2007 Running too hot?

[rbentnail]

Yes, there are two ridges you mention. The lower one is for low level and the higher one is for high level. When I replace my coolant during my winter maintenance I usually fill it up to about 2" above the top ridge the first time to "burp" the radiator then check it once in a while. After about 2 weeks I don't have to add any more.

Also- the overflow/vent hose (not shown in your picture) should run down, ending below and to the aft of your oil filter. Bend way down and you'll see a bolt/screw that holds the last aft bit of fairing in place, below and aft of the oil filter. Take that bolt/screw out and gently flex the plastic out and make sure your hose isn't folded/kinked/otherwise obstructed. Sometimes it gets kinked behind the little piece of foam (you'll see it), especially if something unusual happens. Please DAMHIK. This could make the top of the overflow reservoir pop off.

One more thing, and not to sound dickheaded-ish, but did you receive and read the owner's manual? Many of our questions (like "Ok, I assume this is the coolant reservoir?") are very basic and are answered in the manual, sometimes with pictures and everything. If you don't have one you can read/download it here.

 

[renink]

One more thing, and not to sound dickheaded-ish, but did you receive and read the owner's manual? Many of our questions (like "Ok, I assume this is the coolant reservoir?") are very basic and are answered in the manual, sometimes with pictures and everything. If you don't have one you can read/download it here.

Thanks for the link. Unfortunately I do not have the manual. The dealer didn't have it and couldn't find the bag liners either. I made him replace the bag liners which he shipped to me at a later time and I gave him time to look for the book and pretty much never bothered going back to that dealer since it is so far away from where I live.

I actually searched online for posts about adding fluid and looked through YouTube before posting here. I read about the bottle and just needed confirmation that it was the right one. I added some fluid for now and will look at that tube this weekend when I can spare some time to work on teh bike.

Thanks.

 

[mcatrophy]

My experience is that having filled the bottle to the upper mark when cold, after a few runs it drops to about one third up from the lower mark, it then sits there until the next service.

This has been the case on both my FJRs.

I now tend not to bother checking any more (same with the oil level) unless about to go on a long trip.

Since adopting this "strategy", I've never added any. Coolant or oil.

 

[Constant Mesh]

From the parts diagrams I've seen the Gen III's don't have the high idle wax motor gizmo found on the earlier FJRs. There was a continuous flow of coolant to this unit which bypassed the thermostat flow valve. Maybe this flow helped smooth out the rise in coolant temperature as the engine warmed from a cold start.

On the Gen III all engine coolant has to pass through the thermostat valve except for a small quantity which goes through the breather hole in the thermostat. Of course the thermostat has no effect on the coolant flow in the oil/coolant heat exchanger on the front of the engine.

 

[RossKean]

Zombie resurrection!!!

I am noticing that my high-mileage '07 is running significantly hotter in the last year or so. Not especially alarming because it never hits the nuclear meltdown stage (cue "China Syndrome" clip here). Highway on a hot day (95 °F), it will run 5 bars, sometimes 6 (out of 10). Almost never runs below 4 bars at any ambient temperature. Stop and go traffic on a 70 °F day it will run warm enough for the fans to come on. Never used to do that as long as I was moving at least a bit. Probably just over one bar higher than normal all the time and seems to get up to "fans-on" a lot faster.

Coolant is properly topped off. I wouldn't expect internal deposits in cooling passages because I always use a decent brand name coolant mixed with distilled water.

Since the anomalous behavior occurs when there is little or no air flow over the radiator, I'm guessing that radiator plugging (internally or externally) is less likely to be the primary issue.

I'm thinking that the thermostat is the most likely culprit although it is clearly working at least to some extent.

How many have replaced their thermostat on a Gen II?

Did it make any difference to normal operating temperatures? i.e. did it fix the issue?

Should I bother? - It is working OK for now so is it likely to fail to the extent where it leaves me stranded?

Anything else I should consider?

Thanks

 

[rbentnail]

Since it doesn't seem to be urgent yet, I'd start with the simple stuff:

- clean the radiator fins with an A/C foaming cleaner. That stuff gets way down in there;

- check for kinked hoses :A) from the radiator to the overflow reservoir, and B) from the overflow to the ground (down along by the oil filter);

- does coolant level in overflow rise when heating and lower when cooling off, i.e., is the radiator cap working properly?

