Pool Pump Turns On, Makes Loud Noise, Then Cuts Off

[RoberTX]

Hi,

When I turn on my pool pump, it makes a very loud vibrating / grinding noise for a few seconds and shuts off. It has been making a grinding noise at startup for as long as I've had this house/pool; over one year. It was also probably louder than normal while running after startup, but this is the only pool I have any experience with, so I am not sure.

Info on pump:

Looking at the pump motor, I noticed a cap was loose, so I took it off and it had grease in it. This is probably not normal...

I should also probably mention that my concrete pad is in terrible shape. This is could be causing vibration issues, but the pump seems to be pretty stable (when trying to shake/move it).

I've just started to do my own research online, but I don't have much time to take action since I don't want to go without a working pump for more than a few days.

I am looking for any advice about what could be wrong with my pump and what my options may be. As far as I can tell, my options are:

1. Repair the pump motor myself
2. Replace the pump motor myself
3. Pay someone to repair the pump motor
4. Pay someone to replace the pump motor
5. Replace the entire pump myself
6. Pay someone to replace the entire pump

I have heard that 2-speed pumps could potentially save a lot of electricity, so I'd like to consider that option.

Please help me get this fixed so my pool can continue to look like this! I know it won't for long without circulation/filtering in this Texas heat!

Thanks,
Robert

 

[Bama Rambler]

If you have an electric motor shop close that's probably your quickest fix. It probably won't be terribly expensive either. All you'll have to do is take the pump out and get it there.

 

[RoberTX]

UPDATE: After leaving the pump off for about an hour, I was able to turn it back on. Again, it made a very loud noise at startup for about 5 seconds. I can see the motor shaft that drives the impeller, and it doesn't spin when first powered up. It starts to spin when the noise stops.

Also, thanks for the electric motor shop tip, I'm going to look into that.

Still looking for any other inputs on what may be causing the problem and advise on whether to repair or replace.

Robert

 

[Bama Rambler]

can you turn the shaft manually with the power off?

It's most likely the bearings. The motor shop will be able to tell you if it's repairable or not.

 

[maxepr1]

Rober, let me know how it works out! I tried some motor shops in our area and they want a kings ransom to replace bearings and clean! I think the cheapest price I got was $109 and they were a week out back in april!

 

[RoberTX]

Here is a video to illustrate the noise. It sounds louder and worse in person.

http://www.youtube.com/watch?v=FlWns5Ru7Fk

In the video, the pool pump electric motor starts 'normally' the first time. Second start is very loud for about 5 seconds and then runs. Note that the motor shaft can be seen clearly and does not move during the loud 5 second start. After the shaft starts spinning, the motor is much quieter and drives the pump well. If the motor is shutoff while hot, and then a restart is attempted, the thermal protection shuts it off and it has to cool down before another start can be attempted.

Robert

 

[maxepr1]

Sounds nice! Have you taken the cover off the start capacitor? Looked to see if it's bulging on the ends?

 

[RoberTX]

I plan on testing the capacitor with an analog meter tomorrow morning. I hope that's it!

 

[maxepr1]

Sounds like bearings too, but it's having problems staying started? Sounds just like an AC unit when the start capacitor is bad?

 

[RoberTX]

I forgot to mention that the motor shaft is easy to spin by hand. Well, I'm off to test the capacitor. If it's good, I'll be removing the motor...

 

[RoberTX]

The capacitor checked good. I used an analog multimeter on the Resistance (Ohms) setting. After discharging the capacitor (shorting the terminals with a screwdriver or a test lead), it read 50 kOhms and then quickly decayed to a very high resistance. I repeated this several times: discharge again, measure resistance. I expected a lower initial resistance, but I have a very cheap multimeter, so who knows...

I'm fairly confident the capacitor is good, since I would expect it to be failed completely open or shorted, and it is not. It definitely pulls some current initially when discharged, and then reads open until it is discharged again.

The capacitor looked almost new. Here's a wonderful picture.

 

[RoberTX]

OK. Took the motor off, took it to a shop. It would cost more to repair it than it's worth. The impeller is in bad shape and the motor housing is worn, metal dust in housing, etc... I'm convinced the best thing to do is to replace the entire pump. For now I have reinstalled the motor and it is limping along (actually works pretty good as long as it starts.

As long as this pump continues to limp along, I will have an opportunity to research pumps and pick the right one. I'll be starting a new thread for choosing a new pump.

 

[maxepr1]

Rober, 2 speed.

 

[TexasHonda]

Just joined TFP and thought I'd check "pump repair" since I just repaired mine yesterday. New bearings on both ends. It's running fine today.

Your motor looks similar to mine. I've replaced bearings, pump impellor, pump housing on this 25 yr old motor and pump and it's working fine. Here's the repair procedure (Make sure all power is isolated w/ mulitple isolations):
1) Remove motor and impellor from pump casing. Mine separates w/ a ring clamp seal, very easy. Your's looks different
2) Remove pump impellor from motor drive shaft. From motor far end restrain shaft from turning w/ vise grip or open end wrench. I grip the impellor small end w/ a rubber strap wrench. A large set of slip-jaw pliers will work also. Check youtube videos for this stage.
3) Remove pump end from motor end. On mine 4-nuts retain pump end to motor.
4) Remove two screws on motor end assembly near motor shaft. These hold a retainer plate on the motor pump end bearing.
5) Remove pump end of motor. This part is tricky and key to the repair. There are 4 long through-motor-body bolts (~ 3/16"x12" long) that run from motor far end into motor pump end. They are likely to be tight or frozen and not release (don't force them and twist off!). If they won't turn, I suggest grinding the heads off. This will allow the bolts to pull through motor body w/ pump end and ease removal from motor end. You will need replacement long bolts from a bolt specialty store. I can see these long bolt head ends in the picture of your motor rear end. Once you have the motor end loose, suggest using propane torch to heat the pump end and allow vise grips to turn the bolt end. Worst case, have a machine shop drill out and install inserts.
6) Pull motor rotor shaft out of motor housing. It will pull out towards the pump end.
7) Clamp rotor shaft in vise and use 3-leg gear puller to pull old bearings. You will need to clean, polish, and lube the motor shaft to ease bearing pulls.
8) Tap new bearing in place w/ socket on motor shaft rear end. Pump end travel is too long to use a socket. I use a brass piece and lightly tap on opposite sides to drive/seat the bearing on the shaft.
9) Reverse disassembly to complete. IMPORTANT for future repairs is to put a good coating of anti-sieze on the long bolt threads to ease future removals. I only have 3 long bolts holding my motor together. Very little load on these bolts other than preload of tightening. Don't overtighten, just snug.

PM me w/ any questions.

good luck