Droning/whining noise at 30mph

[matt185]

Hi everyone

Just bought an immaculate 03 HRV non VTECH Manual with 29K on the clock. Inside and outside look as new and I've been delighted. However, despite trying to ignore it, as soon as you hit 30mph, a medium pitched whine/droning noise starts - disappears again at about 40mph. Noise is there if you depress the clutch too so I'm not sure what that suggests. Tyres all appear to be the same size and it had its 36 AND 45K service in March 08 according to the service history with no apparent problems. Could it be rear diff fluid needs replacing? I'm v non-mechanically minded but it has been mentioned in other similar threads - more CRV though (which I also own - hasn't missed a beat in 5 years - best car I've ever owned!) Any help much appreciated - still have 2 months warranty left from the dealership (non Honda) I bought it from although reading it, they seem to exclude almost everything you might find on a car!

Many thanks all

Matt

[Racoon]

Do the 'parking lot test' to see if it's the rear differential, although from what you describe I don't think it's the rear diff fluid.

Also, try rotating the tires to see if the noise changes or goes away.

Welcome to HondaSUV.com!

[matt185]

Hi - thanks for the speedy reply and welcome!

What's the parking lot test?! I've noticed on full lock left or right, there's a bit of a buzzing sound???

Cheers

Matt

[Racoon]

Originally Posted by matt185

What's the parking lot test?! I've noticed on full lock left or right, there's a bit of a buzzing sound???

1. Find an empty parking lot.
2. Open the drivers side window and stick your head out.
3. Drive slowly in a tight left turn and listen for noises from the rear end.

A moaning/groaning/rumbling sound from the rear end means you need to change the rear differential fluid, assuming of course you have RT4WD.

But unless the fluid has been severely abused, it's not likely that a "medium pitched whine/droning noise" while driving in a straight line is a rear diff problem, unless your tires are different sizes. And if they were different sizes you'd hear the noise most of the time.

The RT4WD system is pretty particular about tire sizes, so even if you have four tires that are marked as being the same size, unless they're the same manufacturer and exact same model they may not be exactly the same size. There is some flexibility in the RT4WD system, but any tires that are more than 3-4% different in circumference may cause problems.

[Rue2003]

Hi Matt,
I appear to have the exact same problem on our 2005 VTEC1.6 manual that we have had for just 2 weeks. My local independant garage cannot find anything wrong with wheel bearings or propshaft and the car park test yielded no noises. They have suggested it might be tyre noise - it is fitted with 205x60x16 Michelin Energy Savers all round which look quite new (I presume this is the correct tyre size). I'm not sure if the 'wheel bearing hum' noise dissappears above 40mph or is just drowned out by general background noise(engine etc) but it definitely starts at 30mph. I'm taking it to a Honda specialist today to see what he thinks but really appreciate any feedback you have on your problem.
Cheers
Rupert

[mrtn]

welcome. yes, the size is correct and thse energy savers shouldn't make any excess noise. does it hum in straight line as well?

[Rue2003]

Hi,
thanks for the welcome and speedy reply.

Yes, it hums in a straight line and on varying quality of road surfaces. I have ruled out wind noise from the roof spoiler has it only happens at 30 mph and by 40mph appears to go away - v. strange!

['Curly Q Links']

Originally Posted by Racoon

1. Find an empty parking lot.
2. Open the drivers side window and stick your head out.
3. Drive slowly in a tight left turn and listen for noises from the rear end.

Actually, the Parking Lot Test works better with the window UP since you're listening for a low frequency grind / vibration. Noises in the street just distract. Also, don't expect to hear it from the REAR because it often sounds like it's coming from under the hood. The whole drive train 'comes alive' and the hood seems to act like a sounding board. If it's really bad you may feel it through the floor and steering wheel too. Be careful not to hold the wheel tightly at 'lock' because you'll get noises from the power steering that will confuse the issue.

I've probably done it at least 20 times (different Hondas) and that's my observation.

[matt185]

Hi Rupert

This appears to be a known problem and it is the rear diff. One thing they try is to replace the rear diff fluid. In fact they do it 3 times. Replace it, drive it, let it cool, empty and refill! Anyway - annoyingly that didn't work for me. Uneven tyre pressure makes it noisier but equal pressure doesn't fix it. Mine has only done 35K so it seems ridiculous that a rear diff can develop a fault after so little mileage. The last service confirmed it was rear diff whine. Trouble is, once you know it's there it drives you mad. And it seems in rush hour, you're always stuck at 30mph when it kicks in. So - sorry I can't solve the problem. I'll be interested to hear what your Honda specialists say. No idea how much a new rear diff is in the UK either but that may be the only fix.

Cheers

Matt

[CRX]

I'll be amazed if it is the rear diff unit, and if you do ever get around to replacing it, I want the old one. (I'll pay shipping etc)

Try removing the main drive shaft and see if the noise goes. (Carrier bearing?)

Did you rotate the tires (front to back)?

(-&