Do I have a head gasket leak or need a thermostat?

Tom24GR

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Hello everyone,

I took my 2007 FZ6 for a ride for the first time in about 10 days and I noticed the temp gauge running hot. Usually the fan kicks on at about, I would say, 170-180 ish (unless I'm clearly mistaken). But yesterday my fan would only kick on around 210. it would bring it back down to 190 and then stop. This is a brand new fan and when running it in diagnostics mode, it powers on and works just fine. In other words, its not the fan or the relay or fuse that is the problem here. This would lead me to think its some sort of coolant temp sensor or a thermostat that doesn't work.

BUT ALSO

I noticed that my reserve coolant reservoir was empty. I then drained the oil and it came out foamy(the bubbles were a slightly lighter hue of red than the oil itself) [don't worry, motul engine oils are for some reason red]. But there was no milkshake appearance, just bubbles. Now I have seen online that draining the oil after a ride can produce bubbles but then again, this is the first time I drained it while super hot so I am haven't done it before to be sure or not. When I remove my dipstick while the bike is running, there are NEVER any bubbles on the dipstick itself.

Do you guys believe that this could be a head gasket leak? The bike has 23k miles. I have one of those gasket leak testers that people use on cars but I wanted to come here get an opinion. Those things can be very fickle when it comes to results.

Have any of you replaced a gasket on this bike before? I would figure that its much easier than my car (boxer engine head gaskets are a nightmare) but I wanted to hear form you guys.

Anyway, thanks in advance.
 
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TownsendsFJR1300

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176F or so on '07 is normal, not stuck in traffic (in SW Florida so your sounds normal.)

The fan as I re-call, kinks on at around 210F and bring back down likely to somewhere where yours is, again, yours sounds normal.

Sounds like your running 7100 full synthetic correct?...

I never changed my oil with it that hot but wouldn't think they'd be bubbles un-less over filled by a good amount. Water intrusion would make the oil, as you posted brownish, milk-shakey in color .

I know on my overflow tank, it's somewhat hard to see the actual level (plastic tank turns yellow, etc). I sometimes just dip a screwdriver into the tank (keeping my finger at one spot to find the actual level).

I gather there's NO OILY film inside the radiator?.

Depending on when the coolant was last replaced, you could have a slightly loose hose clamp(and some minor corrosion with the aluminum). I would at least take a screwdriver to every hose clamp and check it. There could be some slightly loose /leaking and it evaporates from the hot block W/O you noticing it. .

If you have the time and knowledge, I'd pull each hose from the block, clean out any and all white, corroded aluminum goo. Some rough sand paper to get the aluminum and inside hoses clean again would help stop any leakages at those points (nice and clean).

Should you wish to test further, (don't think you need to but), get a radiator pressure tester tool, (that goes onto the radiator allowing you to pump it up) and make sure the system is holding pressure..

If it is leaking, a peek at the spark plugs may tell you something is a-miss.

To go further (if need be), a "leak down test" on each cylinder (at TDC, compression stroke, crankshaft locked from moving) would show leakage/ a blown head gasket and the general health of you engine. besides the tool, you need an air compressor. Pressure would drop, visibly more that the others.

As a side note, it EXTREMLY RARE for these engines to blow a head gasket. Don't think I've ever read on any on this forum in 12 years.. I seriously doubt you have any major issues but corrosion at hose connections (especially if no coolant changes) have been done. Many heat cycles over 14 years will /can cause some seepage...


.


.
 
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Tom24GR

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I am 100% sure that it is not overfilling. 2.8L of 7100 with a new filter. Actually, when checking the disptick, while on centerstand, I had a little less than that (due to a slight oil pan leak). There is not a milkshakey appearance just bubbles which are lighter in color than the oil itself.


I did a full coolant flush like two months ago. The inside of the radiator is rusty, and I do see a sort of film in the coolant but I just thought that to be disintegrated rust. Is that film a sign?

Additionally, when I changed my spark plugs back when I first got the bike, they were oily- so , maybe that is a sign of the gasket too?
 

trepetti

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176F or so on '07 is normal, not stuck in traffic (in SW Florida so your sounds normal.)

The fan as I re-call, kinks on at around 210F and bring back down likely to somewhere where yours is, again, yours sounds normal.

Sounds like your running 7100 full synthetic correct?...

I never changed my oil with it that hot but wouldn't think they'd be bubbles un-less over filled by a good amount. Water intrusion would make the oil, as you posted brownish, milk-shakey in color .

I know on my overflow tank, it's somewhat hard to see the actual level (plastic tank turns yellow, etc). I sometimes just dip a screwdriver into the tank (keeping my finger at one spot to find the actual level).

I gather there's NO OILY film inside the radiator?.

Depending on when the coolant was last replaced, you could have a slightly loose hose clamp(and some minor corrosion with the aluminum). I would at least take a screwdriver to every hose clamp and check it. There could be some slightly loose /leaking and it evaporates from the hot block W/O you noticing it. .

If you have the time and knowledge, I'd pull each hose from the block, clean out any and all white, corroded aluminum goo. Some rough sand paper to get the aluminum and inside hoses clean again would help stop any leakages at those points (nice and clean).

