So iv been driving my coupe pretty regularly due to the nice weather. Going down the highway i noticed the temp was creeping up around 230 degrees with the fan going balls out. Even once off the highway it wasnt wanting to cool down. The fan pulls enough to suck a piece of paper flat against the front of the radiator, and i have a 160 degree miloden thermostat that opens at 160 ( i checked in a pan of water.) Im running straight water with a drop of dish soap to break the surface tension. This thing will not stay cool! Any advice?
marty, try a 50/50 mix of antifreeze using distilled water making sure your cooling system is totally free of air as trappe dair will cause overheating. what you also need is a remote thermal tool and check all areas of cooling system, large differences mean blockages.
It's called coolant for a reason !!!!!! <table align="center" border="1" cellpadding="3" cellspacing="0"><tbody><tr><td> </td> <td>Pure Water </td> <td>50/50 C<sub>2</sub>H<sub>6</sub>O<sub>2</sub>/Water </td> <td>70/30 C<sub>2</sub>H<sub>6</sub>O<sub>2</sub>/Water </td> </tr> <tr> <td>Freezing Point</td> <td>0 C / 32 F </td> <td>-37 C / -35 F </td> <td>-55 C / -67 F </td> </tr> <tr> <td>Boiling Point</td> <td>100 C / 212 F </td> <td>106 C / 223 F </td> <td>113 C / 235 F </td></tr></tbody></table> Seriously though, do you have a fan shroud on it? Is it an electric fan or a belt driven fan? If electric, which side of the radiator is it mounted? if it doesn't have a shroud on it, put one on it! Why spend hundreds of dollars on a radiator and not complete the assembly?
Electric or mechanical gauge? I've seen way too many electrical temp gauges read wrong. Make sure that the gauge is reading correctly before you do anything. What engine? and if it is a small block Chev does it have the correct water pump for the belt system that is on the engine? That is a pretty common issue especially if you are mixing and matching pieces. I had to Google the dish soap in the cooling system and although I had never heard of it there are some guys who think it works. I can't see any advantage to running a street car without a 50/55 percent antifreeze in it even if you don't intend to drive it in cold weather. That looks like a real good way to end up with a cracked block the one time you put off draining the cooling system in the late fall. It's been 50 years since guys drained out the antifreeze in the spring and put plain water in the system but that was more due to the antifreeze during that period in time breaking down over time than the water working better to cool the engine. Their engines also boiled over on a regular basis during the summer and almost all mountain pass roads had water barrels along the way in those days for guys to dip water out of to refill the radiators. Just because granddad did it back in the day doesn't make it practical today with the products we have today. I'd check the condition of the radiator including making sure that the fins weren't plugged with bugs or dirt. You probably need to have it flow tested too to see if it will flow enough coolant to actually cool the engine. I'm not sure which coupe is yours but I think I remember seeing one at Billetproof that had an aluminum sheet grill insert with holes drilled in it for air flow that would probably block about half the air that the radiator needed to cool an engine. Make sure that you haven't created a problem by installing something that is supposed to look cool but doesn't allow the engine to cool properly.
a little more info also,type motor,new problem/did it cool before new rad,old rad? also put a new gauge on it first.
What he said /\ / \ | | What's the full story here? Before you mess with anything else, Check your timing! Make sure your distributor is advancing properly and you have a good inital setting. Not enough advance makes engines run HOT.
All of the things above were right on, with the antifreeze. I would use a product called wetter water. There is other products like it. I was surprised the only change I made was adding the wetter water and it made a big difference it made the normal running temp go down and highs were lower to. It is not cheap, but it really worked. I had good result in a car that would overheat in hot in town driving. This would run cool out on the highway, but as soon as you got to stop and go traffic the temp would climb.
