Sounds like a water pump going?

jtalics

New Member
I am experiencing a strange noise. At about 2000-2100 rpm before the fan kicks in, I am getting an internal (towards the forward) engine sound like a shaft is spinning and a resonance occurs... rattling, maybe a bad bearing. But when the fan kicks on, that sound completely disappears and the engine is as smooth as day one. Any ideas?

2006 FZ1-s
 
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Rooster

New Member
If your water pump was going, it would be highly likely that you would see coolant coming out of the coolant weep hole, which is located toward the back of the oil pan (the exhaust etc makes it hard to see under there...use a torch).
This is a good indication that the seals (and possibly the bearings) on the oil/water pump impeller/drive shaft have failed OR are failing.

WHY?
The oil/water pump uses the same impeller/drive shaft and the seals on that shaft stop the oil and water from contaminating each other.

Another indication of coolant leaking from the weep hole is....you'll smell what i would call a sweet or odd odour (definately not an oil smell) after turning the bike off.
The weep hole is positioned so the leaking coolant drops onto the exhaust and burns off (hence the smell after shutting the motor off).
You can smell it by just sitting on your bike after turning it off as the "odour" will be coming from basically directly beneath you and it wont take long for you to get a woft of it.

If there are no signs of a leak from the coolant weep hole or any strange odours after shutting your bike off, it probably isnt your oil/water pump.

By the way...which fan is kicking in at 2000-2100rpm?
If its the cooling fan/s for the radiator, they are only operating because the motor has reached its pre-determined Hi-temperature setting before the ECU activates it.

The fan doesnt kick in based on the bikes RPM (im sure you know that) so i hope that isnt happening.

Is your motor running HOT all the time?

Its strange that the noise dissapears upon activation of the fan...there's definately something querky going on there.
 

jtalics

New Member
Thanks Rooster for the thoughtful and clear help. I don't see any coolant or smell anything strange. So that is a relief that it is probably not a water pump going. I am going to conclude that is some strange resonance going on not worry about it.

Sorry, I wasn't clear about the the rpm. At RPM of 2000-2100 I get the noise until the radiator fans start at 214 degF. I didn't mean to imply the rpm is controlling the fans -- they kick on only because the temp got to 214F.

Motor is not running hot.
 

Rooster

New Member
Youre most welcome jtalics, im happy that i could share some insight into the potential problem.

You may be right, it could well be a resonance issue.

ALTHOUGH, the fact that your noise or resonance dissapears when the cooling fans kick in is really strange.

I'd love to know what's causing it to be honest....if i come across anything i'll let you know.
 

jtalics

New Member
The 2006 FZ1 has an analogue tach, which might have a cable running to it. This would explain the RPM dependence, but not the fan dependence. I wonder whether a thermostat opens as the fan starts. Maybe the circulating water would interact with the tach cable as it enters the engine (if that is indeed the design). Curious!
 

jtalics

New Member
My fan kicks on at 214 degF, but the thermostat uses a bimetallic to start opening at 160F and is fully open at 185F according to the shop manual. So it appears that the water flow has nothing to do with my sound. Also, the tach is electric and there is no mechanical cable.
 

jtalics

New Member
Update! The RPM range on the "resonantion" is now 1000-1800 and the rattling/grinding sound does not go away when the fan comes on. A failure may be imminent, stay tuned as we get to the bottom of this.
 

jtalics

New Member
If the problem and sound is in the generator, then that could explain the (now defunct) fan-dependence. When the fan kicks on, it pulls a current which changes the load on the generator.
 
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