[japgen]

My engine is running hot and I'm trying to troubleshoot the problem. I've flushed the radiator and changed the coolant, no help. Now I suspect the water pump. How can I tell if the pump is even running? Is there some way to tell if the coolant is being circulated through the system? thanks.

 

[nc_sv650]

How do you know it's running hot?

As far as checking the pump, before the engine is at full temp (but after the thermostat opens) remove the radiator cap and you should be able to see the coolant pumping through the rad. Obviously, use appropriate caution doing this, as the coolant is hot and under some pressure when the engine is warmed up.

 

[andyauger]

How hot?

Are you sure it's overheating? What temperatures are you running and is the fan kicking on and staying on? The owner's manual will give you the normal operating range. On gen 1 bikes all you have is an overheating light, no temperature readout.

I don't recommend removing the cap from the radiator after the engine has warmed up. It's safer to take the cap off and then start warming up the engine. You can see the coolant flowing when the thermostat opens. The absolute safest way is to remove the thermostat and see if the pump is working. This involves removing all the coolant first so it's kind of a PITA. Definitely do this if your testing says you're getting no flow. The thermostat may be bad/stuck.

 

[RandyO]

About 40,000 miles ago, I had the temp sensor go bad on my SV, fan never came on, didn't feel like it was running hot, cause it wasn't but my overheat light was on.

 

[japgen]

Re: How hot?

Are you sure it's overheating? What temperatures are you running and is the fan kicking on and staying on? The owner's manual will give you the normal operating range. On gen 1 bikes all you have is an overheating light, no temperature readout.

I don't recommend removing the cap from the radiator after the engine has warmed up. It's safer to take the cap off and then start warming up the engine. You can see the coolant flowing when the thermostat opens. The absolute safest way is to remove the thermostat and see if the pump is working. This involves removing all the coolant first so it's kind of a PITA. Definitely do this if your testing says you're getting no flow. The thermostat may be bad/stuck.
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OK, so now I've got the coolant drained and can't get the thermostat off. I took off the hose , grounding clip and the 2 bolts, but the cover is stuck. Is there some kind of gasket that could be stuck? I'm hoping it's just a bad thermo, which would be fairly easy. Reason I say this is the fan never kicks on at any temp, which is a new occurrence on this bike. Oh yeah, I stripped the aluminum threads on the cooling fan thermo switch, so it looks like I'm into a new radiator AND switch. Any help you can give on removing the thermostat would be appreciated. thanks

 

[japgen]

About 40,000 miles ago, I had the temp sensor go bad on my SV, fan never came on, didn't feel like it was running hot, cause it wasn't but my overheat light was on.

What would cause both the cooling fan and water pump to not come on? Bad thermostat? I believe this is what I've got, but now I'm having trouble removing the thermostat.......thanks for your reply.

 

[RandyO]

What would cause both the cooling fan and water pump to not come on? Bad thermostat? I believe this is what I've got, but now I'm having trouble removing the thermostat.......thanks for your reply.

again, are you sure you are overheating? your cooling fan will never come on if the water temp doesn't get high enuf to turn it on, so if your always moving and not stoppped in traffic, there is never a reason for it to come on, I believe (somebody correct me if I am wrong) the water pump ALWAYS is pumping as long as the engine is running

I have 115,000+ miles on my SV and I can count the number of times on one hand and still have 2 fingers left over, the number of times my fan has turned on

 

[japgen]

again, are you sure you are overheating? your cooling fan will never come on if the water temp doesn't get high enuf to turn it on, so if your always moving and not stoppped in traffic, there is never a reason for it to come on, I believe (somebody correct me if I am wrong) the water pump ALWAYS is pumping as long as the engine is running

I have 115,000+ miles on my SV and I can count the number of times on one hand and still have 2 fingers left over, the number of times my fan has turned on

would a stuck or bad thermostat prevent coolant circulation and result in an extremely hot to the touch water pump casing? I think this may be what's happening.....again, thanks.

 

[zoltan]

After use the whole engine will be extremely hot to the touch, parts of the frame too.

 

[TWF]

would a stuck or bad thermostat prevent coolant circulation and result in an extremely hot to the touch water pump casing? I think this may be what's happening.....again, thanks.

yes,stuck termostat will cause problems.water pump housing is hot when motor runs.
tap termostat housing with soft hammer,it will come apart.termostat gasket is keeping two halfs glued together.