Author Topic: K75 engine squeaking (Read 7110 times)

andrej_gr · « **on:** October 08, 2019, 05:05:30 AM »

Squeaking noise suddenly started coming out of my engine on my way home. It disappeared after a few kms then reappeared, then disappeared again.
There is enough oil and oil pressure bulb goes down as expected.

This can't be good... Any ideas?

daveson · « **Reply #1 on:** October 08, 2019, 05:35:02 AM »

Listen from many different points to try locate the source. Does it change with the clutch pulled, or something like that?

Martin · « **Reply #2 on:** October 08, 2019, 06:55:33 AM »

As per Daveson either use a large long handle screwdriver as a stethoscope or buy an automotive stethoscope. They are relatively cheap and a worthwhile addition.
Regards Martin.

johnny · « **Reply #3 on:** October 08, 2019, 07:01:31 AM »

fore pin

Laitch · « **Reply #4 on:** October 08, 2019, 07:38:24 AM »

Quote from: andrej_gr on October 08, 2019, 05:05:30 AM

This can't be good... any ideas.

First, consider being more hopeful and less dramatic. :-)

Follow daveson's and Martin's suggestions. It could be an alternator bearing or loose mechanical connection within it—you've been in that assembly once already—so check that with your screwdriver.
Open the fuel cap while this noise is happening; the fuel pump could be making it.
Always verify, as j o has indicated, that the pump's electrical connector is making full contact and current is not dropping out intermittently.
Include your moto's year in your Signature, too so it will show up under every post you make and respondents won't need to backtrack to learn it. Parts can differ from year to year.
Walk your cat around it to see if it is attracted to a gerbil, mouse or pygmy possum nest. Engine operation might be disturbing the young.

volador · « **Reply #5 on:** October 08, 2019, 12:08:29 PM »

Sounds like the water pump

Laitch · « **Reply #6 on:** October 08, 2019, 01:01:07 PM »

Quote from: volador on October 08, 2019, 12:08:29 PM

Sounds like the water pump

I've seen them leak but haven't heard them squeak. If the noise is coming from a squeaking but not leaking combo pump, I'd flush the cooling system and refill with high quality, nitrite-free, long-life coolant. The lubricant additives in it could eliminate that noise.

His screwdriver stethoscope should locate that easily.

Chaos · « **Reply #7 on:** October 08, 2019, 01:44:23 PM »

I'd guess fan belt. To bad you don't have one.

daveson · « **Reply #8 on:** October 08, 2019, 05:54:55 PM »

"fan belt" Good one Chaos. I fought hard to resist the urge to say that.

Scott_ · « **Reply #9 on:** October 08, 2019, 06:27:42 PM »

I'd also check the radiator fan motor.....the bearings can squeak before they seize up.

-mek- · « **Reply #10 on:** August 31, 2020, 05:08:41 AM »

Hi Andrej,

Did you found the reason for that squek? Mine squeks just like yours, only in idle when hot. Not when cold. I repaired waterpump last winter, replacing all the seals and also the shaft, because it was also worn under the wet side seal. I've just done about 1700 kms after the water pump repair and now it started squeking on idle when hot. I tried the screwdriver methond and the squeak seems to come from water pump. I'll have to open it again.

Cheers,
Markku

daveson · « **Reply #11 on:** August 31, 2020, 05:54:29 AM »

Don't hold your breath, Andre hasn't logged on this year.

One old school trick that sometimes worked was to add a cap of cutting oil to the coolant. It's a fair surface area of seal so a bit of lube can help, never opened a BMW K pump tho.

Laitch · « **Reply #12 on:** August 31, 2020, 10:59:05 AM »

Quote from: -mek- on August 31, 2020, 05:08:41 AM

I've just done about 1700 kms after the water pump repair and now it started squeking on idle when hot.

Was the timing chain replaced during your renovation? Did you use the screwdriver at points across the timing chain cover? One owner indicated a worn timing chain started to contact the cover below the shaft seal. He didn't mention a noise but I'd expect that if there was a noise, it would likely be amplified in the timing chain assembly space and audible when idling.

-mek- · « **Reply #13 on:** August 31, 2020, 02:59:14 PM »

Timing chain and sliders has been done about ten years ago at ca. 78 000 km, now 133 000.

-mek- · « **Reply #14 on:** September 03, 2020, 12:29:16 AM »

Andrej answered my pm and said the squeak of his bike disappeared when he cleaned the fuel pump connector. I tried it first, but it (naturally) had no effect on squeaking. I even tried it with fuel pump connector of rotating engine with starter, could hear the squeak.

My friend lent me his stetoscope yesterday. The squeak seems to come from water/oil pump, so coolant out and pump off again.

Laitch · « **Reply #15 on:** September 03, 2020, 11:27:55 AM »

Thanks for the update, mek. Restoring one of these pumps often takes a second try. The squeak is an uncommon problem. Please keep us posted.

-mek- · « **Reply #16 on:** September 03, 2020, 12:59:26 PM »

Overhauling the pump required a second try also for me, in last winter. Wet side seal is tricky to install. I allready took of the pump cover and impeller. Both vere fine, impeller didn't scratch anything and the wet side seal seems to be ok. Tomorrow I'll remove the pump and see the gears behind. Let's keep fingers crossed the problem is in pump gears. Because, what's behind... output shaft :-(

-mek- · « **Reply #17 on:** September 06, 2020, 01:27:32 PM »

I unassembled the water-/oil pump. I cannot found a clear reason for the squeaking sound. Pump does not leak, neither oil or coolant. Both seels look fine. Impeller was still a bit stiff to turn by hand. Some marks can be seen on impeller shaft gearing and oilpump case. I would doubt for some othe part to be broken, if the squeaking sound wouldn't so clearly come from water pump cover.

When I listened with a stetoscope with metal pick, the highest sound came from water pump cover, next highest from water pump case. From Timing chain cover or motor block the squeak was hardly hearable.

stokester · « **Reply #18 on:** September 06, 2020, 07:06:12 PM »

Thanks for the update MEK.
I, like many have had to do multiple water pump rebuilds and wish to know the source of your squeak.

Laitch · « **Reply #19 on:** September 06, 2020, 09:25:07 PM »

I wonder if this mark was made before the pump's recent disassembly.

squeak source?.jpg (90.43 kB . 768x576 - viewed 622 times)

-mek- · « **Reply #20 on:** October 16, 2020, 01:34:44 AM »

After thinking the problem my quess is, that the water seal is very difficult to assemble right without the BMW special tool. The pump is made from aluminium and the shaft from steel, so the pump expands more in heat than the shaft. Thus the seal gets more tight when the engine heats up. In my case it caused the squeak. I sent the pump for repair to http://www.equipmentbau.de/index2.html and got it back wery quick. Now it works ok.

Laitch · « **Reply #21 on:** October 16, 2020, 12:07:28 PM »

Quote from: -mek- on October 16, 2020, 01:34:44 AM

After thinking the problem my quess is, that the water seal is very difficult to assemble right without the BMW special tool.

Plenty of posts here support your observation, mek. Still, many owners have successfully managed the task without it although it might have taken some of them a couple of attempts.

If I were in Finland, I'd have done what you did to insure i could get more riding time on the moto in your beautiful country during its short riding season. I hope you will post more photos of your travels in the Photographic Ride Reports section occasionally.

News:

Author Topic: K75 engine squeaking (Read 7110 times)