Cooling System Running Hot (FIXED!!!)

I am riding in 98+ temps with very high humidity pulling a trailer on the highway. Historically, my temp gauge never runs higher than a touch above half no matter the outside temp.

Last year, I changed out my OEM bakelite waterpump for a new OEM metal impeller waterpump. I also changed the antifreeze and had cleaned a painted my radiator. The painting was more of an overspray on the fins, not much paint but the top and bottom got a good coat of paint.



The antifreeze was the orange stuff (noticed it was for GM vehicles) but also stated it was for aluminum engines. I already had it left over new from another vehicle. The antifreeze seemed thicker to me than the Preston 50/50 I have always used. The bottle said it was also 50/50, not concentrate, so I should not have needed to add water.

The thing is, from the first few times I ran the bike afterwards, it seemed to run warmer than before.

Now, on this trip to Florida, at 75 MPH, it is running so hot, it comes near to overheating, but stays just under that point. When I took the trip to Joe's in Indiana in 2010 and again with Brian in 2013, we encountered some high temps in the summer, but the engine always stayed under the just above half mark.

I know something is out of order because at highway speed, the air passing through the radiator should be enough for a good heat exchange, but the fan keeps coming on for long periods even at highway speed (abnormal for this engine to date). The hotter the engine runs, the lower my MPG is running. Down south, I have had to but gas with 10% ethanol in it. I know that reduces mileage so I tried a tank of 90 octane with no ethanol. Ran quicker, but still running hot a terrible mileage.

Today, I decided to try the first cheap thing and replace the antifreeze with a different brand (50/50 mix). I could see the new antifreeze was a little thinner viscocity than what came out. I am REALLY hoping that the slightly thicker antifreeze wqs just too think to provide a decent heat exchange. While filling, it burped a few times at the radiator cap and I was getting concerned about a potential head gasket issue. Or, is it possible the bakelite impeller pump was more efficient than the new metal impeller pump?

On Monday, we are packing up and heading 4 hours north in Florida so I get a chance to see if changing the antifreeze does the trick.

Fingers crossed for ya, Gerry! I've always wondered that about the water pumps...I would think that the design of the bakelite impeller would move more coolant than the steel one, like a well-designed propeller vs. a simple fan blade.

The shape did fill the space better & the swirl design just may have done a more effective job moving coolant.

If it's still running hot after changing the anti-freeze, i would say the thermostat is not working properly, but you would need to know the actual temp reading first of the thermostat housing while it is running to determine this. It could just be your Temp Gage getting faulty.

I've painted a lot of radiators, and that has never been an issue, or running the metal impellers.

Good luck to everybody making these trips, it is hot out there, and be safe.

hmmmmm...fla is one beast nowdays with the crappy gas and the humid always scorching heat adds alot for the oldwing to deal with ...the head gaskets wont take this kind of treeatment ...there simply way to much goo % verses metal substance....the whole idea of fan coming on at rpm is not a good story ...there should be no problem there ....maybe the radiator needs paint cleaned off fins some ...but also if head gasket is playing a part higher it could put pressure in the cooling system and slowing flow to the effected area or head ....i guess you seen the thread of jpwinger and how his bike got in trouble on the interstate travel down in fla ...i can also tell you that hooch suffers from none of this ... yes to me the colder the motor runs ...better the gas milage ....hooches motor runs really cool .. but there is no heat shield ...it dose have a thermostat... 1200s flow more coolant ... 12% more ...but the thermostat has the rivot gone and the hole inlarge a bit ...and hole is at the bottom ....my motor never comes no where near hot ....i have no gauge but i can lay my blue covered legs on the motor anytime i want....and do so at times while riding to just change possition ..i have no hiway pegs....on 1000s and 1100s it seems no thermostat works great the flow is slower on them and it seems to do good there with the mongrel bike i rode down there for yrs ...never blew a head gasket in fla but came close before i modified system to where i like them .....sometime the tech and engineering just dont line up with the best health for the motor ...i think this is one spot where this is entirely true ....be careful gerry ....

Took heat shield out and thermostat out now it runs what I think is very cool running temp's in Fl. Below operating temp line on heat gauge. Maybe need to take thermostat out. But that's a real hassle specialty on road. MY 80 is now floridaized. Jerry

Just as a rule of thumb:
I live and ride in the southeast coastal region of Texas, the temperatures and high humidity are nearly identical to Florida. (very tropical, ugh)

82 1100 Interstate with stock water pump and thermostat.

My bike runs typically when at speed on the first gauge detent or about 1/4 up from cold indication.

