Coolant Temp-Hot or Not? (Thread split from "Water pump/front cover" thread)

AApple":39rz176h said:

I'm moving posts from my Water pump thread to here, since the discussion has gone towards talking about coolant temps, and ways to make it run cooler. Just seemed like a new thread/discussion was appropriate. :mrgreen: :laptop:

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I use 50/50 Prestone from Walmart, says no sillicates on back. I use distilled water to flush with, no chemicals in it, and a lot cheaper.

Joel, have you installed a new radiator cap lately. This seemed to help my 30 year old one.

Otay...I measured my coolant temp when I got home today. The gauge was past 1/2...closer to 3/4 by the time I got parked, and checked the temps. On the lower housing, where the hose goes into the pump, the temp was right at 200*. At the thermostat housing, and the elbows coming out of the tops of the heads, the temp was around 218-220*. That sounds kinda warm, to me. Is it? Are there any published specs on coolant temps, compared to gauge readings? Once it cooled down, and the fan went off, with the gauge at 1/2, it was still showing 190 on the lower housing, and 200 on the head outlets. Problem is I don't know what's too hot, or normal on one of these engines. :heat:
I did realize that I had NOT used my original temp sending unit...I used the one that came with the t-stat housing I bought. I used it because I wasn't sure I would be able to get it out of the housing without breaking either the sender unit, or the housing.
Now, I really wanna install a mechanical temp gauge....

Fitz2at":23jbeqzp said:

Joel, have you installed a new radiator cap lately. This seemed to help my 30 year old one.

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No, I have not. I have the original cap on it. Might be time for a new one, even if it appears to be working normally....ya never know. Thanks for the idea, tho... :thanks:

Maybe - maybe not. Of course when you shut it off the coolant stops circulating, things will heat up pretty quickly. Cooling things down with 105+ degree ambient air passing through the radiator ain't gonna be an easy thing to do. I'd wanna see at least 160*, and absolutely no more than 220*-225* max. 260* is too late. One thing I learned when I lived in Phoenix for a year, you gotta seal that system up really tight. Hose clamps, o-rings, gaskets, etc. I even had to put a 22lb radiator cap on my 13lb system before the temp would stabilize and hold the coolant in. You got a new t-stat with a gob of holes drilled in it, so that's likely not a problem. What temps are you getting across the radiator? At idle in the cool morning after a cold soak, how long does it take to reach the max operating temp - and will it pretty much stay within an expected range throughout a couple fan cycles? How will it do the same way in the hot part of the day? The hottest coolant will be at the top coming from the motor. That's where you want to measure temp. And how does that compare to the bottom where it's going back into the motor. Measure this while the fan is still running. As you already know, a mechanical gauge with a sensor that actually touches the coolant will be the most accurate temp measurement, but you will only get a reading at one spot. I'd offer to measure the temp across my radiator for comparison, but I'm at sea level pulling 70 degree ambient air through the fins.

Thanx Ron. I checked this with the engine still runnin when I pulled in last nite. The gauge was higher at that time than it is while runnin down the road, since it was idling, and not moving. The temp does not seem to go any higher while riding than just past 1/2...maybe the width of the needle past center. Once I pulled into the garage, it went aboot halfway between center, and the beginning of the red zone...so prolly 3/4, maybe a little less.
I figured 220* was prolly pretty much at the high end, too. The radiator was cleaned when I had it off. Flushed both directions with solvent first, to get some of the oil residue out, then into the parts washer w/190* soap/water solution, then flushed both ways with clear water. I don't think there is a restriction there. I'm just wondering if this thing has always run at these temps, but maybe the other sending unit was just giving me a different reading on the gauge.
It does not seem to get any hotter in traffic with 100+ deg. ambient temps, either, so that's kinda good. The gauge stays pretty steady once it gets to just past 1/2 mark. I'll do a little more temp mearuing and see what I come up with.

How is it in the mornings run to work?
You should see much lower readings, below 1/2 gauge for sure if its reading right.

Those temps with the gun sound close to to what I was getting.

Morning run, in 82-4* temps, when I got here this mornin, I saw 197* at the head outlet, and 184* on lower pump inlet from radiator. Funny thing, if I shoot the radiator itself, the temps are MUCH lower...in the 140-150* range. This with the gauge at just past 1/2. All these readings are with the engine still idling after the 46 mile ride @80mph. After I exit the freeway, I only have less than a mile to the shop, with no traffic, and only two lights that don't stay red very long.
It doesn't smell hot, it still runs great, fires right up when hot. I even shot the head itself, close to where it meets the engine block, and only got a 200* reading. Maybe I'm just looking for more problems that aren't really there, but it still kinda worries me a little.

AApple":29vq1sec said:

Morning run, in 82-4* temps, when I got here this mornin, I saw 197* at the head outlet, and 184* on lower pump inlet from radiator. Funny thing, if I shoot the radiator itself, the temps are MUCH lower...in the 140-150* range. This with the gauge at just past 1/2. All these readings are with the engine still idling after the 46 mile ride @80mph. After I exit the freeway, I only have less than a mile to the shop, with no traffic, and only two lights that don't stay red very long.
It doesn't smell hot, it still runs great, fires right up when hot. I even shot the head itself, close to where it meets the engine block, and only got a 200* reading. Maybe I'm just looking for more problems that aren't really there, but it still kinda worries me a little.

