Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: Europa73 on Tuesday,June 20, 2017, 04:33:39 PM
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Hi all,
Just took the TCS out for the first time - and - my first time in a moving Europa - WOW
But - its running hot - needle settling around the marker to the right of 90.
During the restoration I did take off the swirl pot for painting.
The hose coming out of the engine (by the thermostat) is very hot - but - the hoses at the radiator are nowhere near as hot.
Could this mean the rad needs bleeding?
Any advice would be greatly appreciated.
Thanks,
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If in doubt, I would burp the radiator (again). It doesn't seem like your thermostat is bad but you could when it opens (you can use a thermometer and a pot of water on your stove). I would also note that the mark past the 90° mark (see the graphic I've attached) is not THAT hot. I have a fan controller and a radiator fan switch. I tried the radiator fan switch for a change it it got as hot as you describe. I thought it wasn't working but the fan kicked in a short while later and cooled it down to about 90°. I decided to use the controller but the fan switch can be wired up easily for backup. I only mention this in case that is the way your fan switch works. I don't remember it behaving that way way back when the car was new. There are also products like Red Line's Water Wetter that helps the water stay in contact with the radiator and helps reduce your temps.
I'm assuming your ignition timing and fuel mixture are reasonably close (not too advanced or lean), that you have enough coolant, and that your water pump is working (proper belt turning the pump, the pump isn't showing signs of distress like leaking water).
Everybody complains about the cooling system in a Europa. I certainly wouldn't say it's over designed but I lived in New Orleans and when it was new, I drove through the Nevada desert in the afternoon (trust me, you don't want to try that) and I don't remember having any cooling issues. I would say the stock system is adequate. You can help yourself with an aluminum radiator and a high CFM fan (I did) if you feel you need it.
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HI:I had an issue with my S2.The rad has a baffle in it about 1/2 way down that forces the water(coolant) to circulate properly.Mine had come loose and coolant was in effect bypassing part of the rad.
I was worried that I had a bad head gasket !!
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Hi there,
As BDA shows, the recommendations from Lotus themselves do show quite a variation and from what I recall the stromberg engine versions did run at slightly higher temperatures so I wouldn't get too wound up unless the engine was clearly boiling and blowing water out.
However.... I've usually had to bleed the radiator at the front to remove some trapped air so if you've not done so, that's the first job. Also check the heater is working, not so much to keep your toes warm but to ensure that water does circulate around the pipes and there's no air lock. I usually find that slowly filling the system with the engine running takes care of that aspect, but it's worth checking because if by some chance you had a lock on initial filling then you might find you're a bit down on total coolant.
If the coolant volumes are about right, there's no air locks and you're still concerned then I would check the gauge/sender combination. In my notes I have a page where someone measured the voltages/resistances of the Europa gauge/senders but unfortunately I've just checked and the original is no longer there. So with cut'n'paste here's the data for the temperature gauge.
Temperature gauge
Temperature Voltage Current Sender Resistance Sender Voltage
(C/F) (volts) (ma) (Ohms) (volts)
70/158 3.05 51.3 135.5 6.95
90/194 4.31 72.2 78.8 5.69
100/212 5.15 85.7 56.6 4.85
130/266 6.55 107.8 32.0 3.45
This data is for the S2 but..... the S2 & TC have similar numerical part numbers and so it might be useful as a starting point. When I had cooling problems (before finding this chart) I simply took out the sender, wired it up with extension leads and popped it in a kettle of water. When it boiled, I checked the gauge reading to see where 100C came, which was pretty much on the mark to the right of the 90deg. figure. At least that way you'll be certain when the engine is approaching boiling although in my experience it's clearly unhappy and throwing water out when something is wrong.
Brian
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Many thanks for all the grate advice.
Much appreciated!
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I don't know how long your TCS was sitting but make sure that your coolant pipes and radiator are free of rust and crud. When I started up my S2 for the first time after sitting for several years, I immediately plugged up my radiator with the rust that had settled in the low points of my coolant pipes. I would back flush the radiator and run a garden hose through the pipes with the hoses disconnected from the radiator. You will at least know that your problem is not a flow issue.
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thanks - will do
Sounds like a fun job :-(
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Hi all,
i hope this is not going to be bad news.
I bled the rad - flushed the pipes and the car is still running hot.
needle resting on the 1 of the 130 on the temperature gauge.
