Somethin Fishy with the Temps - Supsect T-Stat

[FinalImpact]

I'm going to throw this out and see if others have the same issues. If so, I suspect the Thermostat is stuck open and/or not closing far enough to control the engines temperature properly (maybe not moving at all??).

At the end of last year I noticed that while sitting at light in traffic the temps reached 212 and then some fan action for cooling. Previously the fan NEVER used to come on and the temps were not that high. Because I sat in traffic for extended periods I thought little of it. Now as I ride in cooler temps, I see at speed the temps remain below 180F for extended periods of time and then when I stop at a light they quickly rise. When I say quickly I mean a degree per second until the fan comes on even with an ambient temp of only 55F. THIS IS NOT how it used to be.

As stated, I suspect the T stat is not closing all the way and needs replaced as it should and USED to sit right around 180 all the time no matter what I did and now its cool when at speed and hot fast when parked. With water circulating too fast that keeps the temps low at speed. But rising fast like it does when there is minimal air flow seems like a trait of not opening too.

I'll order a new one and see what that does. Keep you posted...
Anyone else have behavior like this? MPG has dropped also. . .

JJD9452

 

[darius]

Yeah 212F sounds rather high for these temps. But my experience has been the FZ6 does not like sitting.

Coolant temp shoots up after getting off the highway at a red light (a deg. every few seconds) then tumbles once moving again.

Fan on kicks on @ 200 on mine and that'll usually keep it at 205 max. I changed my coolant last year it made quite difference. The fan coming on for me is routine at stops outside of winter.

 

[pookamatic]

This is a timely post, as I'm having suspicious cooling behavior. FinalImpact, see the "Check Engine Light Help" thread you commented on last week.

Anyway, I have a tstat on order so I took the original out last night a boiled it. I took it out and cooled it several times and it did operate as i would expect. However, my wishful thinking says it's not opening up enough while hot.

200
View attachment 47723

190
View attachment 47724

180
View attachment 47725

170
View attachment 47726

160
View attachment 47727

 

[Gelvatron]

Keep me updated final as my bike on cool days never reaches 210 but on a 80+ day it's 212
As soon as I come to a stop and the fans Kick on although that is two different times a day

 

[FinalImpact]

Pook, ah yes, the "traits" seem very similar (http://www.600riders.com/forum/fz6-technical/48692-check-engine-light-help.html ). I wish I had IR temp gauge capable of CAT temperatures (550 ~ 600C). << Is there some chance our 08 CAT's are misbehaving causing these temperature issues? I really think not but I'm just throwing it out there. Mine bike is now very speed sensitive as far as temps are concerned but the most telling sign is the longer span it takes to warm up to temp.

So what temp does your stat officially open at?

 

[pookamatic]

It's starts moving at the exact temp I would expect... 160F/71C. (Says 71C on the stat)

I'll repeat the process on the new one and report back. Hopefully get it in a day or so.

 

[fb40dash5]

I can't speak to the cooling system on the FZ specifically, but...

My truck's cooling system can be a PITA to get all the air out of. Last time I did a t-stat in it, I had the bright idea to take the little poppet out of the bleed hole, and make the bleed hole about 1/8" diameter. The change was insane. Even in pretty warm weather, it would never come off the C mark on the gauge, even sitting, and the heat would never blow anything close to even warm. It was crazy what a difference that little bit of flow made.

Maybe the Fizzer's smaller cooling system negates that... a lot? But my guess is that your t-stat isn't stuck open, or the inability to close off your radiator would mean it would basically never warm up (barring some other fault that would cause it to overheat) and the temp would fall through the floor when you're moving. But, never hurts to check, and if you're gonna check, might as well replace it and flush your cooling system, it's worth a shot. I wonder if my coolant Super Funnel has an adapter that would work with the FZ's cap and its location, that thing is awesome for filling cooling systems...

 

[FinalImpact]

I can't speak to the cooling system on the FZ specifically, but...

