I just noticed a "grumbling" noise very similar to what the blower motor would sound like. You can only hear it inside the car with it running. Doesnt matter what gear its in (doesnt seem to change pitch when in drive and the car stopped vs having the car in park/neutral just sitting there), its almost like a blower motor sound yet the climate control is off. Ive tried turning ON the climate control, and again the pitch of the noise does not change.

If I rev the engine I cant hear the sound....I dont think it goes away, I think its just drowned out by the engine.

Outside the car you cant hear anything except the engine, even with my head up to the firewall area. Inside the car it sounds like its coming from behind the dash, or at the firewall area.

Any ideas?

Thanks.

-Chris

 

A: cabin fan motor clogged with leaves and debris--filter last replaced when?
acura says every year replace the cabin filter!!

B: ac belt tensioner failing

 

coolant circulating thru the heater core?

 

A: cabin fan wasnt running, and Ive tried it in both re-circulate and non-re-circulate just to rule it out. Interesting thing is that if I turn on the A/C, the initial "bump" and RPM drop when it kicks in actually makes the sound go away (or at least lowers the volume of it enough to not easily hear it)

B: possibly, but it seems like I can hear the sound evenly on both sides of the firewall (passenger and driver)

Would it be something that just starts on its own? We've had the car since new and Ive never noticed such noise.

I listened to it from outside the car and it almost sounds like grinding rocks.....Im deathly worried its the tranny, but the fluid is at correct level and looks fine. Poked around at the exhaust shields and nothing was loose or rattling.

-Chris

 

ac belt tensioner NEEDS to be inspected with engine running
have helper rev engine and observe action of the tensioner
smooth or jerky

Mine (01 TL) sounded like gravel when it went at ~80kmiles
could be heard outside the car clearly
had actually been diagnosed as bad at 45k, but not in warranty- so first owner didnt do it,
20kmiles later a shop changed the belts- just before sale to me- and didnt catch it then! got another 10k before I replaced it

a $5 mechanics stethascope will give instant confirmatiopn of problem or not on bearings

 

Thanks for the info.....Ill give it a look today. I suppose its quite possible since the "bump" when the AC comes on seems to calm it down temporarily.

 

Just had the wife rev the engine a few times while I was watching the idler....looked fine to me, no wobbliness, it just moved smoothly and adjusted tension nicely when the engine was under torque.

Had her shift from park to drive, then neutral then R and the engine didnt seem like it wanted to hop out from under the hood so Im thinking the motor mounts are fine too.

Also has me wondering if this noise also has something to do with the vibration that I feel at idle while in park. Thats been happening for a while, I just assumed it was a bad motor mount....but now with this grumbling noise showing up I dont know if they are related or what. Might have to bring it to a mechanic for diagnosis.

 

I would agree--this needs someone who knows the correct test procedures

motor mounts are ckd with engine being quickly revved while holding brake and different gears

tensioner looks fine to you? listen with a long screwdriver or the correct mechanics stethascope (everyone needs one) to ck bearing noise
Same test needed on revving quickly while under load -in gear- brakes on

 

When I bought my 2003 Type S last year there was a broken tab on the Engine Air filter box. Some ass put the filter in upside down then proceeded to press the top of the box and broke the tab. The air getting sucked in made a lot of noise. I found a window rod clip that seals it up well where the broken clip was. Much quieter now. It was a really strange noise when it was sucking air in through the seal around the air filter. Check and see if your air intake box for the engine is secure.

 

Its interesting you mention that, because I just checked the air filter to see if it needed to be replaced.

But I didnt manhandle the cover to get it back on....I know how it works I will re-check it though just in case. For now, Im dealing with a lack of coolant, Im actually wondering if the noise I hear is air being circulated through the system because of letting the coolant level get too low.

 

coolant doesnt get low by itself
it leaks out!!
WHERE IS THE LEAK~ fix that and move to next step
It may be a weak rad cap $10, or time for the 105 service and new water pump $1000
when the pumps inner seal goes it leaks coolant out a special weep hole on its bottem

also ck hose inside res cap is on secure,,falls off and coolant wont transfer, system doesnt work right
and report on the fan operation

parts stores loan (with refunded deposit) a pressure tester for the system
will simulate running pressure of 16 pounds and any leak should be plain
maybe a pinhole in a hose,,,just a loose clamp...
any swelling of rad hose means weak hose = replace

 

Yeah thats the interesting part....where did the coolant go.

Had the transmission replaced last winter, Im wondering if the sytem wasnt "burped" or refilled correctly by the dealer (the tranny replace was done by an Acura dealer, but that doesnt mean much).

Will see if I can locate a loaner pressure tester and give it a shot. Just parked the car to cool off and start changing out the coolant.

 

It took me 2 months to find a clip that would fit on the front headlight side of the air box to seal it up and keep the air from being sucked in. I tried using a small C clamp = didn't work then found a window rod clip when cleaning out some junk in the garage. It worked perfect. I was about to get a new box since the clip wasn't fixable. All's well now. Made an aweful sucking noise at idle.