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Stalling and not turning off

What would cause my car to sputter (and sometimes die) after I add gas? At first it was just when I filled it. Now it is when I just put gas in the tank. (I turn it several clicks when closing) It usually sputters as I leave the station. It has stalled and taken several tries before it would run.

Also, what causes the motor to continue running after it is turned off? Today, on my way home,it stalled at a red light. When I arrived home, it would not stop running after I turned off the ignition and removed the key. I restarted it and when I turned it off, it did it again. The temperature was around 86 when this happened.

Could the two be related?

I don’t know what kind of car you have but you have a bad timing chain. Not a belt, a chain.
The sputtering after you add gas, you should replace the inline fuel filter.

Sorry, I forgot to add that it is a 2004 Santa Fe

That’s a weird diagnosis.

It could be multiple problems. The sputtering/stalling after filling up sounds like a problem with the vapor recovery/fuel tank vent system. It could be a flooded carbon canister, it could be bad solenoid vent valves, or it could be both.

The engine failing to shut down would have to be an issue with the ignition switch, if that is really what’s happening. Are you sure the engine is still running, and not just the fan?

When you “restarted” it, did you turn the key all the way to start? If you did, and you didn’t hear an unpleasant grinding sound, then the engine wasn’t really still running, just the cooling fan.

I am sure the motor was running not just the fan.
When I restarted it, I started it like I was starting the car. Turned it all the way to the right and it started… let it run a couple of seconds and turned it off… motor still ran.It ran a few seconds then it sputtered to a stop, like it was running out of gas. I have never had this happen before. I’ve never heard of it happening.
I thought the stuttering after filling with gas could be a vapor problem, but I always turn the cap several times when closing. When it first started I was always filling the tank at empty… thought maybe water in the gas tank. But then it started when I put gas in at 3/4 full… Thanks for your help…am going to try to have it checked tomorrow probably Thursday. Does this sound like it could be expensive??

This is a classic case of autoignition (known as “dieseling”). Does the sound coming from your engine sound anything like a diesel engine by any chance? This is not necessarily an expensive repair and much of it (if not all of it) can be done yourself. Before you do this, however, try not to drive the car around much more. Continued dieseling can damage your engine.


Thank you Techniker!!

I’m glad someone mentioned dieseling. Although I thought it mainly happened to carbuerated vehicles.
I agree with fuel related.

Sweetizzy, you’re misunderstanding Tardis. If you turned key to start position and it started okay, the motor was not running. Otherwise you would get this GRIND that i know that everyone with a drivers license has done, started car with motor on.

Now, please don’t get me wrong and I’m NOT calling you a liar. There could be a chance that the engine was turning over slow enough that when you engaged it, the starter caught the flywheel successfully.

Is there a check engine light on at all?
Sorry you have to take it in. Good luck. Take Technikers’ advice, don’t drive it until you can get it fixed. Be safe.


JP, you are correct, it is normally seen on older carbuerated vehicles, but I think there is a chance she has carbon buildup in the cylinders causing a preignition. My recommendation would to be to go ahead and try Seafoaming the engine. I can provide instructions if she is interested. I just find it hard to believe she would have that kind of carbon buildup at only 6 years old.

Sweetizzy, can you tell us if you notice the temperature gauge running higher than usual during these periods? Next time when this happens take a look and let us know. It could be something as simple as a bad thermostat or temperature gauge.


I think you’re right. And she could have that much carbon buildup if she (or someone else) has been putting premium fuel in it, thinking that premium is always better. Premium in an engine designed for regular gas can cause carbon buildup due to incomplete fuel burn.

First, let me tell you all, “thank you!”. This is all so confusing to me…
Don’t think it matters, but I have 116,192 miles on my car.

I use the lowest grade gas…occasionally a medium or hight grade is used, but not that often. I always make sure I turn the cap several times after getting gas.

I have started the car while the motor was running…heard the grind. But this was not last night. When I turned the car off and removed the key, the motor continued for a few seconds. After it sputtered to a stop and I thought “what the heck?”, I restarted the car.(I guess to make sure it would start) It started as it does every time. Again, I turned it off, removed the key and it continued to run a few more seconds until it sputtered to a stop. Sounding more like it was running out of gas than a dieseling sound.