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Both of these readings are very close to what I got.
I think the temp sensor is flakey.

Does anyone know of a mechanical gauge set-up that fits the threads on the t-stat housing for a 'Wing? I sure would rather have one, if they make one. I guess I could take my old housing, and do some checking to see if there is anything out there with the same threads, that is short enough to fit in there without restricting coolant flow.....time for some research. I would also like to install a mechanical oil pressure gauge, but that ain't much of a challenge...pretty straight forward on that.
So far, I've put around 300 miles on it since getting the water pump/head gaskets done. The turd is no longer marking it's territory everywhere I park!! Yippie!

Gauge or sender could be flaky. I would think any metric thread sender and mechanical gauge would work as long as the capilliary isn't too long. Could also keep it electric, no shortage of gauges available for 12 volt systems.

I can check my radiator with my infrared gun when I get home. As a matter of fact, I did the same testing on the '81 engine and then the '83 engine to be sure the water pump and radiator system worked plus I was verifying t-stat opening and closing temps. I have to check, but I think I posted those numbers here somewhere.

im hoping to get there with the 77 :smilie_happy: :mrgreen:

I think the cap tube type temp gauges are too long, at least the cheapy one I have is to work.

honda wiring ...just loads of fun .... :swoon: :cheeky: :mrgreen:

Ahhhhh.....here is that post:

have checked my radiator, pump and thermostat housing for temps witha thermo gun. The T-stat opens at 205 degrees at the radiator (195 degree t-stat) and does not close until temps get back down to 189 degrees. You could put in a manual gauge from a parts store in to check temps.

With the t-stat in and an outside temp (like today) of 60 degrees, my temp gauge will go to 1/4 after first warming up and up to 1/2 when fully warmed in stop and go traffic. Out on the highway, it drops to just above 1/4. Cannot emphasize enough the importance of the radiator deflectors to keep the engine cool at speed. When mine were missing, it ran up to 3/4 gauge on the highway with the fan running! Installed the deflectors, removed the chrome radiator grill and installed an OEM radiator rock guard instead and it never runs over 1/2 gauge!

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viewtopic.php?p=37403#p37403

You mention the deflectors. All I have is the fairing lowers for that, but...in the process of doing all this work, I seem to have misplaced one of the rubber seals that fit on the lowers, to "Seal" against the rad. Not that they fit all that well to start with, but I wondered to begin with if that was going to effect anything. I may need to look a little harder to find the seal, and install it, or just put some weatherstrip up there to direct the air thru the rad. I have often considered making my own "dam/scoop" to put on the bottom of the rad, even before this issue came up. I have the big, gawky Rolls Royce rad grill..it was on it when I bought it, but...this thing never ran as hot as it appears to be before. I think the issue may just be the different sending unit. I'll get something to fix the faring lower deal first, and see if that does any good, and go from there...I guess.
:thanks:

Any chance of just swapping out your sender with your old one? I still have the one from the '81 that worked same as the '83 if you need one.

I found that RR grill really made my radiator run hotter. I swapped it out with an OEM rock guard and it made a world of difference!

https://classicgoldwings.com/forum/viewt ... 845#p11845

https://classicgoldwings.com/forum/viewt ... 526#p13526

I tried to get the one out of the "new" housing, but it was pretty tight, and I dint wanna chance breaking something ELSE, so I just left it in there.
I think I can build some aluminuminum "wings" to fit along side the fairing lowers as extensions, of sorts, and also at the bottom of the rad as a "scoop". Might be able to shove a little more air thru there. For now, I think I'm just gunna ride, and not worry so much about the gauge reading. I'll tinker with it some more this weekend.

I agree...ride!

Question?.....did you change the t-stat? If you did, is it OEM or equivelant? (Dumb question next) Is it installed correctly?

When I read that last line about temps staying up while riding (at 80 MPH), kinda says to me......bad sender, or t-stat is holding the water at higher temps. Riding at 80 MPH (with the fan off) should have been enough to drop the gauge to middle and keep it there with high ambient temps.

NOT....I am such a dummy!!! I just reread your post about your in and out temps (maybe I should read better and keep my mouth shut longer!) Those temps are fine and 200 degrees on the engine/heads is correct! Sender is more than likely bad!

yes watch joel dont let get away from you :whip:

mcgovern61":2i1jzxx7 said:

Question?.....did you change the t-stat? If you did, is it OEM or equivelant? (Dumb question next) Is it installed correctly?

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No dumb kweschuns here... k:
I used the same t-stat that was in the engine before. It checked out operationally. I did drill a few small(1/8") holes at the top, next to the original bleed hole. It is installed properly....facing the correct way, and turned to fit into the slots on the housing. I could not see any degree numbers on it, so I can't say what spec it has, as far as opening temp. But....it was working fine before.

I'll definitely keep an eye on the temps each time I park it, to see if they are pretty consistent.

:whistling: If only I could convince someone here to disconnect their fan, and run the engine until the gauge pegs all the way HOT, and then take a temp reading with an infrared gun....then I would know just how hot it has to be to be dangerous...... :blush:

:smilie_happy: :mrgreen: :smilie_happy: