Lotus Elan and Lotus Elan Plus 2 Forums

Hi guys

Wonder if you can offer any help. I took my 72 sprint out today for run, as she?d not been used for a while. After 10 mins I noticed that the water temp was hitting 100 degrees. I stopped and realised the fan hadn?t kicked in.

I then couldn?t start her at all, checked the plugs which seemed ok, but the engine block felt really hotter than usual. Turning over fine, but no firing. Battery went after a while, so I got a jump & eventually got her started after much trying.

Drove home and parked up. Still no fan, rad steaming, engine super hot, also noticed that the lights wouldn?t pop up, so vacuum issue somewhere.

So, does this sound like water pump? Thermostat? Electrics?

I?m just hoping I?ve not damaged anything by running without a pump if that?s what it is.

Any advice welcome! Thanks

Have you lost water ?

If your fan is electric then it sounds like an electrical fault. No fan will result in eventual overheating but 10 mins is quite a short time unless your somewhere hot , it?s freezing here in Southampton , the lack of vacuum is probably just another minor problem and unrelated.

If the water pump had failed it would be leaking or squeeling

Steve

I may have lost a little water, but was hard to tell as the cardboard on the garage floor was a complete state. There?s always a bit of oil coming from somewhere... but it?s been like that ever since I bought her 15 odd years ago!

It?s the original electric fan I think, certainly looks 45 years old. The stat is cable-tied to the top of the rad, and not in good shape either, contacts were looking pretty corroded so will have a clean up tomorrow hopefully. Yes was driving 15 mins tops and it was 5 degrees. I was pretty surprised to see the water temp gauge so high after such a short run...

Thanks for the comments. Any other checks I can make?

Sounds like thermostat not opening, if it stays closed the water at the rad. will stay too cool to switch the fan. [ assuming it's an electric fan ] Pull the stat and try it in hot water.

Cheers Aussie, I will try that ...

... so it?s not the thermostat, judging from this pic attached, looks pretty open... was rated to 88 degrees and opened nicely.

Is silicon ok to refit the stat housing, or does it need a gasket? The remains of something fibrous disintegrated when I took the housing off, so I cleaned it up.

You should be OK with a silicone sealant.

It is worth testing the fan sensor the same way, checking that the contacts close with a multimeter (or bulb and battery). And you can also try taking all the connectors off the fan and connecting the battery across it to see if that is working. Be careful!

With the ignition on just join the two wires on the otter switch and the fan should run [ make sure the fan is running in the right direction ] Is the radiator getting hot? If not then no water circulation, maybe a collapsed hose inside?

Hey - funnily enough I took out the otter and touched the wires together... I got a spark, but the fan didn't run, so that might be it then?

I'll try Quart Meg's suggestions too.

Cheers guys

Will

Will5000 wrote:Hey - funnily enough I took out the otter and touched the wires together... I got a spark, but the fan didn't run, so that might be it then?

I'll try Quart Meg's suggestions too.

Cheers guys

Will

does the fan turn freely when pushed by hand (contact off)? if not you may want to take it out and try help it with lubricant, or even to take it apart for a good inspection...

yes - fan turns very smoothly... all a bit rusty mind!

Remember the otter switch only brings in the fan relay so it could be the relay or wiring to it [ on a +2 the relay is on the n/s in front of the rad..] put a meter on each wire to the fan with the other meter lead to earth, you should have 12v on one of them.

Cheers... sadly I won?t get another chance to check until Saturday, but I?ll let you know how I get on.

Thanks to all for the advice!

Will

So - by means of an update... today I got the chance to have a good look. The otter was at fault.
Stuck it in a pan of boiling water for 5 mins and no current flowing. Also discovered the t-joint at the base of the chassis with vacuum hoses was split through, which explains the headlights. Got a new otter, so fitted it and will test when I?ve wired it in and replaced the t-joint!

Thanks again for all help.