My truck's cooling system can be a PITA to get all the air out of. Last time I did a t-stat in it, I had the bright idea to take the little poppet out of the bleed hole, and make the bleed hole about 1/8" diameter. The change was insane. Even in pretty warm weather, it would never come off the C mark on the gauge, even sitting, and the heat would never blow anything close to even warm. It was crazy what a difference that little bit of flow made.

Maybe the Fizzer's smaller cooling system negates that... a lot? But my guess is that your t-stat isn't stuck open, or the inability to close off your radiator would mean it would basically never warm up (barring some other fault that would cause it to overheat) and the temp would fall through the floor when you're moving. But, never hurts to check, and if you're gonna check, might as well replace it and flush your cooling system, it's worth a shot. I wonder if my coolant Super Funnel has an adapter that would work with the FZ's cap and its location, that thing is awesome for filling cooling systems...

My life experience says its the stat and as you point out here, too little or too much flow makes all the difference.

For reference, on 55F day, idling from cold start would have the temp at 115F in 5 min and/or the time it takes get my helmet & gloves on and idle out of parking lot. Currently doing this same act and its too low to register.

 

[FinalImpact]

FWIW:
PN: 5SL-12410-00-00, THERMOSTAT ASSY, Aprox~ $15.40

Pook, did you see a seal or gasket? Parts Fish doesn't show how the housing is sealed to the block. Thanks!

Also - Yamaha used this Stat in a few places...

YEAR, MAKE, MODEL
2003, Yamaha, YZF-R6
2003, Yamaha, YZFR6SRC YZFR6
2003, Yamaha, YZFR6SR YZFR6
2003, Yamaha, YZFR6RC YZFR6
2003, Yamaha, YZFR6R YZFR6
2004, Yamaha, YZF-R6
2004, Yamaha, YZFR6SS YZFR6
2004, Yamaha, YZFR6SCS YZFR6
2004, Yamaha, YZFR6SC YZFR6
2004, Yamaha, YZFR6S YZFR6
2004, Yamaha, FZ600SSC FZ6
2004, Yamaha, FZ600SS FZ6
2004, Yamaha, FZ600
2005, Yamaha, FZ6TC
2005, Yamaha, FZ6T
2005, Yamaha, YZFR6TC YZFR6
2005, Yamaha, YZFR6T YZFR6
2005, Yamaha, FZ6STC FZ6
2005, Yamaha, FZ6ST FZ6
2006, Yamaha, YZFR6VC R6
2006, Yamaha, YZFR6SVC R6S
2006, Yamaha, YZFR6SV R6S
2006, Yamaha, YZFR6V R6
2006, Yamaha, YZFR6SPVC R6 50TH ANNIVERSARY EDITION
2006, Yamaha, YZFR6SPV R6 50TH ANNIVERSARY EDITION
2006, Yamaha, FZS6VC YZ6
2006, Yamaha, FZS6V FZ6
2007, Yamaha, YZFR6SWC R6S
2007, Yamaha, YZFR6SW R6S
2007, Yamaha, YZFR6RWC
2008, Yamaha, YZF
2008, Yamaha, FZ6
2008, Yamaha, YZF
2009, Yamaha, FZ6RYB/FZ6RYCL/FZ6RYL/FZ6RYCB
2009, Yamaha, FZ6RYY/FZ6RYCY/FZ6RYCW/FZ6RYW
2009, Yamaha, FZS6YL/FZS6YB/FZS6YCL/FZS6YCB
2009, Yamaha, YZFR6SYCL/YZFR6SYCB/YZFR6SYL/YZFR6SYB
2009, Yamaha, YZFR6YCL/YZFR6YL/YZFR6YCB/YZFR6YCW/YZFR6YB/YZFR6YW
2009, Yamaha, YZFR6YCO/YZFR6YO
2011, Yamaha, FZ6R FZ6RAB/FZ6RACB
2011, Yamaha, FZ6R FZ6RAO/FZ6RACO
2011, Yamaha, YZFR6 YZFR6AB/YZFR6ACL/YZFR6AL/YZFR6ACB
2011, Yamaha, YZFR6 YZFR6ACR/YZFR6AR
2012, Yamaha, FZ6R FZ6RBB/FZ6RBCB
2012, Yamaha, FZ6R FZ6RBW/FZ6RBCW
2012, Yamaha, YZF-R6 YZFR6BCB/YZFR6BL/YZFR6BCL/YZFR6BB
2012, Yamaha, YZF-R6 YZFR6BCW/YZFR6BW