In heavy slow traffic or at long signal light stops it will climb to just above 1/2 way towards hot on the gauge.

It has never overheated or puked any coolant.

Interesting you say in the other thread, mpg went down and engine temp went up, hmm.

As far as the heat goes, I know you have the air deflectors on. Those ram air through the radiator. Fan should never come on at highway speed.

I would take a ride without the trailer to compare temps since the trailer load is the main difference here.

Dan beat me to it... what is the difference of running without the trailer in the same external conditions?

I have riden in similar conditions loaded down 2 up and camping stuff for 3 day trip and temps ran similar at 65-70, 55-60 temp would come down.

My strong opinion is the cooling system on these bikes are designed for a max load at best, just like cars. You load them down past that or close to it, then something has to give.
More cooling needed, lighten the weight load, lessen the engine load by slowing down, run the engine at its least loaded rpm and best torque.

One thing that jumps out at me is you got 41 mpg pulling the trailer at home.
Possibly it's running too lean with your load now.
How do the plugs look?

Just some thoughts I had.

Previous posters all make good points.
I should also say: My bike never pulls a trailer and being exclusively 1 up comes nowhere near max load capacity..

[url=https://classicgoldwings.com/forum/viewtopic.php?p=152103#p152103:tzv8s39h said:

Terry » Mon Jun 29, 2015 8:05 am[/url]":tzv8s39h]
Just as a rule of thumb:
I live and ride in the southeast coastal region of Texas, the temperatures and high humidity are nearly identical to Florida. (very tropical, ugh)

82 1100 Interstate with stock water pump and thermostat.

My bike runs typically when at speed on the first gauge detent or about 1/4 up from cold indication.

In heavy slow traffic or at long signal light stops it will climb to just above 1/2 way towards hot on the gauge.

It has never overheated or puked any coolant.

Click to expand...

Yep, that is my normal also.

Here is what we are going to do. Her Explorer has a trailer hitch also. We are going to buy a receiver that will fit my trailer and be prepared to transfer the trailer to her vehicle if the change in antifreeze does not make the difference. At least I can reduce the load if I absolutely have to. We are loading her Explorer to the hilt as it is and adding a cargo bag to the roof rack.

I called my mechanic buddy (who lives in Sorrento Florida and is where we are staying tonight) and he agrees the GM antifreeze is a bit different than Preston green. The viscocity is just a bit thicker and may not be passing through my radiator well enough. My radiator might also need to be dipped, but that isn't happening right now.

My only concern is blowing a head gasket!! :shock:

In a pinch the bike will run cooler with strait distilled water , if you need to get where you're going.

BTW, I checked the manual and the 10W40 should be OK for these temps and I have the correct coolant according to the manual. It also states that running the gauge in the white is OK, only in the red is it an issue. It ran in the high normal at the same level and never ran up to red, so maybe it is just the darn heat, humidity and load.

I'll find out in a couple of hours when we leave! :moped:

You probably know but if you resort to only water, coolant boiling temp is lowered so keep a close eye on it boiling out to the reservoir.
A higher pressure radiator cap would help but then more pressure in the cooling system could mean more chance blowing a head gasket.

If you have the time and tools with you. I'd try removing the shield between the radiator and motor to let more heat escape. It creates a rather large dead air space.

I just have a couple of thoughts, first being are you sure you got all the air out of it? Secondly the long life anti-freeze has been problematic in some of the older engines, at least that is what I have read. If you have access to a temp gun, check the cylinder head temp when she is hot and see what it says. Reason being mine began running hot, at least by the gauge but the sending unit was bad. The reason I mention checking the temp at the cylinder head, that is where most of your heat is going to be and where damage will occur if the engine is overheated.

If a engine is running hot the fuel mileage will always go down, reason being it there is a good chance you are getting pre ignition.

Sorry to keep anyone waiting, but the issue is solved!!! Changed the antifreeze and got rid of the orange stuff and the bike is running right back where it always ran before!! (Even in the hot temps down here in Florida!!) :yahoo: arty:

Boy am I glad it wasn't a head gasket!! I got to my buddies house in Sorrentino FL and we looked up the differences in the antifreeze's and sure enough, this stuff is a slightly heavier viscocity; too heavy to properly pass through the cooling tubes in the radiator. Turns out, it is heavier by design. Supposed to be for GM aluminum engines and it absorbs heat for a longer period with the intent of dumping the heat during the heat exchange. Of course, that requires a different size cooling system than our 1100's have. :cheeky:

I will never make that mistake again!! :yes: I am just thrilled the cooling system is now working exactly as it always did before and that the load from pulling the trailer is not the issue!! :clapping: