Question on coolant

[ORBlackFZ1]

Hi everyone:

2007 Gen 1 - I am the only owner. I have been servicing my own motorcycles for the last couple of years. On a recent ride, about 15 miles from my house, I stopped for gas and noticed that coolant was being blown out through the overflow reservoir. I called a tow truck and shipped the Busa back home.

Now I am trying to diagnose the problem. I have a Suzuki GSX1300R service manual and have gone through the chapter on "Cooling and Lubrication System". I have also gone through this forum and found some interesting information. Solutions ranging from new radiator cap to new head gasket. I would like to be able to properly diagnose the problem before I spend time and money replacing parts that aren't broken.

My question is concerning the post by Kiwi Rider here Post #2. When I got to his step #4, I never saw any movement in the coolant in radiator. Should there have been some movement, since the water pump is always pumping? Or should the coolant only move after the thermostat has opened?

Which way does the coolant flow into the radiator? Is it in the top (right side) and out the bottom (left side)?

I was planning on following the service manual for problem identification, but the coolant not moving didn't make sense to me.

I don't have any coolant leaks, so I was going to skip the coolant system pressure test. I would like to test the radiator cap to see if it is bad with my MityVac, but I would have to order the radiator cap attachment.

After the radiator cap, I think the next step is to test the thermostat for proper operation. I can follow the Service Manual instructions and heat it up in a pan of water with a thermometer.

It looks like the water pump would be next. Any suggestions on determining if the water pump is working properly?

The Service Manual lists a "Engine Coolant Temperature Sensor". I am guessing that is for some indicator light on the instrumentation panel and wouldn't be contributing to my problem.

Any help would be appreciated.

Thanks,
Eric

 

[Kiwi Rider]

Hi everyone:

2007 Gen 1 - I am the only owner. I have been servicing my own motorcycles for the last couple of years. On a recent ride, about 15 miles from my house, I stopped for gas and noticed that coolant was being blown out through the overflow reservoir. I called a tow truck and shipped the Busa back home.

Now I am trying to diagnose the problem. I have a Suzuki GSX1300R service manual and have gone through the chapter on "Cooling and Lubrication System". I have also gone through this forum and found some interesting information. Solutions ranging from new radiator cap to new head gasket. I would like to be able to properly diagnose the problem before I spend time and money replacing parts that aren't broken.

My question is concerning the post by Kiwi Rider here Post #2. When I got to his step #4, I never saw any movement in the coolant in radiator. Should there have been some movement, since the water pump is always pumping? Or should the coolant only move after the thermostat has opened?

Which way does the coolant flow into the radiator? Is it in the top (right side) and out the bottom (left side)?

I was planning on following the service manual for problem identification, but the coolant not moving didn't make sense to me.

I don't have any coolant leaks, so I was going to skip the coolant system pressure test. I would like to test the radiator cap to see if it is bad with my MityVac, but I would have to order the radiator cap attachment.

After the radiator cap, I think the next step is to test the thermostat for proper operation. I can follow the Service Manual instructions and heat it up in a pan of water with a thermometer.

It looks like the water pump would be next. Any suggestions on determining if the water pump is working properly?

The Service Manual lists a "Engine Coolant Temperature Sensor". I am guessing that is for some indicator light on the instrumentation panel and wouldn't be contributing to my problem.

Any help would be appreciated.

