ChuckM Posted July 19, 2022 Share Posted July 19, 2022 I’m a first-time 7 owner, I bought my car in March 2022 and have been doing a fair amount of repairs to include tires, shocks, springs, clutch cable and a high output radiator fan (1460 CFI) to name a few. One thing I can’t figure out is why the car still runs hot especially went I push it? I think the previous owner removed the thermostat, so that’s not something I can experiment with, fan belt looks new, there’s a minor fluid leak which might be the water pump, but I’m not sure. I don’t think it’s a head gasket issue so I’m thinking water pump? Any sage advice would be appreciated, thanks. Link to comment Share on other sites More sharing options...
ashyers Posted July 19, 2022 Share Posted July 19, 2022 Chuck M., When you say hot, how hot? I'd caution you against removing the T-stat. It reduces the local pressure in the block and head which can lead to steam pockets forming and overheating. In addition running an engine cold for excessive periods is bad for both efficiency and the rings. Have you pressure tested the both the system and the cap? For every 1psi of pressure in the system the boiling point will increase ~3deg F. Something as simple as a bad rad cap can lead to a bunch of headaches. Andy Link to comment Share on other sites More sharing options...
ChuckM Posted July 19, 2022 Author Share Posted July 19, 2022 Andy, The temperature gauge is in Celsius, there’s a 90, then a hash mark (not quite half way to 140) then 140 Celsius. It warms to 90 C then creeps up to the hash mark, that’s when I head home. There are several things that might contribute to the problem such as air in the cooling system, bad water pump or old Marston radiator. I’m open to suggestions and recommendations. I am not a professional mechanic! Thanks Link to comment Share on other sites More sharing options...
MV8 Posted July 19, 2022 Share Posted July 19, 2022 Did the car have muddy coolant when you got it? What model fan did you install? A few pics would be great. Link to comment Share on other sites More sharing options...
MV8 Posted July 19, 2022 Share Posted July 19, 2022 The copper brass rad is serviceable, but radiator shops that can do the work are few and far between and the cores are more than a new aluminum radiator. All radiators collect sediment in the lower tubes that will eventually clog more and more of it. You can check during warm up by hand, feeling the core for uneven temps. Back flushing is about all that can be done on the newer radiators. Link to comment Share on other sites More sharing options...
MV8 Posted July 19, 2022 Share Posted July 19, 2022 If there is rust, it can insulate the jacket reducing thermal xfr, damage the pump seals causing a pump leak, clog the tiny holes in the head gasket, and block rad passages. If rusty under the water neck, I'd use evaporust thermocure and water for a week with no other changes, then thoroughly flush with water, replace the pump, install a 180 stat, back flush the old radiator, then refill with 50/50 standard green antifreeze (no "long life" coolant). If it still runs hot, replace the radiator. Link to comment Share on other sites More sharing options...
ashyers Posted July 19, 2022 Share Posted July 19, 2022 ChuckM, Before you go too far down the rat hole, you may want to verify the readings on the gauge. If you have an IR thermometer that makes it pretty easy and you can check the flow through the rad too. Check to see if the rad's fins are brittle. When they get to that point the fins no longer pull heat from the tubes and you get a situation like you describe and the core is shot. Andy 2 Link to comment Share on other sites More sharing options...
ChuckM Posted July 19, 2022 Author Share Posted July 19, 2022 Andy, I do have an IR thermometer so I’ll try that tomorrow. The radiator is not leaking or hissing so it could be a faulty gauge. Brilliant! Link to comment Share on other sites More sharing options...
ChuckM Posted July 20, 2022 Author Share Posted July 20, 2022 Andy, A picture of the fan and radiator, this fan has 10 blades and generates 1450 CFM. Link to comment Share on other sites More sharing options...
MV8 Posted July 20, 2022 Share Posted July 20, 2022 The derale 16212 is a great fan. I have the same one on my geo tracker with a s10 v6 driveline swap. It looks like you have the red wire capped and are only running power on the grey wire. It is a two speed fan. In order to get high speed (1450 cfm), both positive leads must have power to pull the full 21 amps versus 15 amps and 1000 cfm. Obviously, it would be a lot more effective direct mounted behind the radiator. It would be tough to make efficient baffles/rubber ducting behind it with everything in the way plus it is partially blocked at the bottom. If you turned it 90 deg it would help. The good news is that fan is powerful enough to be used by itself with no engine driven fan if you can get it close or direct mount. How did you know my name was Andy? (I'm kidding! I'll stop "helping" now.) Link to comment Share on other sites More sharing options...