 

[pookamatic]

Pook, did you see a seal or gasket? Parts Fish doesn't show how the housing is sealed to the block. Thanks!

Yes - the gasket goes around the stat and locks on by way of elasticity. I did not see or order one so I'm assuming a new stat includes a gasket. The original looks fine, however.

 

[TownsendsFJR1300]

Yes - the gasket goes around the stat and locks on by way of elasticity. I did not see or order one so I'm assuming a new stat includes a gasket. The original looks fine, however.

Were you able to pull the thermostat housing WITHOUT PULLING the TB's?
(I know its tight, likely doable)..

Don't know if it'd make much of a difference but in checking the thermostat, its preferred to have it suspended in the water and NOT resting on the bottom.

I don't think the new one is going to open any more than what you have, but please test it before installing to see if the opening is any more.

BTW, about 3 weeks ago, on my neighbors 200HP Yamaha, 2 stroke outboard, we had to replace the two (one in each head, V6)thermostats. One thermostat was fine, the other was crooked and locked up on the shaft from salt water and age... Didn't fix the overheating issue, last wek we replaced the rubber impellor which was very, worn (took a permanent offset after 5 years or so). Still overheating some, but at a higher RPM. I believe we'll be pulling at least the coolant /head cover(s) off and removing salt that's apparently built up over time (he's not real big into flushing with fresh water after salt water use)

 

[pookamatic]

Were you able to pull the thermostat housing WITHOUT PULLING the TB's?
(I know its tight, likely doable)..

Yes - the near bolt was pretty simple to get at. The far (inner) bolt was tough. Not looking forward to having to put it back together. I used a 3/8 ratchet to a 6 point 10mm. For one of the bolts, forget which, it was easier with a snub (~1") extension.

I don't think the new one is going to open any more than what you have, but please test it before installing to see if the opening is any more.

That's my concern... THEN what??

I should have been more clear when I said that I "flushed the radiator." More accurately, I "removed all old coolant by filling it up with dist water and running the bike until hot, twice." Before I put it all back together, should I buy some flush solution?

 

[TownsendsFJR1300]

I just checked my 07 Yamaha manual. Spec's call for 8mm's FULLY OPEN at 185 degrees(F), it starts to open at 160 degrees (F)

As for flushing, unless you see some serious corrosion inside (maybe pull another hose, maybe the ones to the oil cooler as well) and examine for excessive corrosion. I would think just putting the garden hose in line and flushing would get most contaminants out. If you wanted to throw in some distilled water as a final flush, that's fine.

Something that hasn't been addressed... The radiator cap. As I understand, if its not holding the specified pressure, it'll tend to overheat. See below:
The Signs of a Bad Radiator Cap | eHow.com

 

[pookamatic]

Then I'd say my stat is operating per spec. Will repeat test on the new one but as of right now, I'm sorta ruling it out. I say sorta because my problem is almost exactly like Final's. The stat simply doesn't appear to be doing it's job *correctly*.

My 'flushes' were simply fill ups with dist water, then idling until temp reached 180.

Good call on the cap. Come to think of it, since changing the coolant out last week, the reservoir did look lower than I originally topped it off at (F while cold). Either I didn't check its level after that first full operating temp, and some trapped air forced some pull on the reservoir, -or- there was some boil over when the temps in 212. With proper pressure, this shouldn't be.

AutoZone has a loaner tester available. Will report back.