Thanks,
Eric

Hi there,
If the thermostat opens, the hose at the top and the hose at the bottom will be both the same temp . . .that is IF the radiator is NOT BLOCKED and has FULL flow across the core from the left tank to the right tank.
Also, when the thermostat is open you should be able to look into the open rad cap opening and see the coolant moving and flowing, especially as you bring the revs up.
When the thermostat is closed, the coolant level in the radiator (viewed through the rad cap opening) will raise and lower with virtually no flow visible, as you bring the revs up and down . . then when the thermostat opens, the coolant will be seen flowing across the opening.
If you see little to no movement and you are sure the thermostat is open, there is either a blocked radiator core . . OR a water pump issue.
It's unlikely to be a water pump problem, they very seldom give trouble, but check the flow resistance in the radiator core . . fill the radiator at the top inlet hose fitting tube, and look at the rate of flow as it comes out the lower hose fitting tube. If it's a slow flow, get the radiator cleaned out or replace it with a new one.
Re the direction of flow, the coolant goes from the thermostat to the TOP hose and exits the lower hose back to the water pump.
The coolant always goes to the top hose because as the coolant travels downward, the heat is released and travels upward, as heat always does.
So you never want heat to follow the coolant flow, it must always leave the coolant in the opposite direction to allow the coolant to discard it's heat and reduce in temperature, therefore, coolant flows downward releasing heat upward.
Regarding the Engine Coolant Temp SENSOR, that sensor relays coolant temperature back to the ECU and that data goes into the calculation for correct air/fuel ratio FOR the particular temperature the coolant/engine is at. It basically determines mixture on a cold start up and corrects the mixture as the motor warms up.
I hope this was helpful.
Kiwi

 

[WuzzaCBXRider]

The coolant circulates when the stat is open. When closed, is the time (duration) it should take to cool it down enough to get exchanged with the warmer engine coolant supply. The cap should hold pressure during the heat/cooling cycles. The coolant temp sensor is inline on the left side of the motor I believe, it’s been awhile since I’ve had the fairings off. Kiwi is a qualified (paid) mechanic and should chime in soon. BTW, I’ve had RVRoadhelp towing service forever and the costs these days for even a short tow is too expensive not to have it. Good luck. Oops, he beat me to it.

 

[Kiwi Rider]

The coolant circulates when the stat is open. When closed, is the time (duration) it should take to cool it down enough to get exchanged with the warmer engine coolant supply. The cap should hold pressure during the heat/cooling cycles. The coolant temp sensor is inline on the left side of the motor I believe, it’s been awhile since I’ve had the fairings off. Kiwi is a qualified (paid) mechanic and should chime in soon. BTW, I’ve had RVRoadhelp towing service forever and the costs these days for even a short tow is too expensive not to have it. Good luck. Oops, he beat me to it.

You are correct Terry, the temp SENSOR is located on the back of the cylinder block, on the left side of the thermostat housing.
The switch on the radiator tank is the thermoswitch for the fan operation.

 

[ORBlackFZ1]

Hi everyone,

Thanks for the quick response.

If the thermostat opens, the hose at the top and the hose at the bottom will be both the same temp . . .that is IF the radiator is NOT BLOCKED and has FULL flow across the core from the left tank to the right tank.
Also, when the thermostat is open you should be able to look into the open rad cap opening and see the coolant moving and flowing, especially as you bring the revs up.
When the thermostat is closed, the coolant level in the radiator (viewed through the rad cap opening) will raise and lower with virtually no flow visible, as you bring the revs up and down . . then when the thermostat opens, the coolant will be seen flowing across the opening.
If you see little to no movement and you are sure the thermostat is open, there is either a blocked radiator core . . OR a water pump issue.
It's unlikely to be a water pump problem, they very seldom give trouble, but check the flow resistance in the radiator core . . fill the radiator at the top inlet hose fitting tube, and look at the rate of flow as it comes out the lower hose fitting tube. If it's a slow flow, get the radiator cleaned out or replace it with a new one.

When I started your test steps yesterday, coolant kept dripping out the radiator cap opening. About 1/2 a cup came out in total. I didn't let the temperature gauge get to the halfway mark before I got nervous and shut the engine off.

It sounds like I need to do the test steps again and wait a little longer for the thermostat to open. My temperature gauge usually runs just below the halfway mark. I assume the thermostat should be open by then....

Once the thermostat opens, I should see the coolant moving through the radiator cap opening. If the temperature gauge gets to the halfway mark, and the coolant isn't moving, then I will pull the thermostat and check it.

Re the direction of flow, the coolant goes from the thermostat to the TOP hose and exits the lower hose back to the water pump.
The coolant always goes to the top hose because as the coolant travels downward, the heat is released and travels upward, as heat always does.
So you never want heat to follow the coolant flow, it must always leave the coolant in the opposite direction to allow the coolant to discard it's heat and reduce in temperature, therefore, coolant flows downward releasing heat upward.

