I am at my wits end with a noise that comes from the engine/front area of my 1988 Acura Legend (sedan). The noise does does not change with the engine rpm, is definitely not from the suspension, only shows up when the car is moving (as in, I can rev the engine when the car is stationary, and the noise is not present) and is not constant (as in, it is loud and clear sometimes, but is not constant). Short of strapping someone to the front-end, I could not for the life of me figure out what this noise is, and decided to strap the next best thing … a phone to record the noise.
Here’s a Dropbox link for the recorded sound: Link
The noise can be heard at around the 20 second mark. There are other squeaks and rattles (the phone is in the engine compartment, so …), but you’ll notice that the squeak/screech comes on and disappears.
Any help or hint (even steps to troubleshoot this noise), would be much appreciated. Thank you folks!
Appreciate the super quick response and completely understand the hesitation to open a random Dropbox link.
I have taken the wheels off and the brake dust/shield is definitely not an issue (I loved the rock theory though, because I hadn’t thought of that myself). Same with the driveline parts, this noise started a while back, and since then I have changed both the front half-axles (unrelated to the noise, the CV boots were broken and one side was making the dreaded clicking noise).
I don’t know how to precisely describe the noise, but to me it seems similar to a a belt/tensioner sort of noise.
Is there any chance that the soundcloud link below might be safer? Or if you have a suggestion for a place that might be, I’d be happy to upload there? I really think hearing the noise might offer a clue.
I’ve listened to the file. It’s at a steady frequency, not related to rpm’s or speed of vehicle. It’s like a fan hitting something with one blade intermittently. It’s kinda a metal hitting metal sound.
OP. Is Your heater fan on during the recording?
I don’t think it is the heater fan, but I can’t think of anything else being able to make that sound so distinct. Not even the radiator fan. Well, check that anyway.
Please respond back with what You find.
All very good suggestions, thank you.
Unfortunately, I can guarantee that it’s not the wheel bearings (a mix of a growl + hum sound that I am familiar with), nor the brake pads (I know the sound you are referring to here as well). I have done quite a bit of front-end work on this car, so I hope this doesn’t come across as my rejecting your advice/being flippant.
Ah! the fan hitting something intermittently is a very good idea to check.
Just to be clear, when you say heater fan, did you mean the HVAC blower motor? I did replace that motor a couple of weeks back because it actually burnt out (and hence unrelated to this particular sound, but photo attached for clarity). But I presume that you meant something like the radiator fan (there are 2!)? Also, just to be clear, I strapped on the phone (used to record the sound) in the engine compartment/under the bonnet and then drove the car around the block.
Ummph, the HVAC motor (whatever that means) is a heater fan. Bear with me, a spade is not a dirt mover, it’s a spade.
The circumstances indicates that the problem is that one of the radiator fans could be the culprit, but only You can clarify if any of those were activated during the recording.
You can do a simple check.
With the engine OFF, grab the the fan and wiggle it. If any of them can be wiggled, there’s Your problem, I think.
Geeez. I might be considered an old farth, but ain’t that a just a way to make something simple, difficult.
I like KISS, but I GTTINGE.
(guess that, that is not good enough)
Spent some time trying to nail this down, and based on the collective advice, tried out the following:
a. Visually inspected and wiggled the two fans up front. There is no slack, and there are no visual signs of damage to the fan blades or the radiator shroud.
b. The car has handy fuses for the condensor and the cooling fan. I removed one at a time to see if the noise went away. It didn’t.
c. Since the noise happens only with the car in motion, I went to an empty parking lot and tried going forwards as well as backwards. The noise occurs in both cases.
d. This car has a manual transmission, so I wanted to check if this was happening when the transmission was engaged or not. Heard the noise both in gear and coasting with the clutch depressed.
e. Ensured that the heater fan was not turned on either.
Anything else that comes to mind for you folks?
In case it helps, I strapped my phone to the engine and got another recording.
Not the heaterfan, not the radiatorfans. WHAT is rotating in a 1988 Acura Legend independently of engine and vehicle speed - as long as it is moving?
This might be the most stupid question ever asked:
Does it have an electrically operated smogpump?
It’s gotta be something simple.
Suggestion: Borrow Your neighbours son and strap him to something solid in the engine bay and drive around on an empty parking lot.
That’s probably best done at night time.
Btw. Did electrically assisted power steering exist back then?
Thanks again for the suggestion, at this point, just about any question is a good question. I’ll have to get back to you about the smogpump (I don’t even know if this car has a smogpump, and Google doesn’t seem to be much help, I’ll pour through the repair manual).
Precisely why I am so annoyed with this too. I even jacked up the car on each side and rotated the wheels by hand and checked to see if there was something like a wheel well shroud/cover loose or not… nope!
Might have to do this.
This particular car has a hydraulic power steering.
Support the drive wheels safely with jack stands in the air, disable stability control, have someone put it in drive and reverse. With wheels spinning, use your stethoscope and isolate area. Be sure assistant uses brakes to stop wheels before putting in park and don’t need to go over 40 an speedometer.
Thank you for this suggestion, this seems like a really good way to troubleshoot this issue.
I’ll have to wait till next weekend to attempt this (since I’ll need help), but I will report back on the findings ASAP.
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