Overheating, coolant leak warning

[Michael]

Overheating/coolant leak…<br><br>Well, of course it happened to me too. And, inconveniently, it occurred during our tour-rally with a group of cars somewhere in the middle of France last week. <br>Although solving the problem we missed a full day of the trip we were very lucky it did not happen in the middle of nowhere but just in a town where immediate professional help was available.<br><br>Here is what happened, a warning to all of you?<br>Really without any previous signals (no previous signs sees on the temp gauge), just after an hour of really calm driving, we were waiting in line for a gas station with the motor running when smoke appeared from under the bonnet and there was the smell of coolant.  <br>I opened the bonnet and there was a lot of steam coming from the back of the engine and the backside of the engine bay was quite wet. We stopped the engine and checked the coolant level only to find out that it looked like there was noting left in it…...<br><br>A helpful mechanic was at hand and he discovered that the ‘heater valve’ was broken. This seemed the result of rust on the part where the rubber water hose is fitted to the metal piece of the valve. As emergency reparation they soldered and glued the torn/broken metal part, refilled the engine with about 6 litres of new coolant. This way we were able to join the group and continue the tour carefully watching the temp gauge.<br><br>The next days I still smelt coolant now and then and the engine appeared to heat up much too quick when driving slowly or standing still. Apart of that I had to refill coolant a couple of times. I checked it again and found out that the soldered part was still leaking coolant a little. <br>Because the radiator fan functioned OK and the engine did not overheat I figured it could not be the thermostat and we were able to carefully drive the car but I did not like the idea of travelling over 1.000 km back to Holland this way…<br><br>So this is what I did. I ordered a new heater valve by phone and my Lotus dealer instantly mailed one to me in France. It arrived within two days.<br>It puzzled me that when I took the broken valve out everything stayed dry. No coolant ran out of the coolant system although the hose was now totally open. In the coolant tank the level was still OK.<br>Someone suggested there might be a bubble of air in the system and that this also might be the cause of the very fast warming up of the engine.<br>Well, to cut a long story short, this was indeed the problem. I had to refill coolant, and after carefully letting the air out I had to add almost 5 litres!<br><br>This seems to me like the tricky part of it. <br>The fact that I had to add 5 litres proves that the loss of coolant was quite impressive. Apparently I lost it during driving because the never was (much) leaking visible after parking the car. All the time the coolant level in the tank appeared to be all right and according to the movement of the temperature gauge the engine did warm up very fast but only when driving at a walking pace(!) after which the radiator fan cooled it from ¾ to 1/2 level on the gauge. <br>So I am glad I did not get into more serious problems on the way back to Holland after finding this out and solving this problem.<br><br>Everything now seems to work fine. I am a still little uncertain about the thermostat but the water pump runs, the radiator fan functions like it has to and on the way back home we had no problems.<br><br>Well, it’s become a long story but since I am not a mechanic and have no knowledge about the technical part of a car maybe this will help other Elanists like me to get into the same kind of problem.<br><br>I suggest you take out your heater valve to check it? It is only a 5 minute job and maybe you can prevent the problems I’ve had.<br><br>Michael  <br>

[Michael]

@ Chris<br>Good pics and more on this you can find under this link:  <br>http://www.lotuselancentral.com/commonparts.htm#heater<br><br>I'll post my own pics later on (lack of webspace right now).<br><br><br>P.S. holliday fun was not really dampened. Only made a litte les mileage then we planned but will make up for that later on this year  ;)

[HenriElan]

Dear Michiel,<br><br>Your story makes sense to check over the 'heat valve', but honest I have no idea where this part is to be find on the engine or do you mean the 'thermostat' as we call it in Dutch?<br><br>Henri

[Michael]

@ Henri<br><br>No it's not the 'Thermostaat'.<br>Just follow this link: http://www.lotuselancentral.com/commonparts.htm#heater and you can see in clear pics the part involved.<br><br>

[Dimitris_GR]

Michael,<br>please be careful with this, because there is a (small in your case) possibility that this sad story of yours may caused a sadder one. A head gasket problem.<br>If when you "push" it a bit, it continues to consume water, and if you notice a brown surface on your water tank, then be prepared for a head gasket work in the future.

[clemo]

if you feel it is going down the head gasket route buy a " block tester" this little gadget tests for hydrocarbons in the water header tank..<br>it costs about £25 .<br>i have one . it is a great little tool..<br><br>

[Michael]

@ Dimitris & Clemo<br><br>THNX for your suggestions guys. I'll look into that!

[Doug]

[quote author=clemof1 link=board=techgen;num=1089015798;start=0#7 date=07/29/04 at 03:03:34]<br>i have one . it is a great little tool..[/quote]<br> [smiley=smileysex5.gif]   ::)

[Dave M]

After starting to put things back in the car this weekend, I took a look at my heater valve. Not only was the flap inside questionable (I don't know how coolant got through when it was open), you can see that it was pretty much a mess.

Don't know if it caused any loss of coolant (no traces on the outside of the hose), but I recommend having a look at this next time anyone is poking around their engine bay on a weekend.

[Nige]

Block tester Clemo refers to available here: http://www.frost.co.uk/item_Detail.asp?productID=8682

As he said, a useful little tool!

[Candles]

You could just replace it with a straight bit of plastic pipe. It only shuts when the heater control is FULLY cold, so what's the point in it? A weakpoint in the system I reckon that deserves to be eliminated

[F1 LOTUS]

I understand from my Lotus Guy (Harry) this is quite a common occurance for these to rot and leak? I think it is a Jaguar part?