There were no “you have a problem idiot” lights on. The normal lights were on as I started it then they went off as normal.

The temperature gauge was sitting normal, has not/ did not run hot nor cold.

Do you think the problem I have been having with the sputtering after fueling and the problem last night have anything to do with each other?

If it is autoignition, what would be involved with fixing it, if I chose to do it myself?

I have called & have an appointment tomorrow to have a diagnostic test run. I know it reads my cars computer, but will the diagnostic test show EVERYTHING that is not working correctly?
Do you think a shop like GoodYear or Firestone store will be able to fix it as well as the Hyundai Dealership? I just need to be informed before I go, and I do not need unnecessary expense. :slight_smile:

You have to be careful with the shops’ advice. Oftentimes disreputable shops will see dollar signs with a problem like this. Instead of just using a can of seafoam to fix the problem, they’ll want to disassemble the engine or some such nonsense. What your car needs is a seafoam treatment, which is pretty easy to do:

At your next fillup, pour 1/3 of the can into your fuel tank, and then fill the tank.

Then drive 10 miles from your oil change place, and pour 1/3 into the oil. Drive directly to the oil change place and have the oil changed (seafoam thins the oil, so you don’t want it in there any longer than necessary to clean).

Then use the remaining 1/3 can in your air induction - you’ll need to pull a vacuum line for this to suck the seafoam out. You probably know someone who can help you with this, since it’s the only tricky step.

That will clean out your motor, including the carbon buildup.

What’s happening is that unburned fuel is accumulating in your engine as carbon. It’s essentially the same stuff that’s in charcoal, and just like your grill, once you get it hot enough, it tends to slowly burn and release heat. When you shut your engine off, the fuel/air mix is not supposed to combust because there’s no spark from the spark plug to ignite it. But the hot carbon is hot enough to ignite it anyway, which makes the engine keep running until it’s starved of fuel.

When the ignition switch is turned off the ECM stops sending pulses to the injectors, so no more fuel should be injected to make the engine after run (diesel). Possible sources for the continuted fuel flow could be a leaking fuel injector, leaking fuel pressure regulator, or canister purge vaccuum valve stuck open. It is also possible that the canister is saturated with fuel and liquid fuel is being drawn into the engine on restart after a fill up causing the sputtering.

I think the source of the after running will also be the source of the sputtering. Sweetizzy you might try this test. Measure how long it takes to fill up or add gas and pay. Now stop somewhere and turn the engine off for the same time interval. See if you have the sputtering. If you don’t, do it again but this time remove and replace the gas cap before restarting after the time interval. You want to separate the act of filling from the time spent with the engine off.

Hope this helps you. Get back to us with results.

Okay, now we’re getting somewhere. You have changed your description to something that makes more sense. You implied that the engine never stopped until you “restarted” it. You are now saying that it stopped on its own after a few seconds. This is important.
It’s not dieseling like pre FI cars used to do. It is all a problem with the vapor recovery system. When you turn the key off, the vapor recovery system is supplying enough fuel vapor for the engine to keep running. The PCM will keep providing ignition sparks for a little bit after shutdown to burn off the last of the fuel that was injected.
Get the vapor recovery system fixed and your problems will go away.

Sweetizzy, I have your SUV and had your exact problem for at least 6 months until last night. The answer is the purge control valve (PCV) it is in between the fire wall and the engine just above the exaust manifold. You need to take the plastic cover off first (6 - 10mm socket bolts). Push the steel release wire in on the connector to unplug it. Disconnect the hoses on each end of the valve and slide it out of its bracket to the right. Replace it by these instructions in reverse. It took me all of about 10 minutes. I filled up my tank and bingo.

Oh yea… the valve is only $39 at the dealer. PS I hope you did not waste a bunch of time with these other suggestion above. Some are wayyyy out there. I went as far as removing the gas tank which was an all day job cause the drive shaft and exaust system was in the way.

Best Regards!

I hope you tell us what fixed it. PCV would be a great cheap fix.