Thanks for the clarification on the water flow direction. That makes sense about entering hot at the top and cooler at the bottom. Sorry, but Thermodynamics was my worst subject in the engineering undergraduate program.

Regarding the Engine Coolant Temp SENSOR, that sensor relays coolant temperature back to the ECU and that data goes into the calculation for correct air/fuel ratio FOR the particular temperature the coolant/engine is at. It basically determines mixture on a cold start up and corrects the mixture as the motor warms up.

It sounds like the SENSOR is not contributing to the problem.

I hope this was helpful.
Kiwi

Absolutely helpful and greatly appreciated.
Eric

 

[Kiwi Rider]

@ORBlackFZ1
Hey. Eric,
Just about the coolant dripping from the radiator opening while the motor is running and warming up. . . This is caused by thermal expansion, totally normal.
One other thing, you could fill the radiator and squeeze the hoses to bleed as much air out as possible, then fit the cap and run the engine till it warms up... keeping an eye on the temp gauge, the expansion bottle and listening for the fan to start up. I’ll explain why I’m saying this . .
I’m a 40 year veteran in the trade as a car mechanic and I have 2 years of workshop experience on bikes. With bleeding car cooling systems the safest way ( to not trap air) is to leave the cap off until the thermostat opens, but with the smaller system on a motorcycle it appears it’s ok to put the cap on and then warm it up and monitor thermostat, temp gauge, fan operation and expansion bottle. This what I’ve observed the other bike techs doing in the workshop.
There’s far greater chance of air locks forming in a car system because it’s so much greater volume and also the heater core can easily trap air.
So give that a try and let us know how it goes for you.

 

[ORBlackFZ1]

Help a Newbie out! What is the best way to get the thermostat out without damaging it? The rubber seal is really holding it in.

Any suggestions from those of you that have removed one?

Thanks in advance,
Eric

 

[ORBlackFZ1]

I figured it out. Long-nosed bent pliers....The thermostat was still tight, but it came out with a little bit of force.

Onto the water heating test...

Thanks,
Eric

 

[ORBlackFZ1]

When I drained the coolant, I found no signs of any type of rust, corrosion or other contaminants in the coolant. The coolant looked just like I put it in 2013. I think I have only put 1500 miles on my Busa since then.

Good YouTube video for removing the thermostat: BigWheelsTurning

Thermostat passed water heating test. It started opening just below 180F and was open to 8mm by 210F. I let it cool in the water and it was closed just under 180F. The thermostat met the service manual specifications.

I bypassed the cooling fan thermo-switch with a jumper and the fan came on strong. I still need to test the thermo-switch in hot oil in the upcoming days.

I ordered a Cooling System Test Kit to go with my MityVac. It should be here next week. Then I can test the radiator cap. I already have a new radiator cap, but I wanted to check the obvious parts of the cooling system before I get caught out on the road with coolant blowing out the reservoir overflow tube, again.

After I check the radiator cap, I think it is time to put the Busa back together, fill it with coolant, burp it and see if it will pass Kiwi Rider's coolant system test steps.

Hopefully, I will be able to see the water circulating in the radiator this time.

Eric

 

[HayaWakened]

When I drained the coolant, I found no signs of any type of rust, corrosion or other contaminants in the coolant. The coolant looked just like I put it in 2013. I think I have only put 1500 miles on my Busa since then.

Good YouTube video for removing the thermostat: BigWheelsTurning

Thermostat passed water heating test. It started opening just below 180F and was open to 8mm by 210F. I let it cool in the water and it was closed just under 180F. The thermostat met the service manual specifications.

I bypassed the cooling fan thermo-switch with a jumper and the fan came on strong. I still need to test the thermo-switch in hot oil in the upcoming days.

I ordered a Cooling System Test Kit to go with my MityVac. It should be here next week. Then I can test the radiator cap. I already have a new radiator cap, but I wanted to check the obvious parts of the cooling system before I get caught out on the road with coolant blowing out the reservoir overflow tube, again.