 

[RossKean]

I am pretty sure the radiator cap is working correctly (doesn't leak and reservoir volume does seem to change) and I am sure there are no kinked hoses. I did soak the radiator with a reasonably mild generic cleaner and sprayed it with a medium pressure hose (so as not to damage fins). I may try a specialized cleaner but, as I mentioned, I don't think it is the radiator since I notice it heating up faster than normal when the bike isn't moving - radiator has little cooling capacity in still air.

New thermostat isn't especially expensive but replacement is a bit of a nuisance. Not going to do it unless it has been a working solution for others.

Again, not serious at this point but don't want to find myself stranded like a Harley at the side of the road on a hot day.

 

[BkerChuck]

FWIW my '07 is in about the same boat. I see 5 bars far more often than I ever did in the past. I replaced my thermostat about 2 years ago so I'm doubting that and just did a coolant flush less than a year ago. One thing I have noticed courtesy of a coworker who rides an '06 is that I'm starting to develop a small crack in my overflow bottle. His cracked to the point where it had begun leaking and he ordered a replacement. He was showing me in our parking lot where his cracked and you can see the beginning of a crack and feel it with your fingernail on mine. I ordered a new overflow bottle Monday after work. I'm thinking possibly the system isn't maintaining full pressure as some may be bleeding off even though I don't yet show any coolant leak.

Mine isn't getting as hot as you describe but where I normally showed 4 bars it seems 5 is my new normal. As soon as replacement overflow arrives I'll swap it out and see what happens.

When I replaced my thermostat I was having more trouble with it not getting up to temp. It was during the colder months but I could ride to work, about 10 miles, and never even get to 2 bars. Changing it was pretty easy and I flushed the system while I was at it.

 

[Bill Lumberg]

I know it's not your problem, but mine behaved much the same when the shop secretly screwed with the coolant and introduced air into the system.

 

[RossKean]

...I'm thinking possibly the system isn't maintaining full pressure as some may be bleeding off even though I don't yet show any coolant leak.
...When I replaced my thermostat I was having more trouble with it not getting up to temp. It was during the colder months but I could ride to work, about 10 miles, and never even get to 2 bars. Changing it was pretty easy and I flushed the system while I was at it.

The overflow reservoir is not pressurized at all. As long as there is liquid in it and the hose from the filler neck is intact (and not kinked) and runs below the surface of the liquid, it will function properly. When pressure builds in the radiator due to expansion of the coolant due to heating, the radiator cap opens and allows coolant to overflow into the reservoir. When the coolant in the radiator cools and contracts, fluid is sucked back into the radiator. Of course, if the overflow tank is cracked it should be replaced.

 

[dcarver]

My 06 ran hot too. Pulled the rad and found hundreds of small road debris in the fins. Used water hose to flush both ways. Better but not great results. Used hydrogen peroxide to melt bug bits. Flushed again.

Noticed very very small crack so replaced radiator. Problem fixed.

 

[RossKean]

dcarver

I will, as a matter of course, clean the radiator more thoroughly than I have in the past. I won't replace it since there is no leak (at least not yet).

 

[dcarver]

dcarver
I will, as a matter of course, clean the radiator more thoroughly than I have in the past. I won't replace it since there is no leak (at least not yet).

and if you do buy, don't get cheap Chinese replacement.

 

[RossKean]

I remember reading about your eBay Chinese knockoff radiator at the time. I will go OEM if I ever have to replace it.

 

[Harald]

That must be the bane of high mileage 07's. The temps do seem to be getting higher with age.

It's been normal to hit 7 bars and fans kicking on while the bike is idling while I check the mailbox on the way home and minutes later while stopping to open the garage door (and not just on really hot days). Didn't do this in it's younger years. I've been thinking that perhaps the thermostat is staying closed too long also. A couple weeks ago I saw 8 bars for the first time with fans running after my usual mailbox/garage door stops at home. I checked the radiator and found it a little low. I topped off the radiator and accidentally filled the overflow to the top because it's almost impossible to see the level in that old tank. Short on time, I didn't bother sucking excess fluid out of the overflow. The bike rolled over to 125,000 miles last week and also experienced another 8 bars indication while stopped in hot weather (probably mid 80's ). And the excess fluid puked out of the overflow that same day after stopping(as expected).

I had a couple instances of the overflow tank overflowing and puking coolant on the ground within the last couple years. A radiator cap is cheap, so I replaced it thinking it may be weak. I also had a slow leak at the top left side of the radiator and replaced it with a used one off a salvage bike. At this point I'm going to try cleaning the radiator fins because I know they're grungy and the thermostat may be next if problems continue.

 

[RossKean]

Radiator cap (not letting pressure develop)

Thermostat (opening too early/late, insufficient flow due to incomplete opening)

Radiator exterior (metal-to-air heat transfer impaired by dirt)

Radiator interior (liquid-to-metal heat transfer or internal flow volume impaired by deposits/crud)

Marginal water pump (low flow)

Fans non-functional or insufficient speed (not the cause of initial heating rate since they only come on at 8 bars or so)

Temperature sensor faulty (system just "thinks" temperature is high)

Take your pick. If you come up with the answer, post it!! I would love to benefit from someone else's experience (and time).

I hate chasing after chronic stuff that might or might not ever get bad enough to cause a problem. You can spend a bunch of money and time on something and still never determine the root cause. On the other hand, it would be really nice if it worked the same as it did 10 years ago!

 

[Fred W]

Yeah, the cooling is not a particularly complicated system, but it sure seems to give people fits understanding it. It's pretty simple physics, really.

If when you are riding along on a cool day the temperature appears to regulate "normally", then the thermostat is doing its job correctly. Forget that

That means that any overheating at other times is as a result of radiator inefficiency. The radiator efficiency can suffer due to lack of flow on either side of the heat exchanger. Either you aren't getting enough air flow through the air side, or inadequate coolant flow through the liquid side.

If the problem happens primarily when the bike is moving slowly, following traffic that creates air turbulence, or when stopped, then the fan is suspect. If the fan is turning on and running at full speed, it could be the radiator fins are partially occluded with road spooge just in the area of the fans.

Or the radiator may be clogged up on the inside due to corrosive buildup restricting liquid flow, if you've been running crappy high silicate coolant, or not changing the coolant regularly.

Based on the vulnerable location of the radiator on these bikes, i would suspect that most of the long term degradation being observed is due to the air side of the heat exchanger getting partially blocked by road crud. The air passages are not all that big when new, and adding years of dust, sand, and corrosion from things like road salt, etc, is bound to reduce the heat exchanger's efficiency.

Try back flushing the air side of the radiator first and see how much dirt and spooge you flush out. Use only gentle cleansers and low pressure water or you risk bending the fins and making matters even worse!

 

[RossKean]

It could still be a combination of issues. I would (will) tackle them in order of decreasing likelihood and increasing cost/effort. Cleaning the outside of the radiator as well as possible is a no brainer. Changing the coolant is VERY unlikely to make any difference but I will do it in conjunction with my overdue valve check anyway. I guess a thermostat is moderately cheap and only a mild PITA to change, same with the rad cap but I probably won't bother unless someone with similar symptoms finds one of these to be a miraculous cure. I would only replace the radiator if it was leaking or the bike became unrideable due to inability to control engine temperature. I suppose I would worry about it more if I lived in Arizona rather than in New Brunswick.

 

[FJRLoonie]

I noticed an increase in indicated temperature at around 65,000 km on my '09. Nothing really significant; maybe an additional bar on the display. I couldn't really see any build up on the exterior radiator surface and figured I was due to change the coolant anyway so I replaced the thermostat as well. All back to normal since then.

 

[RossKean]

Thanks FJRLoonie. I will keep that in mind. If I am still seeing elevated operating temperatures after rad clean and coolant change (after valve check), I will consider the thermostat. Seems to be the most likely mechanical culprit after a plugged radiator. 271,000 km- I can't complain about a couple minor issues.

It has gotten to this point very gradually and if I thought it would never get any worse, I would not do anything. If it is a t-stat on the way out, I would rather change it before it failed.