Mysterious clunk - GreenHybrid

daddywags · #1 (**permalink**) 06-01-2005, 06:01 PM

I start my HAH in the morning and back out of the garage. When I then shift into drive and start forward I usually hear a "clunk" after moving from 5 to 25 feet or so. It sounds like it comes from under the hood. If you have the radio on you would miss it. It only does it after the car has been sitting all night. So basically it only does it once per day. Just curious if this is normal. Has anyone else noticed this?

Rich

Tink · #2 (**permalink**) 06-01-2005, 06:17 PM

Rich,
It is normal. I also have the "Honda Clunk" as described - on both my HAH and our '05 Odyssey. I've heard many others speak of it, too. No worries.

Viet · #3 (**permalink**) 06-01-2005, 07:17 PM

Same to my HAH. It self-checks something (ABS or else).

rigger · #4 (**permalink**) 06-01-2005, 08:10 PM

I've heard of Insight and HCH owners mention a brake pad "shift" when you shift the car into reverse. It may be the same thing.

jimbob · #5 (**permalink**) 06-02-2005, 02:30 AM

I haven't heard it on my HCH yet, but I usually have the radio on. (Why have the radio on when I should be enjoying the silence? Years of habit, I guess. I never heard it on my '03 Civic either, I suppose for the same reason.) However, I have heard it on my wife's '03 CR-V and asked about it early on; the maintenance guy at my dealer said it was normal, that the brakes were re-setting. Hope this helps.

GreenAndBlue · #6 (**permalink**) 06-02-2005, 07:58 AM

Viet was right - it's the ABS self-check routine. Activates at 7mph. Present on all Accords w/ ABS (and probably all Hondas with ABS; Tink's post seems to substantiate that w/ his Ody). System was present at least as far back as the 6th-gen Accord; I had it on my coupe, but never actually heard it until the other day in this car.

Was actually going to post this last night, but the 'Furry Green Monster' ate my post (again)

, and I figured I'd just consider the issue 'resolved'. Then I saw more responses, and figured I'd provide confirmation to the group, rather than see more people guess as to the cause (as if I were a Honda engineer, or something...)

merlin180 · #7 (**permalink**) 06-02-2005, 08:36 AM

>>> Viet was right - it's the ABS self-check routine. Activates at 7mph.

Hadn't noticed the clunk but I usually have the radio on so will try to remember to look/listen for it

Slightly related......

I notice the first use of the brakes (after standing outside overnight) snatch prety violently - passengers have commented on it as well (blaming it my driving skills !

)

After the first "snatch" it settles down to it's normal level- still a bit over sensitive for my tastes but I guess I'll have to get used to it (unless someone has suggestions for that too

)

Since my parking spot is very close to the first place I have to stop, I may not have reached 7mph before using the brakes

Any thoughts anyone ?

GreenAndBlue · #8 (**permalink**) 06-02-2005, 10:01 AM

merlin180 - those are the pads themselves. I'm guessing you still have relatively few miles on your car. At first, I thought there was an overboost problem with the master cylinder, but as I put mileage on, it disappeared. It's bad, though - I'll agree w/ you there. No matter how softly you press the brake, that first stop is *really* grabby.

Honda changed their OEM pads between the 6th- and 7th-generations to a compound that will improve stopping distance - the tradeoff is what we experience. The '03s and '04s were experiencing rotor warpage / premature wear due to these pads, to the point where they issued a TSB on them - thankfully, they made some adjustments in time for the '05 run.

I don't remember when this grabby feeling (is that a word ?) went away in my car, but I think it was probably by 3000mi. Obviously, the more you use the brakes, the sooner it'll wear down and go away.

Ironically, I took the car to another Honda dealer for my most recent oil change...I got it back with 2 bars on the BAT meter (at least they didn't *charge* the pack, thankfully!), and they tried to be helpful and adjust my brakes. Guess what happened the first time I stepped on the brake pedal ?

Lasted a couple of days. I'm *really* starting to debate whether I should just do my own oil changes / tire rotations on this car...as an aside, my last oil analysis from my prior oil change didn't match the Mobil 1 0W-20 profile that Blackstone had on file... (and that the dealer said they used)...but it sure looked like Honda's 0W-20 formula...at least I didn't have to pay for that one, or give them oil that I bought

gonavy · #9 (**permalink**) 06-02-2005, 12:36 PM

Whew- you guys answered the same question I had, and a trip to the dealer about my daily 'clunk.' Additionally- does anyone else hear their electric motor when it kicks on? I can when I'm going slow enough where road noise doesn't drown it out. High frequency, kind of metallic. HF, I expect. Metallic, I didn't expect.

GreenAndBlue · #10 (**permalink**) 06-02-2005, 01:49 PM

Wow...that's a new one, and I have to say...I've never heard it (but I usually have my audio system on 100% of the time as well). I'll listen for this over the next few days.

One thing I *do* hear is a low-pitched, cyclical 'droning' sound from the engine bay at exactly 52-57mph. Any slower or faster, and you won't hear it.

It's not unique to the hybrid, because my coupe had it as well. But I'll be darned if I can figure out what it is. And here's the funniest thing - I don't think it was there the first few days I had the car, but popped up about a week or two later.