After I check the radiator cap, I think it is time to put the Busa back together, fill it with coolant, burp it and see if it will pass Kiwi Rider's coolant system test steps.

Hopefully, I will be able to see the water circulating in the radiator this time.

Eric

#c10's Garage

 

[ORBlackFZ1]

HayaWakened:

Thanks for the video. I learned how to "Burp" my 2007 Busa with the first coolant change. I didn't have to do squats at the gym for the next week. I will make sure I "Burp" it this time too.

Eric

 

[ORBlackFZ1]

Hi everyone:

Top photo shows when the cooling fan thermo-switch turned on.
Bottom photo shows the testing equipment with motor oil as the heating medium.

I finished testing the cooling fan thermo-switch. I checked it three (3) times. It definitely does NOT meet the service manual specifications. It turned on at 240F and closed at 218F each time. Even though my thermometer may not be the most accurate, I doubt that it is off by 20F. I am going to put in a new switch just to be cautious.

Is the switch a common part that goes out of specification? Of course, I have to remember that this is a 2007 Busa and parts do decay with time.

Eric

 

[Berlin Germany]

@ORBlackFZ1

very nice post.

for some more infos
have a little look at this post

overheating - unusual cause but maybe not | General Bike Related Topics

My 2004 started overheating when idling or at stop lights. but the reservoir level was fine and the fans came on on time. I searched the forum and came up with lots of useful info, especially about how critical it is to bleed all the air out of the system and how to best do it. Also a number...

www.hayabusa.org

there i wrote some hints and recom´s
could be helpful.

 

[ORBlackFZ1]

I got my new Mityvac MV4510 Motorcycle Cooling System Test Kit today from Amazon. I had to "test" it out and see how it worked. My old radiator cap started hissing at just over 10psi. The new radiator cap held until 16psi. Looks like I have found the source of my empty reservoir. Hopefully, the new radiator cap and cooling fan switch will get me back riding the Busa.

The Mityvac instructions included three (3) tests: 1. Static Pressure Test (engine off), 2. Dynamic Pressure Test (Engine On) and 3. Cap Pressure Test. I will have to perform #1 & #2, after I get the new cooling fan switch installed.

Test #1 diagnoses cooling system leaks and #2 diagnoses: a. cooling system leaks, b. cylinder head damage, c. blown head gasket & d. cracked block. For $40, it is a pretty handy tool for a DIY'er.

I ordered the cooling fan switch today and will just have to wait for it to arrive.

Thanks for all the help,
Eric

 

[ORBlackFZ1]

@ORBlackFZ1

very nice post.

for some more infos
have a little look at this post

overheating - unusual cause but maybe not | General Bike Related Topics

My 2004 started overheating when idling or at stop lights. but the reservoir level was fine and the fans came on on time. I searched the forum and came up with lots of useful info, especially about how critical it is to bleed all the air out of the system and how to best do it. Also a number...

www.hayabusa.org

there i wrote some hints and recom´s
could be helpful.

Thanks for the link. Nice modification for the cooling fan switch!

I am amazed at the "green gunk" in your radiator. (Slime is for emergency tire repair....not fixing coolant leaks....I am a Newbie and I know that....just saying.....)

Thanks again for the help,
Eric

 

[ORBlackFZ1]

Ok....I finally received the new cooling fan thermo-switch. I got it installed, filled the radiator with distilled water and burped it a couple of times. Added more water and followed Kiwi Rider's steps. Everything checked out!!! The fan came on and started cycling properly.

I will let everything cool and drain the distilled water from the system. Refill with 3.2 quarts of 50/50 coolant/distilled water and burp it a few more times. Test ride and then burp it again. Hopefully, by replacing the thermo-switch and the new radiator cap, my coolant issues will be solved.

On to front fork oil change and then to synchronizing the fuel injectors.

The weather is so nice, I hate to leave the Busa in the shop, but thankfully after rebuilding the 2002 FZ1 last winter, I can ride.

Thanks for all the help,
Eric