Should you wish to test further, (don't think you need to but), get a radiator pressure tester tool, (that goes onto the radiator allowing you to pump it up) and make sure the system is holding pressure..

If it is leaking, a peek at the spark plugs may tell you something is a-miss.

To go further (if need be), a "leak down test" on each cylinder (at TDC, compression stroke, crankshaft locked from moving) would show leakage/ a blown head gasket and the general health of you engine. besides the tool, you need an air compressor. Pressure would drop, visibly more that the others.

As a side note, it EXTREMLY RARE for these engines to blow a head gasket. Don't think I've ever read on any on this forum in 12 years.. I seriously doubt you have any major issues but corrosion at hose connections (especially if no coolant changes) have been done. Many heat cycles over 14 years will /can cause some seepage...


.


.


+1 on Scott's recommendations. The radiator pressure tester is the easiest to use and should quickly determine if you have a coolant system leak. You did not mention when the last time you checked the coolant level in the overflow tank. Are you sure it had coolant in it when you started?

Can't speak to the bubbly oil, but I agree that if it is not milky you likely don't have coolant in it. Do a controlled test. Refill the oil and flush / fill the cooling system. Then take a ride and determine if you have a leak and if so, how much coolant is disappearing.

23k miles is nothing. My 05 has over 67,000 miles on it, runs strong and leaks nothing.
 

Tom24GR

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The entire cooling system was full and the reserve reservoir as well. 2 months ago I had drained and filled the system. I would think that in 2 months time the reservoir shouldn't empty out.

The problem is I have no air compressor but I guess it must be time to get one.

Any idea on the filmy coolant or the rust in the radiator? Any recommendations on aftermarket radiators?
 

TownsendsFJR1300

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There's really not much steel to "rust" inside the engine however rust inside indicates
lack of maintenance (no anti-freeze or someone adding straight water over years with a leak).

All aluminum block, brass radiator, not sure what the "oil cooler" is made of.

I would NOT buy a radiator as nothing yet indicates it's leaking UN-LESS YOU SEE Green residue
from it leaking. That residue is a sign of a leaking radiator. I'd verify before throwing parts at it..

I'd do the radiator pressure test first and CHECK ALL HOSES for tightness.

Gotta test the basic, more likely stuff first un-less you have excess cash and want to waste your time replacing parts that ain't broke.


.
 

Motogiro

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If you changed the coolant, there is the possibility there was air trapped somewhere and it expelled. As the engine cooled it sucked coolant from the reservoir tank and it eventually emptied. This allowed the coolant system to suck air in. The cooling system then becomes less efficient. Let the bike cool completely, open the radiator cap and top off the radiator. Replace the cap after inspecting and being sure it has a good deal. Then fill your reservoir.
 

trepetti

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If you changed the coolant, there is the possibility there was air trapped somewhere and it expelled. As the engine cooled it sucked coolant from the reservoir tank and it eventually emptied. This allowed the coolant system to suck air in. The cooling system then becomes less efficient. Let the bike cool completely, open the radiator cap and top off the radiator. Replace the cap after inspecting and being sure it has a good deal. Then fill your reservoir.


Cliff has a point, this is why I recommend a controlled test. When troubleshooting, always try the probable before the possible, and WAY BEFORE the unusual. Since the coolant was recently flushed and there is no reason to believe that the coolant loss was sudden and large, I think the trapped air theory pops to the top of the suspect list.

Refill the cooling system carefully, run the engine to force the air up to the radiator, top up the radiator and overflow, then observe..........
 

Tom24GR

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Guys, sorry about having bothered you all for nothing. I was working with my friend that day and I asked him to take a flashlight and check out the overflow reservoir and he told me "I don't see anything". I took his word that there was nothing in the reservoir, especially because the bike was running hotter than it usually does (without having pushed it any harder) (usually runs 170-180 and it was steady around 205 that day).

BUT, in fact the reservoir is full. I guess it was opaque and he didn't open up the lid. I went and checked it myself after you guys suggested pressure testing (which I did and had no leaks).

The overheating I believe can be attributed to the fact that the radiator is SUPER rusted. I put in some thermocure (rust remover) and the bike is running good now no overheating, staying steady around 170-180 like before. The stuff that came out of the radiator was DISGUSTING, but its looking real good now. Like magic.

So sorry for the false alarm. I took his word without checking before writing the post.
 

trepetti

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Guys, sorry about having bothered you all for nothing. I was working with my friend that day and I asked him to take a flashlight and check out the overflow reservoir and he told me "I don't see anything". I took his word that there was nothing in the reservoir, especially because the bike was running hotter than it usually does (without having pushed it any harder) (usually runs 170-180 and it was steady around 205 that day).

BUT, in fact the reservoir is full. I guess it was opaque and he didn't open up the lid. I went and checked it myself after you guys suggested pressure testing (which I did and had no leaks).

The overheating I believe can be attributed to the fact that the radiator is SUPER rusted. I put in some thermocure (rust remover) and the bike is running good now no overheating, staying steady around 170-180 like before. The stuff that came out of the radiator was DISGUSTING, but its looking real good now. Like magic.

So sorry for the false alarm. I took his word without checking before writing the post.

Good to hear. Always better to measure twice before you cut once. Glad it is working.
 
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