Squealing and whining squirrels under my tank!!

[The Velvet Monkey]

I'm getting a squealing or whining from something "up front" on the bike. It starts as soon as I turn over the key and continues after starting the engine and sounds as if it's coming from the area of the alternator belt (which checks out okay) or under the tank. Sometimes it stops whining when I apply the brakes, sometimes not.

If anyone has a diagnosis, I'd love to hear it. I've got an appointment this weekend with the dealer for a brake service and I'd love to have at least a clue as to what it might be. My guesses--fuel pump or ABS pump/servo.

Thanks to all who reply.

[towerworker]

"My guesses--fuel pump or ABS pump/servo."

I think you have it. Those are the only two devices that would make the sound you describe. Question though----any ABS fault lights on? How long has it been making noises? The abs servo assembly makes several noises and they vary with brake pressure and so on. The fuel pump should make some noise as the switch is turned on and then go off prior to engine start. It then turns back on as the engine starts and runs continuous but you should really not hear it much if at all while the engine is running.

Wayne

[Airman]

"My guesses--fuel pump or ABS pump/servo."

I think you have it. Those are the only two devices that would make the sound you describe. Question though----any ABS fault lights on? How long has it been making noises? The abs servo assembly makes several noises and they vary with brake pressure and so on. The fuel pump should make some noise as the switch is turned on and then go off prior to engine start. It then turns back on as the engine starts and runs continuous but you should really not hear it much if at all while the engine is running.

Wayne

Yeah,
If it's the brake servo, it will make the noise without the engine running. Same with the fuel pump.

[The Velvet Monkey]

Thanks for your input, Wayne.

No ABS fault lights, so far, and she runs like a raped ape--I commute about a hundred miles a day and no issues other than the sound, which it's been making for about two days.

Go figure, huh?

[boxermania]

Mr. Monkey

I see it as one of two possibilities

1) You do have one of those furry friends under your tank...
2) Maybe the alternator bearing is going out......mind you, I have never heard that mentioned on this or any other BMW forum.

So, I have to go with the fuel pump.....is the squealing more noticeable with low fuel level in the tank?

Please realize that my diagnosis is tantamount to finding what hurts based on the smell of perirectal wind.....besides, I don't know if your species is akin to this type release....Velvet and all.......

[Sunbeemer]

I'd guess (and that's all it is) is it is related to your ABS brake servo unit since you mentioned it sometimes goes away when you apply the brakes. Perhaps that's just coincidental...but maybe not. I think it's good you're taking it in for brake service at this time. BTW, I don't have ABS so I know nothing about them or I'd beam down there and try to help you sleuth it out.

[wjjones]

I have the same sound but I can rule out ABS because my bike doesn't have it. I don't think it's the fuel pump because it sounds like it is outside an in front of the tank. I would describe it as a chirping/squeaking sound. It only lasts until the engine warms up.

I'm waiting for more clues from you guys--thanks!

[sweatmark]

So what's the answer to diagnosis with ignition switched on, but motor not yet started... squealing? Or does the sound occur only with motor running?

[wjjones]

I should have read the original post more closely. I didn't realize the sounds would start before the bike was running.

[Beemeridian]

11

[The Velvet Monkey]

Well, for what it's worth, here's what happened to the squirrels.

When I brought the bike in (to Haps Cycles, Sarasota), I clicked over the key to the start position the squealing started for the service manager, who coincidentally rides a Rockster. He immediately said the sound was coming from the fuel pump and asked whether I had replaced the fuel filter (bike's got 26k on the clock). I told him that I just bought one that I intended to install as soon as I got the bike back from them. He said the R's will sometimes squeal when the filter reaches the end of its usable life and that I should replace it ASAP.

Interestingly, however, when I picked the bike up--I had my annual brake service done and the brakes checked out okay--the squealing was gone. I replaced the fuel filter this past weekend and it hasn't returned. Maybe the whole squealing was due to my QDs (mine are the Small Parts brass versions and the mechanic annihilated one them trying to get re-attached--a problem with the Small Parts version, although it had never happened to me before).

Go figure? Evidently, the fuel pump is sensitive to dirty filters. Beware!