Odd rumble when giving Kizashi gas from complete stop?

peezi · Wed Feb 05, 2014 8:14 pm

So, I'm new here, and I recently got a 2010 Suzuki Kizashi CVT AWD. I started hearing this odd rumble (almost like a muffler hole noise) when I give it a pretty good 'step on the gas' motion. If I barely give it gas it does not do this. The sound also goes away once I hit about 20 MPH or if I let up on the gas pedal. It also does not occur if I rev the engine in park or neutral. It actually went away for a bit, and that happened to be when I took it to the dealership (go figure). Unfortunately, the noise just came back, and I am wondering if anyone else has ever heard of this, or can give me ideas on what to do?

1 thing to mention, the car manual says put 87 octane into it; I put a couple tanks of 85 into it after my first tank of 87. The noise started after I started putting 85 into it, don't know if that is a co-incidence or not. I refilled with 91 and plan to use 87 going forward, what do Kizashi owners think of the gas octane for this car, is 87 necessary? Any problems noticed using lower octane than 87?

Wed Feb 05, 2014 9:11 pm

At first, I was going to say maybe an exhaust leak, but once I read you put 85 octane, I'm thinking it may be knocking. Knocking occurs when you put too low of a grade of fuel than the engine is specified for.
The Kizashi calls for 87 minimum so stay away from 85. Not sure where you even found 85. I've never seen anything lower than 87 in the United States.
Regardless, see if it keeps up with 91 and always use at least 87. Some people here use 91 or 93 and claim they get better fuel economy. I use 87 and have no issues.

If it keeps up, maybe use an octane additive, assuming your 91 is mixed with the 85. However, the knocking should go away with proper grade fuel.

Simply put, stay the hell away from anything lower than 87 octane. It can cause damage.

Wed Feb 05, 2014 9:49 pm

I agree that knocking with 85 octane is your problem. I didn't even know 85 octane existed

~tc~ · Thu Feb 06, 2014 1:29 am

85 is common at lower elevations

Anti-knock should kick in to eliminate the noise, but will greatly reduce power

For the <$10 it costs, I would get a can of seafoam and clean the intake, manifold, etc. beware! It can generate A LOT of smoke!

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murcod · Thu Feb 06, 2014 4:25 am

There's a CVT Kizashi near me that I've heard driving past when I've been out walking. There was the distinct sound of detonation from the engine as it accelerated away from a stop. I've got no idea what fuel they were using- especially given the Kizashi is rated to use the lowest octane fuel available in Australia!

PS: Given it's the CVT model, it might pay to look through some of the CVT related posts. I'm sure rumbling noises have been mentioned before.

peezi · Thu Feb 06, 2014 5:39 am

Thanks for the feedback everyone. I live in Denver, and 85 is the norm here.

So funny thing, my previous car was a 98 Wrangler, 325k miles. I loved to work on that car. Anyway, I opened up the hood on the Kizashi tonight while I was in the garage, and although I was very intimidated by this 21st century engine and related components, I started to mess with it like I used to with my Jeep. Anyway, tightened a few bolts, checked the fluids (transmission fluid seemed a little low, but I don't want to add Valvoline CVT fluid to it unless I'm sure its OK to do so, thoughts?), you know the easy stuff that pretty much anyone can do. Well, I took off that big black thing on top of the engine that makes the engine look cool, didn't even know it would come off so easily. I was in a hurry to pick up the air filters I bought for the car so I took off and left that piece (engine cover that really seems like its just in the way?) behind. Well, I tried to get the rumbling to occur again, but I could not.

So now I'm thinking it was that engine cover rattling around, has anyone ever heard of this happening?

I suppose I should put the cover back on later and see if I hear the rumbling again. Does this cover do anything???

LPSISRL · Thu Feb 06, 2014 3:16 pm

I think 85 octane is for higher elevations. Higer altitude, thinner air. Thinner air, lower compression. Lower compression, lower octane required. So becuase of the high altitudes in CO, you see 85 octane more common. I'd still use 87. There's no way I could see that it would hurt anything.

LPSISRL · Thu Feb 06, 2014 3:26 pm

It does sound like pinging. However, pinging does not really sound like a rumble. More like marbles in your exhaust system. But you'll get it under moderate to hard acceleration when engine spark timing increase more. However, sometimes under hard acceleration, you won't hear it as engine noise and such may drown it out. The coming and going coud be coinciding with the octane rating of the fuel you're using or maybe if your at the edge of pinging, the barametric pressure could even be comng into play here. If you drove at lower elevations with the 85 octane fuel and it got worse, you'd know for sure.

SamirD · Thu Feb 06, 2014 5:13 pm

I'd check your oil levels if you haven't already. I notice that there's a lot of valvetrain noise on mine (not sure if this is normal), and I know this can be caused by just a little too low (or high) oil level.

smsmart · Thu Feb 06, 2014 6:06 pm

LPSISRL wrote:I think 85 octane is for higher elevations. Higer altitude, thinner air. Thinner air, lower compression. Lower compression, lower octane required. So becuase of the high altitudes in CO, you see 85 octane more common. I'd still use 87. There's no way I could see that it would hurt anything.

LPSISRL is right about this...I used to live in Colorado too and 85 octane is the standard grade due to the elevation (Denver is at 5280 ft/~1609m) and therefore thinner air. So basically all of the grades (regular, super, premium) are notched down an octane or two from the usual level that you would see in other parts of the country.

So 85 should work fine given the conditions. If it really is a pinging issue (i.e. the marbles in a can noise when accelerating), then it may just be the car and not necessarily the fuel. For example, I live in San Diego (elevation = sea level), and started experiencing the pinging myself, even though I was using the recommended 87 octane fuel. So I went ahead and started using super grade (89 octane around here), and so far the pinging seems to have stopped.

So in my particular case, I think the car just doesn't like regular gas, PERIOD. Either that, or maybe it was crappy gas to begin with

Regardless, I think the 85/87 octane difference is irrelevant. Just use the next grade up if you're having pinging issues.

peezi wrote:So now I'm thinking it was that engine cover rattling around, has anyone ever heard of this happening?

I suppose I should put the cover back on later and see if I hear the rumbling again. Does this cover do anything???

It might aid in reducing audible engine noise and heat transfer, but aside from that...don't know. It could very well be the engine cover though. Given how much the engine in the Kizashi vibrates, it's very well possible that the cover is bumping up against something from time to time. I know in my car I have mysterious intermittent engine rattles that are audible in the cabin, and my suspicion is that something is just bumping up against something else--could very well be the cover! I haven't tried driving around without it yet.

Also, I've noticed in my Kiz that the exhaust pipes in the back of the car also have a little bit of a rumble. In my case it's a nice little purrr, but maybe it's more pronounced and intermittent in yours?