Mmkay, now I'm angry!
08-30-08, 10:50 AM
#26
To clean the condensor or rad core, just spray on some good tough degreaser like eitehr engine degreaser or a chemical such as silicone wax remover, let it soak, and gently pressure wash the core out till there's no more gunk. Be careful not to use too much pressure as you can bend the fins pretty easily, you mostly just want to use it as an aggressive rinse.
Clutch fan suggestion is excellent....
Clutch fan suggestion is excellent....
08-30-08, 12:50 PM
#27
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Sometimes running w/ no t-stat can cause overheating problems, as the coolant doesn't stay in the radiator long enough to cool properly. In other words, there is too much flow in the system. I bet putting a OEM t-stat in will fix it.
08-30-08, 01:10 PM
#28
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In addition to the above remarks about how coolant flow rate impacts heat transfer another important point to consider is that these cars have a bypass thermostat. What that means is that when the thermostat is closed the water pump is circulating coolant around the inside of the engine to keep temperatures inside the engine even (this is because combustion events always occur in a specific part of the engine instead of being distributed evenly throughout the engine like in a piston engine). When the thermostat opens the path that the coolant takes through the engine changes to include the radiator as part of the loop. If you have no thermostat in place then there will be insufficient coolant flow through the radiator, as most of it will just continue to circulate through the engine/heater core.
In cars with a non bypass setup the thermostat stops the flow of coolant altogether except for a what is running through the heater core.
The fact that you had a garden hose between the engine and heater would only impact the performance of the heater.
Last edited by JM1FD; 08-30-08 at 01:14 PM.
08-30-08, 02:40 PM
#29
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Wrong. The thermostat is a restriction to the radiator. coolant will always take the flow of less resistance, removing that will not make the flow to the rad suffer at all.
08-30-08, 04:43 PM
#31
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The thermostat is not merely a restriction to the radiator. It also alters the coolant path. That's what the little disc on the bottom of the thermostat is for....it covers up the bypass hole to prevent coolant from looping through the block and bypassing the radiator.
08-30-08, 06:33 PM
#32
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I should rephrase what I said, the thermostat restricts flow of coolant coming out of the engine. Without it, the coolant flows through the engine and back into the radiator too quickly. So, not only does the coolant not stay in the rad long enough to cool properly, it also doesn't stay in the engine long enough to absorb enough heat to cool it down. So it becomes a viscous cycle that slowly allows the engine to overheat. It cools down when it drops to idle because the water pump runs slower and the coolant circulates at a slower speed.
08-30-08, 09:37 PM
#33
Well, I picked up the fan shroud and a good clutch fan tonight. The undertray that my friend said he had doesn't actually exist... So once the t-stat gets here I'm going to install that. And by that time the fan clutch and shroud will already be in. It should be enough to solve the problem. I know people who run without undertrays and it's alright, so it'll work for now. An undertray is definitely on my list though.
08-30-08, 09:49 PM
#34
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an Undertray will actually make a difference,in your case.The Efan may be sucking air,but once you get Going,it isn't being directed TO the engine..The Air from under the car Redirects it.The undertray will Stop the Air from Getting Bashed all over the engine bay,So the Efan can Suck it's air and the Underside Turbulence won't Take the air that is Supposed to be Going to towards the engine and Blow it all over..a shroud wouldn't hurt either But,you have an Efan..An OEM thermostat is a Bonus..(I swear by them..NOW..I have a Koyo installed,Just recently..I get 84 degrees Celcius Constant..and I Haven't Installed my Tray..as I wanted to check the cooling systen for leakage before Reinstalling it.)
08-31-08, 05:22 PM
#39
I can't believe that no one jumped on the fact that the undertray is missing.
I can guarantee you, almost 100%, that the missing undertray is the sole cause of this problem. If you don't have the undertray then not much air will go through the radiator. I don't care how big of an e-fan you have, it won't come close to the flow of air that driving will cause. The fan is only used when moving at slow speeds.
Since the car is cooling just fine when idling, then you don't even really need the fan shroud, but it is a very good idea to get it, especially if it gets hot outside there.