I have no leaking from the water pump - and the heater works well.
I did notice that the rad is very slow to heat up and the top hose next the the thermostat housing is way hotter than the hose at the front of the engine.
Is there a way to test my water pump is operating correctly
Second I will test the thermostat - any advise on what thermostat and gasket it uses in the TCS
Many thanks,
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just repeatedly tested the thermostat - and it opens wide up in boiling water.
next test the sender.
any thoughts anyone?
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IIRC, the thermostat is marked for when it opens. I would check that it opened at the right temp, but since it opens by 100°C, that isn't the cause of your overheating. If it's not opening soon enough, it may not be helping you as much as it should but I think the failure mode is not to open rather than at the wrong temp.
Testing the sender is a good idea.
I'm sure someone out there has a better idea, but you could test your water pump by taking out the thermostat and pulling the top radiator hose. When the motor is running, it should pump water out of the radiator (somebody please correct me if I'm wrong - but either way, you'll see movement somewhere quickly if it works!).
Are the rest of your gauges behaving properly. If not, I think your voltage stabilizer could be causing you trouble. Here's a link that might be helpful: http://www.minimania.com/Smiths_Voltage_Stabilizers
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What is the temperature rating of there thermostat? Use a cooking thermometer and check and see when it actually opens.
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I have no leaking from the water pump - and the heater works well.
I'd take that as a positive, if the heater is working then I'd be 99% convinced the water pump was doing it's job as well. The feed/returns for the heater are only 1/2" pipes and so I'd be very surprised if that would operate by thermosyphon alone, I think given the layout it will need some pressure from the pump.
I did notice that the rad is very slow to heat up and the top hose next the the thermostat housing is way hotter than the hose at the front of the engine.
Is there a way to test my water pump is operating correctly
Now I haven't tested mine, but I'd expect the top hose to be significantly hotter than the one into the front cover plate, that should be the return from the radiator. I would expect to feel a notable difference between the top and bottom hoses of the radiator as well.
As for testing the pump I think that's a bit more complex. I can think of checking the drive belt is good and turning the pump with no slippage, but after that I'm not sure of any definitive tests you could do easily. It's a simple design and if it's not leaking then the only way it can't work is if the impeller has broken up (noisy, wouldn't turn) or is slipping on the shaft. That actually happened on mine, but it was my first replacement pump and with hindsight it did press onto the shaft with little pressure; we put it down to not being machined correctly because the second one was much tighter and is still there today. I can't imagine that's the problem with yours.
Perhaps with the thermostat removed and the radiator cap off the header tank you might see some level movement if you flicked the engine from tickover to say 3,000rpm rapidly ? I'm clutching at straws really.
My thoughts are with BDA, check the instruments. I'd put a meter between the regulator and gauge to see if it's getting 10v or 12v. Incidentally, is the fuel gauge about right or is that also reading higher than expected ? (same feed)
As for the sender, it's easy to see if one has failed completely because it will have virtually zero resistance & go directly to earth/full scale deflection on the gauge. One that's partially failed is harder to spot without checking the resistance vs temperature. There's also a chance you have the wrong sender for the gauge, I think they do come in different resistances ?
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I would buy and use an infrared temperature gun. You can use it to measure the temperatures throughout the cooling system. I made a variable voltage voltage stabilizer so that I could calibrate the temperature gauge. It read about 15 degrees high with the original voltage stabilizer.
The voltage stabilzer voltage directly affects the temperature gauge reading so it may be your problem if your temperature gun shows that the temperatures are actually normal.
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Temperature gun -thats a great idea!
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If you use an IR thermometer gun, make sure that you are using it correctly to get accurate and consistent readings. I failed to read the gun instructions and kept getting inconsistent and wrong temperature readings. Couldn't figure out the reason and blamed the gun instead of the user. The link below has a good explanation of why working distance is critical.
http://en-us.fluke.com/community/fluke-news-plus/temperature/how-to-get-great-results-with-an-infrared-thermometer.html
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You can get some feed back by feeling the flow and return pipes through the hole under the armrest. You should see the needle on temp gauge drop a little as the thermostat opens.
Also - is the spare wheel blocking the front grille??
Steve_Lindford
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As for the sender, it's easy to see if one has failed completely because it will have virtually zero resistance & go directly to earth/full scale deflection on the gauge. One that's partially failed is harder to spot without checking the resistance vs temperature. There's also a chance you have the wrong sender for the gauge, I think they do come in different resistances ?
