Lotus Elan and Lotus Elan Plus 2 Forums

I have a 1967 Elan series 3 DHC which I recently bought and drove back from Sweden to Paris (there is a photo report elsewhere on the forum).
During the entire journey, the temperature gage wasn't working, but the car didn't to my knowledge overheat and the journey was fine. The oil pressure half did work and the reading was correct throughout.
On my return, I bought a replacement oil/temperature gage from a reputable specialist in the UK, who said the one they were sending me was for a series 4 car, but that it didn't matter as it was basically the same.
I have had this fitted, but have since noticed two rather worrying things.

1/The oil pressure gage remains on maximum (60psi) for about ten minutes after the car been started before gradually beginning to reduce.

2/If I sit in traffic for more than ten minutes once the engine has warmed up, the temperature gage also goes round to maximum (110?)!

So my questions are as follows: Could this due to the wrong temp/oil gage being fitted, or has the mechanic who installed it
failed to properly regulate the sensors? The Elan doesn't seem to running any differently than it did all across Europe, so I hope I am not also looking at serious engine problems. Thanks for any comments. Philip

It is normal for the oil pressure to be high on start up until the oil warms up. Then it should back down to 20 or so lbs depending on the type of pump installed. The Elan is a low pressure high volume motor.

Assuming the temp gauge is correct and the only way to determine that is to pull the bulb out of the motor, then stick it in a known temp water and check it. Or you can do as I do, I use a laser temp thing, cheap these days a under $50. Just take off the cap (carefully) and check the temp of the coolant with the laser. Or just point it at the radiator, it should give you some idea.

but if it is correct then your car is running hot. You may want to install a Kenlowe electric fan on the front of rhe radiator and get rid of the fan blades on the water pump. (If that is what you have). You can also get a lower temp thermostat. If the cooling system is not maintaining the temp at the thermostat temperature then you have some sort of failure in your cooking system. Maybe the radiator needs to be refurbished, cleaned or re cored.

110 Celsius is 230 Fahrenheit which is too hot. First check the gauge, then look for why you are not getting the cooling you should be getting.

If the car stays cool when driving but gets hot when stationary.
That is a usually cooling fan problem.
However as Tony suggested you need to check that the gauge is reading correctly.
I have had experiences of gauges reading hotter than it really is.
Clive

Rereading my post, I got thinking perhaps a brief description of how a cooling system works is in order.

You have a radiator which cools the coolant. You have a thermostat which open and closes at a specific tempearture.

When you start the car, the coolant temp rises because the motor is creating heat. The thermostat is closed not allowing coolant to pass through the radiator. This allows the motor to heat up faster which is better to raise the temperature of the oil to allow better lubrication of the motor. As the temp of the coolant reaches the temp of the thermostat, the thermostat opens allowing coolant to flow through the radiator cooling it. This constant opening and closing of the thermostat, allowing the flow of coolant to the radiator and not allowing flow to the radiator is what is supposed to keep the motor at the correct temp.

So, if when the thermostat is open, you are getting max cooling and this is not cooling the motor down to whatever temp your thermostat was manufactured for, then there is something wrong with the cooling.

If you are sitting at a light, no air is moving into the opening in the front of the car, thus they put fans on cars to create air flow through the radiator to cool the coolant when you sitting at lights. The fan blades on the water pump of an Elan are just not up to the job in most cases. That is why you should put on an electric fan. If you have a fan, then it is either not moving enough air through the radiator, or your radiator is not doing the job it should be doing.

Very simple. I agree with the above post, but I have seen it where the volume of air moving through a bad radiator is fine when you are driving but not when you are pushing air through it with a fan. But saying that, I also think this points to airflow. Look at the fan if you have one or add one if you do not. You will cook the motor if the gauge is right you dont take care of this.

If it's going to 110 only when in traffic/not moving, but is fine when moving I'd think cooling fan too.

Is your cooling fan kicking in at all? Have you checked by just leaving the car running while stationary?

If it's going to 110 in all conditions....

I had a panic attack one day a few miles after leaving home when the temperature guage soared up to 120

Limped home trying to ensure teh car didn't blow up.

Had a good look and it certainly did not seem to be overheating.

So, out with a thermometer (probe type) and strapped under the top Rad pipe between it and the thermostat housing in the water stream.

All temperatures fine. Fan even came in exactly when it was supposed to.

The sender had failed. New sender in, all perfect.

So.....see if you can check what the actual water temperature is. If ok, then check if your sender is working and the CORRECT one for your guage.

On oil pressure.

Cetrainly here at the moment (when it's sub zero most mornings) my guage sits up towards 60 lbs for a minute or two.

At idle, when hot, I have around 30lbs, and around 40 when moving (mid revs and up).

(Pre rebuild, idle was around 18 - 20 and moving 38 ish).

When I FIRST got my +2 it was 60 a lot of the time, but I found that a previous owner had a high pressure pump in....

