Engine observations

I put 120 miles on last night in sport and noticed the ICE noise a couple of times. No big deal. I was hauling butt and got 20 mpgs. I then drove the rest of the way in stealth, 25 miles, and my mpgs went to 32.

The noise I'm referring to is different than the background ICE hum/rumble... Its isolated and sounds as if it's coming from just in front of the driver's feet... Or slightly to the left of that. Is that what you've noticed too?

ffcars said:

I put 120 miles on last night in sport and noticed the ICE noise a couple of times. No big deal. I was hauling butt and got 20 mpgs. I then drove the rest of the way in stealth, 25 miles, and my mpgs went to 32.

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After driving 120 miles in Sport, what did the battery gauge read?

I believe my Karma may have an issue, because I never see the battery gauge adding miles when in Sport. I typically only use Sport when the battery gauge is 0, and I never see it move off 0, even after driving 20-30 miles in Sport.

What are the rest of the owners seeing?

Dennis, that feature was changed in production cars. Sport no longer adds Stealth miles but rather maintains whatever level of charge is in the battery at the time you engage Sport mode

Dennis, have you experienced this noise I described sometimes in Sport mode?

SoCalGuy said:

Dennis, that feature was changed in production cars. Sport no longer adds Stealth miles but rather maintains whatever level of charge is in the battery at the time you engage Sport mode

Dennis, have you experienced this noise I described sometimes in Sport mode?

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I noticed that when in Sport mode my battery miles (if not 0) would go down. I guess that is possible if you are accelerating hard and trying to get all 400 hp to the electric motors, right?

I am not aware of the grumbling noise as you describe it. I have a different ICE noise issue. At certain RPM's, there is a buzzing noise, which sounds like thin metal resonating. Could be a loose heat shield, I guess. I've reported it to the dealer and they plan to address it when I take the car in for the 6.13 upgrade.

When I go SF on Tuesday (100 mile roundtrip) I will be attuned to all ICE noises.

I hear an occasional HARSH buzzing/fast rattling noise as well. It may be different characterizations of the same noise, as it happens at fairly low RPM. I was going to ask to drive another Karma at the dealer next week and see if it has the same noise signature.

The noises you describe - does it seem like it's coming from just in front of your feet?

In my case, yes - the noise appears to come from the exhaust ports or the manifold/piping leading to them. So, just in front of the steering column.

Fnorrod said:

In my case, yes - the noise appears to come from the exhaust ports or the manifold/piping leading to them. So, just in front of the steering column.

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My buzzing noise comes from the engine compartment on the passenger side. I just drove the car in Sport mode and heard about 5 seconds of the "blender" sound in front of me about 1 mile into the drive. My first reaction was that it was coolant moving, and it went away very quickly.[hr]

SoCalGuy said:

Dennis, that feature was changed in production cars. Sport no longer adds Stealth miles but rather maintains whatever level of charge is in the battery at the time you engage Sport mode

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I just drove the car in Sport mode + Hill Mode 2 to the grocery store and back with a full charge (49 miles) on the battery. The ICE did not turn on for the first 1/2 mile, most of which is downhill. At that point battery range said 47 (it always comes off 49 very quickly). When I got to the store (2 miles total) battery still said 47. On the return trip, ICE was on the entire time, battery went to 45, as there is some uphill.

The computer reported 30mpg. I used 1/2 as much battery as the same route in Stealth. So I guess it is functioning correctly.

I've also heard a rumble, but I attribute this to the changing revs of the engine. It could also be the generator. It only happens when the battery is completely depleted. It doesn't happen when you engage Sport Mode when the battery is still full or half full.

So if you're going on a long trip (on which you know you're going to have to use Sport Mode) and you want to avoid engine rumble, you simply engage Sport Mode when the battery still has charge left.

I've driven 750 kms (470 miles) so far and used 25 liters of gasoline (6.25 gallons), so I am getting 75 miles to the gallon. I think this will improve when it gets warmer and the range on my daily commute improves.

Heard it again today a few times. The most noticeable/long instance was when I was driving up a curved long hill. Battery had 24 miles of range and I was maintaining about 50mph... It lasted probably 6s and then off and on a few times.

Last night I started my 120 mile trip with a full charge and drove in sport. It drained the miles from stealth until it got down to 26 miles left. At that point the stealth miles never went down.

ffcars said:

Last night I started my 120 mile trip with a full charge and drove in sport. It drained the miles from stealth until it got down to 26 miles left. At that point the stealth miles never went down.

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OK, so that says that the "maintain" level is 26 miles (and apparently the "charge up more" level is 0).

Now if only we could tweak these with control panel settings...