Just so you know, this post isn't just based on logical thinking, but on actual experience. I recently replaced my rad. I didn't want to put on the undertray until I verified that everything was installed correctly. The temps just kept on rising and rising, then went down once I stopped. When I put the undertray back on, my temps were at rock solid 185, and that's in over 100 degree weather.
Also, FYI, the heater hose runs in parallel to the rest of the system. You could block of the hoses and the only thing that would happen would be that the heater wouldn't work.
Edit: Here's Aaron Cake's cooling troubleshooting page. It basically says the same thing. http://www.aaroncake.net/RX-7/cooling.htm
I can guarantee you, almost 100%, that the missing undertray is the sole cause of this problem. If you don't have the undertray then not much air will go through the radiator. I don't care how big of an e-fan you have, it won't come close to the flow of air that driving will cause. The fan is only used when moving at slow speeds.
Since the car is cooling just fine when idling, then you don't even really need the fan shroud, but it is a very good idea to get it, especially if it gets hot outside there.
Just so you know, this post isn't just based on logical thinking, but on actual experience. I recently replaced my rad. I didn't want to put on the undertray until I verified that everything was installed correctly. The temps just kept on rising and rising, then went down once I stopped. When I put the undertray back on, my temps were at rock solid 185, and that's in over 100 degree weather.
Also, FYI, the heater hose runs in parallel to the rest of the system. You could block of the hoses and the only thing that would happen would be that the heater wouldn't work.
Edit: Here's Aaron Cake's cooling troubleshooting page. It basically says the same thing. http://www.aaroncake.net/RX-7/cooling.htm
09-05-08, 11:01 PM
#40
Alright, so I got the t-stat and all.
-New Mazda T-Stat
-Good Clutch Fan
-Fan Shroud
-Under Tray
-Bled Coolant System
The temperature reaches half on the gauge after you start to drive it and pretty much stays there.
Any other thoughts?
-New Mazda T-Stat
-Good Clutch Fan
-Fan Shroud
-Under Tray
-Bled Coolant System
The temperature reaches half on the gauge after you start to drive it and pretty much stays there.
Any other thoughts?
09-06-08, 12:54 AM
#41
I should rephrase what I said, the thermostat restricts flow of coolant coming out of the engine. Without it, the coolant flows through the engine and back into the radiator too quickly. So, not only does the coolant not stay in the rad long enough to cool properly, it also doesn't stay in the engine long enough to absorb enough heat to cool it down. So it becomes a viscous cycle that slowly allows the engine to overheat. It cools down when it drops to idle because the water pump runs slower and the coolant circulates at a slower speed.
Let's say each water molecule is a dump truck- insert Ted Stevens joke here- and as it passes through the block it picks up a load of heat which then gets dumped in the radiator. Remove the thermostat- which speeds up the process- and yes, less heat is absorbed and less is dumped BUT the truck is making more trips for any given amount of time so the end result is the same.
Besides forcing a quicker warm up and regulating the temp (the thermostat is always varying it's aperture depending on temp) the other function of the thermostat is to function as a restrictor in the loop- not to "hold the water in the rad longer" but to prevent cavitation.
The cooling system is designed with a certain amount of backpressure in mind- remove the thermostat and the flow dynamics change and cavitation, which is not only death on the pump but leads to decreased coolant efficiency, occurs.
That's why race cars- which typically run only at elevated RPMs (and thus, faster waterpump speeds)- underdrive the pump with a larger pulley.
/rant
09-06-08, 10:34 AM
#42
My S4 TII will stay at about 1/3 the stock gauge cruising around not beating on it.
If the temp is staying consistent, don't worry about it - just keep an eye on the gauge.
09-06-08, 11:37 AM
#43
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Fail... try again?
Now, I'm not saying all cars will overheat just because they have no t-stat, I have run several w/o them w/ no problems. But city driving and extended high-speed driving (ie long highway trips) can cause abnormal raises in temps if there is no t-stat on certain vehicles, depending on conditions and the condition of the cooling system parts.
When I got my Diplomat, it had no t-stat, and on a trip to Florida, the temp gauge climbed slowly from just off cold at the start to 3/4 gauge in 350-400 miles. In normal driving, it would never get off just over cold. Now w/ a 195 t-stat, the temp comes up to 1/2-gauge and stays there.
09-06-08, 11:42 AM
#44
When 1/4 is normal, 1/2 for me is too much. My other GXL gets to half when I've been on it for more than a few minutes, and it always cools right back down again. I am going to be borrowing a thermometer to check the coolant temp soon. I'll post again after I've flushed out the system and run the numbers.
09-06-08, 02:11 PM
#46
Well in the beginning I was reluctant to flush the system because the coolant in there was green and clean.
But I then remembered my other car... When I bought her, she was sitting in a field. All of the coolant, which had to have just been water, had disappeared. So I filled her back up with water. I can't remember why I hadn't done a flush right away, and I don't believe there was any reason other than sheer laziness. The side effect of this was that she ran at just below half to half driving around AND idling. Finally, I did a half *** flush that wasn't really a flush at all. I simply drained the radiator, ran the garden hose thru it until it ran clear (And god was it dirty!) and refilled the system. Viola, the problem went away and I'd had perfect temp. up until a friend of mine and I did a REAL flush. Of course all that did was make sure everything was clean.. It's been a long while now and I've never had a temperature issue with that car...
Now onto the new car..
So today I stopped by the parts store and picked up some Prestone radiator flush and I've been working on that for a little while now. At first, when I drained the radiator and the block, the coolant was clean and green like I said in earlier posts. But the moment I stuck my hose in it and let it run...the leftover green color instantly turned brown and started flushing nasty crap out of the radiator. So I poured the flush crap into the rad and ran the car with the heater going for about 15 minutes. Now I'm waiting for it to cool down a little bit before I drain the rad and block again, fill the system back up with plain water and drain it once more. After that, I will refill the system properly...bleed it...and go for a drive.
With any luck, this WHOLE problem has just been a badly clogged radiator. We will see. Once I am done and I go for a drive I will tell y'all how she did. Wish me luck!
But I then remembered my other car... When I bought her, she was sitting in a field. All of the coolant, which had to have just been water, had disappeared. So I filled her back up with water. I can't remember why I hadn't done a flush right away, and I don't believe there was any reason other than sheer laziness. The side effect of this was that she ran at just below half to half driving around AND idling. Finally, I did a half *** flush that wasn't really a flush at all. I simply drained the radiator, ran the garden hose thru it until it ran clear (And god was it dirty!) and refilled the system. Viola, the problem went away and I'd had perfect temp. up until a friend of mine and I did a REAL flush. Of course all that did was make sure everything was clean.. It's been a long while now and I've never had a temperature issue with that car...
Now onto the new car..
So today I stopped by the parts store and picked up some Prestone radiator flush and I've been working on that for a little while now. At first, when I drained the radiator and the block, the coolant was clean and green like I said in earlier posts. But the moment I stuck my hose in it and let it run...the leftover green color instantly turned brown and started flushing nasty crap out of the radiator. So I poured the flush crap into the rad and ran the car with the heater going for about 15 minutes. Now I'm waiting for it to cool down a little bit before I drain the rad and block again, fill the system back up with plain water and drain it once more. After that, I will refill the system properly...bleed it...and go for a drive.
With any luck, this WHOLE problem has just been a badly clogged radiator. We will see. Once I am done and I go for a drive I will tell y'all how she did. Wish me luck!
Last edited by Acesanugal; 09-06-08 at 02:20 PM.
09-06-08, 07:46 PM
#49
I'm very happy to say that the motor is fine now. I even took it out for a bit of a drive and got her up to 60mph and drove like that for a bit...temp didn't even budge! I got on it...still didn't go higher than 1/4. Bizzare, but I'm satisfied.
Next on my list is the water treatment followed by some seafoam action to see if I can ungunk the innards of the motor and get some better compression test results...
Next on my list is the water treatment followed by some seafoam action to see if I can ungunk the innards of the motor and get some better compression test results...
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