premium unleaded eliminates engine knock

[nextcar]

I've noticed for some time that when I accelerate up a hill, I would hear a noise in the engine area which sounds like engine knock. I've always used regular fuel. So last time, I switched to higher octane, and went up the same hill under hard acceleration. No more knocking.

Has anyone else noticed engine knocking under heavy load?

 

[Stoofpilot]

Not any with my 4.6 running regular.

 

[Cut-Throat]

I've noticed for some time that when I accelerate up a hill, I would hear a noise in the engine area which sounds like engine knock. I've always used regular fuel. So last time, I switched to higher octane, and went up the same hill under hard acceleration. No more knocking.

Has anyone else noticed engine knocking under heavy load?

Yes, this was well known to me in the 1960s with the big V8s ------- I am surprised that the Genesis knocked though...

I always run Premium in my Genesis.....no real reason however.

 

[TJPark01]

I've tried several different brands of 87 and 91. Under penalty of death I couldn't tell the difference. So I just buy the 87 and go about my day.

 

[Jimmmmbo!]

Be very careful. Engine knock is NOT something to just put off.

I had a car that knocked for several months and then ended up in a graveyard.

Take your car to the dealer for an analysis WITH a full tank of REGULAR fuel, even if it takes 1000 miles to ensure the fuel octane in your tank is completely in the "regular" category and the problem has a good probability of being reproduced. If they say nothing is wrong, GET IT IN WRITING and make sure it is RECORDED IN YOUR VEHICLE HISTORY WITH HYUNDAI.

I'm using caps for a reason. Hyundai has a 10 year / 100Kmile warranty. If you don't record the first obvious symptoms of a problem with them they have every reason in the world to ignore you long down the road. This is Hyundai, not Rolls Royce. Protect yourself first.

I love my Hyundai Genesis (and Elantra). But they are still a business, and you can't expect them to look out for your best interest when providing a lower-cost product.

Just my 2 cents.

 

[yellow3.8track]

The computer should be sensing the knock (premature ignition of the fuel/air mixture and retarding the timeing to help control/eliminate it.

It that's not happening you really need to follow the advice above and get your car to the dealer - as many times as it take to get it fixed.

 

[nextcar]

thanks for all the advice.
but, has anyone paid attention to their car when accelerating uphill?
do you really not hear any knocking under heavy acceleration?
i'm not talking continuous knocking but just a few clatter type of noise.

 

[yellow3.8track]

Nope. Every trip we made this summer we drove the coupe. Afton Mt. over on I 64 is long/steep but the mountain west of Lexington (VA) seems even steeper. As a "test", on our first trip, I started off at 65 in 6th gear and pushed the pedal down. In no time at all I realized we were about exceed 100 mph and I let up but kept it at 98 while I asked my wife if she wanted to be in the car while we bumped up over 100. She said no and I let off and dropped back to the speed limit.

No noise at all other than the engine exhaust note getting louder as we accelerated and the rpm increased.

I've never noticed here in the flat lands either when accelerating (heavy or normal). I bought a 6 speed manual because I want to control the rpm (tired of turning enough rpm at 45 mph to be doing 70-75 mph because the car just hasn't quite gotten to the point where it will go into overdrive and drop back to 1500 rpm.

With the coupe I'm often in 6th gear at 25 mph at just over 1000 rpm and it will accerate without pinging.

 

[ImInPA]

You should not experience knock with a quality 87 octane fuel. You are either getting poor quality fuels (not uncommon in certain areas) or you may have a bad knock sensor. It is likely that it is just poor gas in your area (assuming you have tried another brand). The high test gas probably brings it up to the range acceptable to the engine.

 

[Mark_888]

You should not experience knock with a quality 87 octane fuel. You are either getting poor quality fuels (not uncommon in certain areas) or you may have a bad knock sensor. It is likely that it is just poor gas in your area (assuming you have tried another brand). The high test gas probably brings it up to the range acceptable to the engine.

Could also be minor internal damage to the engine, such as might have occured with a misfire on the Tau V8 after shutting the engine down before warm-up, and then restarting.

______________________________

Help support this site so it can continue supporting you!

 

[sandy]

Yes, this was well known to me in the 1960s with the big V8s ------- I am surprised that the Genesis knocked though...

I always run Premium in my Genesis.....no real reason however.

This will be no help to the OP, but in the old days the knocking/pinging could be useful. I set the timing on my 65 XKE by following the owners manual......statically set timing to 10BTDC, put in 4th gear and nail it going up a hill, if it pings retard timing, repeat process until pinging stops.

 

[Admckillip]

Tested mine tonight by pushing it WOT on a pretty decent hill and the only noise I heard was the low engine rumble. I agree that you should get yours looked at...