engine creates an odor and a rough idle. Next, a bad catalytic converter can create a rotten egg odor and the vehicle can lose power and run rough.

Here is what I need to know: Does the check engine light stay on when the engine is running? If it does, I recommend having the computer scanned for diagnostic trouble codes. Here is a video showing how it's done.

https://youtu.be/u-4syLc-ifQ

I realize most people don't own a scanner, but oftentimes, a parts store will do it free of charge, so have it done if the light stays on or flashes.

Next, a rich fuel mixture can be the result of a faulty fuel pressure regulator or even an engine coolant temperature sensor. As far as the temp sensor, a scanner can be used to identify the signal being sent to the computer. The fuel pressure can be checked with a fuel pressure gauge.

Here is a link showing in general how it's done:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

I apologize, but I don't know of any shops where you are located. I'm near Pittsburgh. LOL

Here is what I suggest: If the check engine light is on, have it scanned and let me know what codes are present. Do that first and let me know the results. If the light isn't on, then check fuel pressure. If you don't know if the vehicle was ever tuned up, that would be a good thing to consider. It can cause issues as well.

Let me know what I can do to help you or if you have other questions.

Take care,

Joe