1. Shroud...not matter how 'cluttered' or uncool they look...they're important, and try to get your fan at least half way into the shroud. 2. 50/50 or close to it all year round... 3. Correct radiator cap...pounds could be too low, preventing the system from 'keeping' the water in the system...but...too high and the system may not like that either. 4. Burp the system...you get a pocket of air in there...it'll warm up real quick. I pop off the rad cap...start it up and let'er run until the pressure builds slightly...then grab the throttle and rev it a bit in small burst. The bubbles will make their way to the rad cap hole...DO NOT RUN IT HOT!!! SERIOUSLY! 5. Timing...'tarded' timing could cause a lean situation...causing it to run warm? 6. Flush the Radiator...maybe even take it to a reputable shop to pressure test it...maybe cost you $15? 7. Oil weight? I know some guys will run 5w30 in the summer...on an older engine where the tolerances may be a little big (wear & tear)...10w30 works fine all year round? 8. Pull the water pump and flush the water jackets...you'll be surprised what crap makes it way out with a little spray from a hose. Good Luck!!
Water Wetter is better suited for usage where Coolant is not allowed (Motorcyle Racing- we're not allowed to use coolant on the track.), however, it does work...Royal Purple has a product out called Purple Ice...I've heard rumors where people have noticed as much as 15 degree temp drop? However, it's $18-$20 a bottle...worth trying???
Before anything, I'ld get an infrared temp gun and check the actual temp at the thermostat housing. My model A reads 220 on the gauge when the actual temp measured at the housing is 180.
Thanks for the replies guys. Yanked the radiator out and cleaned it best i could with a garden hose. Little bit of rust but nothing major. Popped the thermo and flushed the block real well. Replaced the rad and hooked it up. Also rewired the electric fan. Used some of that Dexcool antifreeze that GM uses now, mixed it 50/50. Also i dug out the hole saw and cut 6 2-3/8ts holes in my grill to get more air flow to the rad. I think i got it solved. Will find out more tomorrow. Mr.48chevy, i have the green 1941 Nash coupe with 28 on the door. Motor is a SBC, 4 core rad, short water pump. 160 miloden thermostat with a 1/16th hole drilled in it, 13 pound cap, mallory dual point, 15-40 oil.
If it overheats at stop lights a low speed it is a fan or water pump speed problem HOWEVER at 50 to 60 MPh the fan has nothing to do with it . That is usually rad too small for the high HP engine. (or partially blocked. ) In 40 plus years at this I never saw a car go from over heating to not overrheating by switching to antifreeze. Not that a borderline case might do that but it is highly unlikely. Pressure cap is important as it keeps coolant from turning to steam. Every pound of pressure raisies the boiling point 3 degree F (water). Ie a 13 lb cap will buy you 39 degress F extra protection . or a boiling point of 251F That said 230 is too hot . 180 is max I like to see. More rad I think is what you will have to do. Swallow hard and get a big one. A year from now the pain will be forgotten. It took a bit but my Max wedge now runs at around 160F. It might get to 170 but that is about it. I drove it yesterday and it was 34 degress C whatever that is here with not so much as a whimper. (28C is 82 F so it is mid to high 90s ) Mike is all bent out of shape because his early Hemi in the Willys hits 200F after a hard drive in this weather but it has little or no pressure.(no pressure cap) He is working on that now. All part of sorting out a new combo. You will get through it. Dont be discouraged. Don
Agreed, water cools better than antifreeze, and that's a scientific fact. Don't let anyone tell you otherwise. Also correct, if it's overheating going down the highway, it has nothing to do with your fan. At those speeds your fan is just "in the way" of air passing through the radiator. +1 on checking your gauge against a known temp reading, many gauges are not exactly accurate. Like I said above, check your timing to make sure it's got enough advance at the RPM you're noticing the overheating problem. If it's retarded, then it's burning the mixture on its way out of the exhaust port. The energy that's coming from the combustion of that fuel is going toward heating the block/coolant/exh. manifold instead of making power in the combustion chamber.
