Q: Bad gas in tank of 1994 Pontiac Bonneville

asked by on January 25, 2016

My car won't go over 30 MPH. The battery failed and I had to replace it. The part store said the alternator and starter are good, but I still can't get it to go over 30 to 40 MPH. The other day I heard sounds coming out of the tailpipe, along with some white to light gray smoke. My first thought was I had put in some bad gas as my problems started when I filled up at a local gas station. I added fuel injector cleaner while I was at the auto parts store.

The first thing I would check would be for codes on the computer. If there are no codes present you could have a clogged catalytic converter. This is where the honeycomb inside the catalytic converter becomes so clogged that it will not allow exhaust gas to pass through it bogging down the engine. The white smoke coming from the tailpipe could indicate a blown head gasket. This is where the car overheats and warps the head and causes water to pass by the gasket getting into the engine. Your car would probably run very rough if this were the case. A leak down test can be performed to check and see if in fact you do have a blown head gasket by a qualified technician.

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

Car can't engage gears.
The transmission on these cars have alignment dowels that align the transmission to the engine. the problem happens when the transmission has been removed for a reason. The reinstallation alignment of the transmission is not correct because the dowels are...
I hear a clink sound when I put my car in reverse
My guess is that you have a bad transmission mount or motor mount (https://www.yourmechanic.com/article/how-long-do-engine-motor-mounts-last). You probably noticed this more when the engine is cold because the idle is higher. A trained professional, such as one from YourMechanic, will be able...
Bad gas mileage, engine misfire - 1992 Cadillac Allante
There can be multiple causes, but it sounds like your fuel injection (https://www.yourmechanic.com/services/fuel-injector-replacement) is injecting too much fuel into the engine for the amount of air it's using. Faulty temperature, air flow, or oxygen sensors (https://www.yourmechanic.com/services/oxygen-sensor-replacement), a dirty throttle body...
steady ticking sound from ac compressor
Hey there. The one in the video has a major problem with the pulley bearing getting ready to seize up. You can hear the noise when the A/C compressor turns off. These bearings will start to spin on the front...
I am installing a timing belt on a crate motor. The intake side camshaft tdc marks do not line up perfectly like the exhaust side
Hello. If there was not a timing belt on the engine already then you need to be careful about turning everything. As long as you are taking it easy and being vigilant of any binding you can turn each of...
Grinding noise while braking - 2006 Porsche Cayenne
Okay, so with brakes, the concept is fairly simple and hasn't changed much over the years. You have a rotating disk and it is being squeezed on both sides by a pair of pads. If you are hearing a grinding...
If a speed sensor on a 08 Dodge Caliber goes will the car drive real slow
It is possible for a speed sensor to limit the throttle opening since the failed sensor system can cause the powertrain to get damaged or not know how fast you are going and will cause failsafe mode on some vehicles....
I keep hearing a popping/clunking sound on the right front passenger side of my truck near the right tire.
The sound might be related to a worn suspension component. From what you are describing, it should be fairly easy to pin down with static testing (e.g., ball joints should only move "so much" during a test). To pinpoint the...
2001 honda crv, broken timing belt, probably valve damage, could repair for <$1000 be likely?
Unfortunately if the valves have been damaged the engine will likely require replacement. With the cost of a new engine and the labor time to put it in I would imagine that a repair such as this would cost over...

Related articles

What Is E85 Ethanol?
E85 E85 ethanol is a fuel that can be used to power internal-combustion engines. Some vehicles can use E85 and gasoline, while others are tuned for E85 only. E85 is named as such because it is 85% alcohol. The other...
What Prevents the Fuel System From Leaking?
Leaking Leaking fuel is a hazardous and wasteful problem for a vehicle to have. Manufacturers know this, and to combat the problem they have implemented a number of simple ways to prevent fuel from leaking out of the fuel system:...
How to Replace a Fuel Hose
The fuel hose goes bad when there are visible leaks under the car or cracks in the hose and when gas vapors are smelled around the car.