Multiple Misfires

[StarPower]

On Saturday evening I had multiple misfires as I was pulling out of a parking lot. I had been driving for a while (mostly highway using smart cruise control). I stopped for a few minutes at a convenience store to get a drink. As I was leaving, I started the car, reversed out of the space, pulled forward to the street, stopped for about 15 seconds to wait for a hole in traffic, then pulled into traffic (moderate throttle, normal drive mode). As I did so, the car seemed to lose power momentarily and the check engine light began flashing before illuminating steady. Bluelink reported multiple events and recommended I visit the dealer. I did not notice any abnormal driving after that one event.

The dealership scanned for codes and test drove it today, but could not find a problem. They stated that the stored codes were for misfires on multiple cylinders, that only happened once. Car has been driven approximately 7,000 miles.

Has anybody else had something similar happen?

 

[Midnightsun]

I had a similar experience except mine ran poorly as in missing a cylinder and only backfired a couple of times. Sounds similar but could be totally unrelated. Here is the thread. http://genesisowners.com/hyundai-genesis-forum/showthread.php?t=15453

 

[amartz]

As I was leaving, I started the car, reversed out of the space, pulled forward to the street, stopped for about 15 seconds to wait for a hole in traffic, then pulled into traffic (moderate throttle, normal drive mode). As I did so, the car seemed to lose power momentarily and the check engine light began flashing before illuminating steady.

Sounds like water in the gas to me. Especially since it happened just after you swung a sharp turn to get into traffic. Maybe try some dry gas if it happens again. And where did you buy your gas the last time or two, anyhow??

 

[Alwaysforward]

11,000+ miles on my 5.0 with zero issues. I only purchase Mobil gas and since completing my test between regular and Super Unleaded fuel, I only burn Super Unleaded. What kind of gas do you burn? Manual recommends Top Tier gas only.

 

[jarred52]

11,000+ miles on my 5.0 with zero issues. I only purchase Mobil gas and since completing my test between regular and Super Unleaded fuel, I only burn Super Unleaded. ]

What were the results of your regular/super test? I did a very unscientific test on my 3.8 in both city and highway driving with no discernible difference.

 

[Alwaysforward]

11,000+ miles on my 5.0 with zero issues. I only purchase Mobil gas and since completing my test between regular and Super Unleaded fuel, I only burn Super Unleaded. ]

What were the results of your regular/super test? I did a very unscientific test on my 3.8 in both city and highway driving with no discernible difference.

Here is a link to that test. I think you will find the answer around page 8 of this post.

http://genesisowners.com/hyundai-genesis-forum/showthread.php?t=15087

I seen an improvement with Super Unleaded in a combined average between city & highway driving. I have been averaging 21 mpg (calculated) using Super Unleaded which you cannot beat with a car that has 420 hp. I was getting around 19 mpg with regular unleaded fuel. In all cases it was with 10% ethanol.

 

[StarPower]

I usually fill up with 93 octane at an Exxon station on the way home from work. IIRC I had filled up the day before at that station. Even if I don't use that particular station, I always use Top Tier gas. Aside from that one moment, it's been running perfectly. I don't think it's the problem Midnightsun described, since his seems to be a longer-term problem, although mine could be unless mine is just beginning to fail.

It almost felt like an extremely rough shift, so I wonder if it might be the transmission issue from moisture in the taillights. I doubt that's it because it had been dry for several days, but it was also very humid and starting to cool off as evening fell. The parts for the recall are currently on order.

If it's a component that's just starting to fail, then I can hopefully get it diagnosed properly once it gets worse. I'd actually prefer it to happen again so that I can get it fixed. If it never happens again, I'll always wonder what it was and when it's going to surprise me.

 

[Alwaysforward]

I had a Transmission hick-up and since they did the recall, no issues. Maybe that is what you had. Here is my post on the issues I had. See if this sounds like the same thing.

http://genesisowners.com/hyundai-genesis-forum/showthread.php?t=15983

 

[Genesis5.0]

where in the manual does it recommend "Top Tier" gas? I only see regular unleaded gas. That in fact is one of the selling points for Hyundai that their engines only require regular unleaded gas.

 

[ksoze]

where in the manual does it recommend "Top Tier" gas? I only see regular unleaded gas. That in fact is one of the selling points for Hyundai that their engines only require regular unleaded gas.

The manual does state to use Top Tier gasoline (Section F8 & 7-9). You may be misunderstanding the term Top Tier, which refers to detergent gas available in all grades (including Regular unleaded) at most gas stations.

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[Genesis5.0]

Ah ok now that makes sense. Thanks for pointing that out.

 

[Torrente]

I have a 2009 Genesis sedan V8 4.6 with 25k miles on it. For a couple of months now I`ve been feeling some kind of transmission/engine failure. This only happens when I start from a stopped position and drive under 2,000 rpm. When the car changes shifts you can feel and see how the rpm fluctuate. If I accelerate faster the transmission doesn`t fail. This makes it difficult to know if it is a transmission problem or an engine failure. I took the car to the dealer and they have tried changing spark plugs, coils and gas, the problem hasn`t stopped. Anyone has an idea on what this might be?? Truly appreciate the help!