Best of luck.

And if Johnny Sexton IS joining Racing Metro....please take good care of him for us!!

Peter

peterako wrote: check if your sender is working and the CORRECT one for your guage.r

I believe the car is a S3 so unless it has been modified it will have capillary tube type gauge (non electric) and does not have a sender as such.

Thanks for the clairfication Brian.

My ignorance.

Peter

Lots of discussion about Capillary temperature gauge in my topic:
lotus-elan-f19/getting-ogu-roadworthy-again-t26101.html

Your best bet is to check it by carefully unscrewing the cap nut of the sensor bulb & taking it out & plunging it into boiling water to see if the dashboard gauge reads 100 deg C. Bung a rag or a cork or a 3/8 plumbing cap-nut in/on the hole to avoid losing coolant from the engine.

Presumably since you only recently fitted it, you know how to get it out and you won't twist & break the thin capillary tube.

tvacc wrote:This constant opening and closing of the thermostat, allowing the flow of coolant to the radiator and not allowing flow to the radiator is what is supposed to keep the motor at the correct temp.

I believe the thermostat opens as described but isn't constantly opening and closing like an on-off switch but rather modulates as a valve, i.e. varying the amount it is open to control the flow of coolant through the radiator, the amount of opening controlled by the temperature of the coolant flowing through it. In other words if the engine coolant is running hot the t-stat will open fully but if it cools down the t-stat will start to close until the temperature stabilises at the specified rating.

What does the temp gauge read during normal driving?
What temperature thermostat do you have?
Does it work?
Do you have a mechanical fan?
Is the coolant topped-up?

In a traffic jam, in the heat of summer, you might get to 100 - 105oC - Neither you or the car would be happy!

I think you would expect the condition you describe, Philip, if you have a fan on the water pump, but not if you have a correctly working electric fan.
Regards
Richard

I repaired my temp gauge over the weekend.

When I was done, I tested it. You can see me testing it in my post:

electrical-instruments-f38/temperature-gauge-rebuild-completed-t27244.html

I think you should test yours to make sure. Just boil some water, put the bulb into the water and it should read 100 Degress Celcius.

Thank you so much for all your very kind replies.
I forgot to mention that my Elan was in fact fitted with an all-new aluminium radiator prior to purchase, which makes me think that
it shouldn't really overheat.

I will take her out for a drive when I can, but I am still waiting for the French police to issue me with French plates as I no longer have the right
to drive in France with the old Swedish number plates. I have an appointment on Friday, after which I am told I shall have to wait another three weeks before being issued with a new registration number (b****y French bureaucracy!!).
So just as soon as all of this is sorted out I will go out and test the temperature and oil pressure levels and report back.
Thanks again. Philip

While you are waiting for the plates why not fill in time by testing the accuracy of the gauge in the way others have suggested?
If it hasn't got an electric fan and it reaches 110 with an already hot engine idling but the car literally standing still for ten minutes (ten minutes is a long time to stand quite still) I wouldn't be surprised or too worried.

Hi everyone,

Well as I am still waiting for the French prefecture to issue me with a definitive registration number and despite being advised not to drive my Elan until I received it (the date is 5th March) I decided to brave the elements this morning and to take the car out for a spin around Paris for the first time since October and share my findings:
It was a clear and cold morning, with outside temperature around 5?C.

The car is not running as smoothly as I would like and it tends to backfire quite a bit and is sometimes a bit sluggish, but at speed runs okay and even though she coughs a bit, she accelerates well. Maybe the fact she has been sitting for a long time without being driven has put the carbs out, or maybe the engine just needs a good tune up.

Concerning the temperature, after the engine had warmed up it rose to between 70 and 90?, but did not exceed this, even when waiting at traffic lights. This may also have been due to the fact that there was nearly no traffic on the roads and it was a cold morning. As I mentioned, the car is fitted with a new aluminum radiator, but has no Kenlowe fan.

Concerning the oil pressure, as I mentioned earlier the pressure reads maximum 60psi on start up but this slowly recedes as the engine warms up. Then sitting at idle the oil pressure reads between 25 and 30psi. But once the engine is revved and the speed exceeds 40kph the needle goes back to maximum 60psi where it stays until the next time the car stops. I'm not sure whether this is normal...so can anyone advise?

The fact the temp gauge didn't go over 90? came as a nice surprise, (as this certainly wasn't the case last time) although the constant maximum oil pressure reading while the car is moving is something I don't remember in the past, especially before the removal of the former oil pressure gauge.

As for testing the temp gauge at home as some of you have very kindly suggested, I would have liked to have done this, but as it is now fitted it would be complicated to remove.

However, once I am issued with the new number plates I will take her out for a longer run (probably on the motorway) in what will hopefully be warmer conditions to see if the temp reading remains the same as today. I'll keep you posted.
In the meantime, thanks again for your very kind help and advice. Philip