Not to confuse or change this thread but,Dolmetsch,you said your Max wedge runs around 160F,i am confused by this because on another thread i was told that when running to low of temp in the motor causes condensation in the motor and does not get burned off and causes sludge,and i was told to run at about 185 to 190.Any thoughts on this..
And this is where we disagree, I shoot for 180-190 as operating temp. Though the factory said 190-220 on the 401/425 Nailheads. To cool and you don't make as much power either, and that is a fact.
Small block Chevy V8's are easy to cool except the 400 block. That takes a whole bunch of mods to stay cool in hot weather.
This sounds like it is a new development. If so, I'd do a good flush to start with. As the others have stated heating up while cruising usually indicates a partially clogged radiator. A cheap infra red thermometer is a great tool for checking for consistent temps across a radiator. If you find a few tubes that are cooler than the rest then you know it needs to be cleaned which might mean removing the tanks. They used to be pricey when they first came out but for 50-60 bucks they can tell you a lot about a running engine. We used them to diagnose cat converters and cooling systems.
"Mike is all bent out of shape because his early Hemi in the Willys hits 200F after a hard drive in this weather but it has little or no pressure.(no pressure cap) He is working on that now. All part of sorting out a new combo. You will get through it. Dont be discouraged." THIS NEWS JUST IN! From the gartage floor of realtime experience. As i mentioned early this morning Mike with the hemi powered 41 Willys was all bent out of shape because his Willys would hit 200 after a hard longer run (about 20 to 25 minutes. It would puke water or coolant as soon as he pulled in the driveway. Mike will not go to a car show when it is doing this . Last night I took my Stant pressure check kit down to him but he hadnt done anything by breakfast this morning. Still depressed he talked about phoning Speedway and spending 5 to 600 $ for a new rad. Again i repeated what I had said this morning and told about your problem of running at 230F. When we came back from our secret Auto wreckers later i went in his shop with him. I took my Stant tester out of the box and tested his rad cap. It held zero pressure. I then istalled it on his rad which has some sort of a pressure release of unknown value. The value is less than a pound i discovered. I took the rubber spacer out of my testor box and popped it in the top of the rad. Mike grabbed his caliphers and measured the depth. I took a spare rad cap (7 lb) out of my pocket i had brought and he measured that it was just a bit too short (060"). A few minutes later we found a piece of flat rubber and shimmed it. The cap intalled properly with pressure on the spring ??? I dont know how much. We were just testing. Mike pinched off the line from the relief for a quick test, valve with a small pair of visegrips. I drove home a few miles away and told Mike to drive to my place just in case it didnt work he would not cook his engine. He took the long way which last week (much cooler weather then)would put him at 200 by the time he pulled in. He pulled in today and announced he CAN NOT get it over 150F . We left it sitting for 20 minutes to see if it would try and puke from the heat soak. It did not. He left .I ate lunch. later after a cool drink i went outsde to go to the garage just in time to see Mike cruising by again. About ten minutes later he phoned. I was nervous as I really wanted it to work. In typical Mike style he complained. "I KAN NOT GET IT TO GO OVER 150F . I have been driving it all around since I left your place. I had it fast on the highway and slow through the village. I drove it around the lake too. it will not overheat. When I got home i let it sit . Nothing no puke. It never went above 150. " It is today a heat wave. A record for us here. On my house thermometer I just checked it is reading 93F in the shade. So there you are. A real life solution on a real hot car on a real hot day. The sceince of cooling systems is often overlooked in the heat of the moments. Bigger, better, louder, longer, is always the tempatation but it never hurts to sit down and think the deal through. How does it work and what part of that are we missing perhaps. Luckily the laws of Physics never change. I post this in the hope that someone else in a similar situation to Mike might find also a solution , a permanet solution to their problem. The reasons take too much space to explain in this post but Mike is happy. Perhaps one of you or a friend will find this helps you too. Don
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