ChuckM Posted July 20, 2022 Author Share Posted July 20, 2022 Andy, Your name appears when you respond to my post? This is a 2 speed fan, but when I connect the red wire to power I do get both low and high speed cooling, but the fan continues to run after I turn the ignition off? Obviously auto electricity is not my strong suit! Link to comment Share on other sites More sharing options...
MV8 Posted July 20, 2022 Share Posted July 20, 2022 I think you are talking to me. I'm Steve. Whatever you are connecting the red wire to has power when the key is off so not good. Can you take a picture of the front of the engine and back of the radiator area? Do you want the fan to come on automatically, with a toggle switch, or both independently since it is a two speed fan? Do you have a spot for an extra temp sensor on the engine or radiator? Link to comment Share on other sites More sharing options...
MV8 Posted July 20, 2022 Share Posted July 20, 2022 (edited) I went ahead and made a diagram as if you had an electric fan originally and just want it to work automatically with the original wiring and thermal fan switch. You need some 12ga "primary" stranded copper wire, an inline ato fuse holder, a 25 amp ato fuse, a standard 4 or 5 pin relay 25 amp or larger or a typical fan kit that includes a relay that can handle at least 25 amps, a 12ga (yellow) eyelet terminal that will fit over your alt B+ stud (probably 5/16?), 12ga butt splices, four or six inch black zip ties, good crimping or soldering skills, and some electrical tape though heat shrink would be nice. It will act like a one speed, 1450 cfm fan. Edited July 20, 2022 by MV8 Link to comment Share on other sites More sharing options...
ChuckM Posted July 20, 2022 Author Share Posted July 20, 2022 Steve, you must be a pro! Thanks very much the wiring diagram, my own installation does have a relay, a 30 amp fuse and a manual switch (I used the wiring and switch for the heater fan as an expedient). With everything wired I can turn the fan on low speed then high speed, but when I turn the ignition off the fan keeps running? It must be something simple so I’ll keep trying different things. Thanks again for your help! Link to comment Share on other sites More sharing options...
MV8 Posted July 20, 2022 Share Posted July 20, 2022 How is it wired exactly? I'm confused about what the benefit of the relay is if all 21 amps flow through the htr control, assuming htr low or high is connected to pins 30 and 86 (15a plus the relay coil), with the other speed direct to the fan motor (6a). The heater shares the same FS2 fuse with the original fuel pump wiring and all the instruments. This should be a 10 amp fuse (very weak htr blower by modern standards) so you must be applying power to pin 30 from somewhere else. I have electrical experience in a many fields but I'm no EE. Link to comment Share on other sites More sharing options...
ChuckM Posted July 20, 2022 Author Share Posted July 20, 2022 MV8, Auto electric is not my forte’. So are you thinking I don’t need the relay and I can just plug into heater power source? Link to comment Share on other sites More sharing options...
MV8 Posted July 20, 2022 Share Posted July 20, 2022 (edited) I'm saying if the fan or fan and relay has all power routed through the 10 amp htr fuse, it should blow if the fan is operated at all unless some other voltage source is jumpered on to the circuit that includes the fuel pump and instruments, which could also cause it not to shut off if that source is constant and not switched. However, if that were the case, the instruments and fuel pump would continue to run also. You can use the heater control as a control for fan speed with two relays if pin 30 is powered by another circuit such as the alternator B+ stud. I can draw a circuit like that if you'd like. Edited July 20, 2022 by MV8 Link to comment Share on other sites More sharing options...
MV8 Posted July 20, 2022 Share Posted July 20, 2022 This is fully manual hi and lo using the heater blower control and powered by the alternator directly, with no mods in the cowl. Link to comment Share on other sites More sharing options...
SevenAmerica Posted July 21, 2022 Share Posted July 21, 2022 but the original Lotus Seven had its fan in front of the radiator and that was good enough -- haha -- My '61 Seven has an electric fan (Spal puller) behind the radiator too :-) My 948cc just got too hot! (sorry, I only clicked this thread because I thought it was about a need for bushings) Cheers! 1 Link to comment Share on other sites More sharing options...
MV8 Posted July 21, 2022 Share Posted July 21, 2022 ATO 12ga fuse holders: https://www.ebay.com/itm/222701017687?hash=item33da03da57:g:RrwAAOSwax5Yucq~&amdata=enc%3AAQAHAAAA4HXq938zEWacFxxo%2BoXAro%2BVA92qXKpfmq%2BMHg568oPD808QBGZlpT%2FnLV8kKq%2BTj02JqWmoA7JWTYXZezWN8Y%2B1vROmudjCOayXoC2e%2BXCWZTX00vpOoH5u4TNFMOMBtKBwNGE2TvYLCz0hvGAOovTpsEyy1VQltgJYQyzDyighuLmw2T0k870DiB1%2BY1YthQ104cy1rFt2zFa05rxJUka0dbr9LzP8hYba%2BMQEqTLim5b9RQaRja019dAqhw3bbWDP9F%2B4OXk3euktOiZQbfWT6OxX83L9rPHM%2BpJU2zNI%7Ctkp%3ABk9SR4imsYvEYA Relays with standard sockets, wire, and spares for $11. (Ignore their instructions. Colors versus pin # are wrong): https://www.ebay.com/itm/193476931588?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D240677%26meid%3D401c0c74c78b44819aa64889a88fa2bc%26pid%3D101195%26rk%3D2%26rkt%3D12%26sd%3D181830593598%26itm%3D193476931588%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv9PairwiseWebMskuAspectsV202110NoVariantSeedKnnRecallV1BERT&_trksid=p2047675.c101195.m1851&amdata=cksum%3A193476931588401c0c74c78b44819aa64889a88fa2bc%7Cenc%3AAQAHAAABMEro4ql1SUJ1li87bKftud%252BHNR6f%252BZqZvMWaqvYIq1S%252FWkIBqj9FQDQRu6mAcNzuioXWUR932%252F68tDooavd6O6RvCCK3TeOHWkQHDWVcom10WbzComl5EbRzgV9CqOJMQUuOa5b%252FYT%252F%252Bhj2k145OKDcRDlZcKKZnUOytXBh5Dx3L05aXN6TjgNFcLL4bI0HIubDN7bnbShjZj9ZOJN7mmlH%252BOlDpDw8B%252FSGhZfVKnmZzh2KTv6NBv15S7rILihl08Wij1WPEZeVXuQK5Eq%252BhRzb0Rmlbzi7ae2YoaIu8%252FXUVPWrKHsMEVdgGe0fHpw2OtSLIdN4OVgQGyNQjCC8tjRRwtin4HIqMTRDOhZlJaFJ81aEcM7dlEPP0sV5alacEYGP4uYn%252F4%252FfOjrBOPXefmuc%253D%7Campid%3APL_CLK%7Cclp%3A2047675&epid=11051074327 Heat shrink assortment. Just need a smoking lighter's heat to shrink it: https://www.ebay.com/itm/384790486322?epid=27053026603&hash=item59974cdd32:g:kTYAAOSwTcNiN5SG&amdata=enc%3AAQAHAAAA4LWZf6or4A3ErQXDZXoFvUxEBUV%2FA9us3vMqKtvclrScNrlGL5dhr2jrFVQyooWrnmp3q0PpPWYeAG0Ci0SAVYycZ%2F%2Bt5mqByIJpJwvaAFlscnvnLtZwkjPuGSvdXF1NqlDUbGCZGf4Vn9fxy6T6fm0d9PCDZH4KTIQo821GuE%2BAeMXoh8C%2Fr92rFoSiPQjEFEWVkS7VVV3fKZ2k%2BDG8a25VOHyZ7scxY1K3V9r5mxa2QbHu1AjJjs6lFnaUaQLmeCVRe8rnR4aQXJM5Xp82KQBRq6PWiY3I5RcAMB9L2Bdb%7Ctkp%3ABk9SR7CZwZDEYA Link to comment Share on other sites More sharing options...
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