I think my temperature sender has failed. It has a far lower resistance that two others I have tested. 383 against 1180 on my meter.
The engine warms up super quickly and then goes to 130'C just as the water is passing through the radiator. New rad, new thermostat, completely flushed through coolant system with antifreeze, and no hissing when I undo the new 10 PSI pressure cap on the reservoir. New sender on order from SJ Sportscars.
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New temperature sender fitted from SJSportscars.
Running very hot problem now cured. As suspected, the sender was giving a false reading, and the new sensor has the car running at 90'C, so no major dramas or expenditure.
At an air temperature of 10'C the resistance of the old sensor was 38.3 ohms, whereas the new sensor had a reading of around 117.0, which seems to tie up with the figures posted by Europa TC earlier in this thread. At 38.3 ohms, I reckon the temperature reading of the broken sensor would be about 125'C, which it was reading, hence my concern.
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:trophy:
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I know from being in the industrial heating systems business (kiln building) that measuring temperature accurately can be quite difficult. Anything and everything from the sensor to the sensing circumstance (where, how, etc.) to the readout, and any electronics in between can and will affect your measurement. The more measurements the merrier I think, as you start to get a consensus. But in many many circumstances, there's no way to get additional measurements.
So just beware: you can't trust anything by itself. And there is no reason that something that reads out digitally is any better than something that reads in an analog fashion.
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I know from being in the industrial heating systems business (kiln building) that measuring temperature accurately can be quite difficult.
Measuring temperature (electrically) accurately............
Surely measuring anything with a mechanical sensor (mercury or the wax probe thingy with the long capillary tube surrounded with coiled wire) is more accurate, but less convenient.
I knew something was amiss as the gauge was recording 130'C but the expansion tank was cold, and the filler cap was not pressurised. At standard pressure, pure water boils at 100'C, if pressurised that can rise to say 120'C, but there was no pressure, it came up to temp far too quickly, and the top rad hose had only started getting hot = the thermostat had only just opened to allow free coolant circulation. I don't know how antifreeze affects the boiling point of water. I know it lowers the freezing point, that is its purpose, but I don't know how it affects the boiling point.
I worked out that the pump sucks water from the radiator, pressurising everything north or upstream of the pump, so I knew it was not at 130'C, it just did not add up.
Anyway, the new sensor seems to be performing as expected.
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That's great that you've got it handled.
And you've got me thinking that I should try to do better. My gauge reads as below (orange line) if the ambient temperature is below something like 85 degrees F, and I've come to accept that I don't really know what the temperature is, but it's under control. It creeps a bit higher at higher ambient temperatures, but with the fan on it still doesn't peg at 130. So I've been satisfied. But you've got me thinking that I'd be glad to have a little more accuracy here. Even if my gauge and sensor are pretty accurate though, I wonder what that temperature is that's showing on the gauge? I don't know how to read that thing. LOL!
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I've attached a picture that gives an indication of how to read it. The hash marks are not halfway between 50 and 90 or 90 and 140 as I tend to think about them but it seems clear that your water temp is over 100°C which may not be terrible (I assume you're not boiling water out of your system) but when my car was new, the needle was always just before the 90° mark which is what I aim for (actually, my car runs closer to 75°C but I have a different engine).
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Thanks. I think you posted that earlier in the thread. It looks like it should be helpful, but given my 130 maximum, I'm still uncertain about what is supposedly my temperature.
Some day I'll use a thermocouple which should be quite accurate and thread it in past a hose coupling and get a real idea of the temperature. For now I think my temperature is "ok".
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He he… I went back and saw where I posted that graphic before. That’s happened twice recently!
Based on my experience, I would say your car is running warmer than it should but unless you’re boiling over water, you are ok but you should be running cooler. I would try to find why it’s running so warm.
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I think it was generally accepted that the Stromberg cars ran hotter than Weber/Dellorto cars, it was mentioned lots of times in my Club Lotus days.
Miles Wilkins also makes a passing reference in his book on the TC, saying that they run 5C hotter than Weber engines, 95C being normal. He put that down to several things, the leaner mixture, port shape and, in the Elans, the smaller radiators introduced at the same time. The radiators are the same on Europas so that reason is out, but even so I wouldn't be surprised to see them a touch warmer.
Brian