Oil/ Water twin temp. measurement

[Pierre Gillet]

Just completed the installation on my 1.6K of a switch on dash and an oil temp. gauge on oil filter housing. The figure I read for water temperature is now about 10°C higher than it was before. I figure that it is because of the additional electric resistance of the switch (standard Caterham) that seems to amount at about 1 Ohm.

Anyone with a similar experience of this phenomena question.gif

 

Pierre

[Dominic Berry]

Pierre

 

I want to add an oil temp sensor to my K-series. Which sensor did you use and where did you source it from? Where and how does it attach?

 

Dominic

 

PS I'm not an electronics expert but 1 ohm sounds quite high for a switch. The resistance should be negligable. Was that resistance measured across the switch without anything attached? If it is I'd try another one.

[Pierre Gillet]

Yes Dominic,

that's what I thought too. I have to check my controller. Also I made the measurement on another (cheap)switch not installed on the car because it was easier to do so. But I have to try accross the Caterham switch procured from caterham and which is already installed.

The temperature sender is a Rover Water temp( max 120°C). I taped the blind hole ( kind of of cylinder)that is pointing toward the rear at the base of the oil filter housing close to the filter itself. The sender is neither in the oil flow, nor in contact with the oil ( because I was concerned about a possible leak and did not dare drilling the blind hole ) really measuring the temperature of the filter housing, but I figure it is OK given that what I want to know is really when the oil is really hot before flooring the throttle.

I may improve the installation though later by drilling the blind hole but then I have to make sure that it is going to be tight. I figure a problem with the thread of the sender which is 100 (?) or 125 ( not so easy to find, as it is normally 150 for M10 screws. In fact I re-taped the sender to 150 with the tap I had since I was not concerned by the tightness).

 

Pierre

[Pierre Gillet]

Now it does work. Took me time. I had problem 'cos I had not identify the correct wire connecting on the gauge from the water temp sender. I used the black one instead of the green one...

Now that it works , I must use it!!!What is the minimum temperature of the oil before I can floor the throttle? My engine is a 1.6K and I am using 5W50 oil.

 

Pierre

[Dave H]

Pierre,

I don't know what the temperature should be, but, if you warm the oil up - that is, wait until the oil pressure at idle is half what it is when you first start the car, then what your gauge says is the working temp.

[Pierre Gillet]

 

Thanks Dave. It makes sense. I 'll test the method tomorrow since the weather is supposed to improve...

regards,

 

 

Pierre

[Peter Carmichael]

5W50 is an enormous range for a multigrade. Received wisdom suggests that using a smaller range means you have more oil and less in the way of viscosity modifying additives - the oil lasts longer without breaking down and more of the fluid in the bearings is film-forming oil.

 

Of course, such ground rules may have gone out of the window with synthetics.

[Pierre Gillet]

OK Peter now the question is how can we check the lifetime of the oil. Having no unexpensive way to do so, I can only rely on the recommendation of caterham which is to replace oil every 5 000 km. I replace the oil filter at the same time.

The oil that I am using is under the generic name of CARREFOUR, a chain of hypermarkets here. It costs 159 FF for 5 liters and meets all the specs of Mobil 1 (although Mobil 1 is supposed to exceed them) and is SAE tested. I suppose that it is made by Mobil...since no other oil fabricators here can make an oil with such a wide spec range.. my engine, a modest 1.6 K 115 BHP has done 28 000 km on roads at high RPMs though, and is still alive. biggrin.gif