 

[FinalImpact]

A bum pressure cap usually does one of these:
A: dumps fluid into reservoir before reaching set pressure. Often you will see the reservoir over fill and/or boil over from its own vent. If the ENGINE is not actually over-heating, the cap is bad.
B: Dumps fluid on the ground from the outer seal to the rim of the radiator.
C: Won't pull a vacuum and allow the system to suction fluid in from the reservoir. Thus, any time you check check the actual level of the system with the cap off, the radiator and block will be low on fluid.

The system can not have a leak at the cap or anywhere else or it will not pull fluid in from the reservoir when the engine cools. As the coolant reduces in volume during cool down, the system pulls coolant in from the res when working properly. It is normal for the coolant to expand as the engine comes up to temperature and it may push out a small amount of fluid into the res as it warms. As it cools, the cap allow fluid to be pulled from the Res into the cooling system to refill the block.

Mine does not misbehave in any of these fashions.

 

[FinalImpact]

Then I'd say my stat is operating per spec. Will repeat test on the new one but as of right now, I'm sorta ruling it out. I say sorta because my problem is almost exactly like Final's. The stat simply doesn't appear to be doing it's job *correctly*.

.. .. ..

The critical info here is does the stat meet spec or not?

What NICE GUYS!!! They gave us the spec!! <<I love these guys!!!!
The chart in the manual shows the stat opening rate per temp.

160.0F = 0 mm CLOSED
172.5F = 4 mm
185.0F = 8 mm FULLY OPENED

^^ From a Need to know, that is Great info to have!!! Now we just need someone to stick there hands in near boiling water and measure it for us! lol

 

[mxgolf]

My 07 has always seemed to get hot when I get into any traffic. I replaced the antifreeze last year and it's a bit better but not much. Fan comes on at about 210. The thermostat is the stock one. I really did not think about it not working properly. I just have ridden it that way. I know she does not like the heat much. Runs much better in cooler temps as I am sure all bike do.
Thanks for all the information.

 

[pookamatic]

Final: I didn't take out a ruler to measure the gaps in the stat, but it appears to meet spec.

So I'm not 100% sure, but I believe my cap is bad. During the pressure test, I didn't quite see 16 pounds. Closer to 15 actually. And it didn't hold the pressure there very well at all. I'm not sure how good their tool is though. The pressure dropped to 10 psi within a few seconds. I'm already regretting not testing one of their's off the shelf but if the tool is fully functional, my guess is the cap needs to be replaced.

I have no idea if this fading cap is causing my issue though.

 

[FinalImpact]

If its pushing fluid into the tank as it hits 185 or so I'd say yes. If your tank is over flowing, I'd say yes. If neither are true, likely test/equipment error. Read the section up a few clicks. It covers most of it.

 

[TownsendsFJR1300]

Final: I didn't take out a ruler to measure the gaps in the stat, but it appears to meet spec.

So I'm not 100% sure, but I believe my cap is bad. During the pressure test, I didn't quite see 16 pounds. Closer to 15 actually. And it didn't hold the pressure there very well at all. I'm not sure how good their tool is though. The pressure dropped to 10 psi within a few seconds. I'm already regretting not testing one of their's off the shelf but if the tool is fully functional, my guess is the cap needs to be replaced.

I have no idea if this fading cap is causing my issue though.

Per the manual, (page 6-3, 07-09 manual) spec's for the radiator cap call for 13.2 PSI to 17.5 PSI and NO DROP IN PRESSURE for 10 seconds.

Also, from the manual (page 9-3)troubleshooting:

Cooling system
1. Coolant
• Low coolant level
2. Radiator
• Damaged or leaking radiator
• Faulty radiator cap
• Bent or damaged radiator fin
3. Water pump
• Damaged or faulty water pump
• Thermostat
• Thermostat stays closed
• Oil cooler
• Clogged or damaged oil cooler
• Hose(s) and pipe(s)
• Damaged hose
• Improperly connected hose
• Damaged pipe
• Improperly connected pipe