Mini van ocasionally sounds like motorcycle

kia
sedona

#1

Our mini van (2003 Kia Sedona) occasionally sounds like a motorcycle is revving to pass it up. Sometimes it will go for weeks without doing it and sometimes it will do it several times within the space of a few hours. Doesn’t seem to have any connection to speed (most of our driving is in the 35-55 mph range with occasional 65 on the interstate) What in the word can cause this???


#2

Well, at the moment it would be hard to say what “this” is - and so impossible to say what the cause might be.

You’re going to need to get more descriptive both about the sound and about the conditions under which it occurs - e.g. while accelerating, decelerating, just cruising, any of the above? Van hot or cold or either? Any braking involved? How long does the sound last? Where does it seem to come from? A passing motorcycle gives the Doppler effect - changes in pitch as it goes by. Does yours?

Is there a check engine light on?

Does the van have a tachometer (the rpm meter) and does the tachometer do anything odd at this point?


#3

Yes, there is a change in the pitch. It really sounds just like a motorcycle (not a big Harley, medium sized bike) is passing us by. We actually thought that was what it was the first few times. Usually just lasts a few seconds… long enough for a motorcycle to pasy by a vehicle.

There is really no pattern to when it happens. Accelerating, decelerating, just cruising… all of the above. Van hot or cold? Both. It can happen as soon as we pull out of our driveway (onto a 20 mph street) or when we are on the main road to tow (45 mph) It can happen when you are pulling away from a traffic light or stop sign or happen when you are driving at a steady pace down the road. I have never looked at the tach. Will try to remember to do that next time it happens. No check engine light.


#4

I have a 2004 Kia Sedona with exactly this strange effect. It is quite strange since it sounds exactly like an accelerating motorcycle in the adjacent lane. It happens at a very intermittent rate, maybe once per week or month. I hear it when I am not braking, but usually driving 40 MPH or faster. The unique characteristic of this is a modulated noise, where the modulating frequency ramps up over about 3 seconds. The modulating frequency starts at somthing low (like 3 Hz) and goes to something higher (like 10 Hz)- sounding like a motorcycle going faster and faster. The effect is so convincing that I still look out the window for the lunatic motorcycle driver. I’ve noticed this over the whole life of the vehicle (now 110k miles) and I’ve seen no correlation with belt age, or anything else obvious. I have no idea of the real cause, but I wonder if it is some sort of vibration in the exauhst system. Very strange! I’m glad to hear someone else reporting this.


#5

I can’t relate to the sound you describe since all motorcycles don’t sound the same. Can you describe the noise without comparing too a motorcycle (or any other machine?)