Water pump gone?

[Roger Fairclough]

if you loose all your coolant with the standard temp sensor and gauge, you wont know about it as the gauge wont go up!

Oh yes you will. Air will transmit heat just as easily as water in a closed environment such as a water passage.

I have a 16" Kenlowe fan fitted in front of the rad. The standard fan has been junked, along with it's shroud. The fan is switched via a thermo couple screwed into the head outlet elbow. This TC opens at 100deg.C and closes at 95deg. C. In normal driving, even on hot days, the fan does not come on. The gauge stays just below half way. Only on steep climbs "off-road" or ditto deep mud will the fan operate. I have fitted a manual switch for emergencies i.e. the TC fails or if I want to drop the temp. before wading. This latter is really unnecessary, as wading will inevitably partially submerge the rad. and that will cool the system far more than a fan!

Roger

 

[Ben]

youve said that before Roger but im not convinced.

maybe i should test your theory and film it.

get the engine up to temp, and disconnect the bottom hose from the rad. then, as my digital temp gauge rises rapidly, see if the original gauge goes up or down.

obviously i would turn the engine off before it got too hot.

maybe i could test it at Lincomb!

 

[Crushers]

disagree completely ...
but if you believe it then that is fine with me,
poor advice

Oh yes you will. Air will transmit heat just as easily as water in a closed environment such as a water passage.
Roger

 

[Ben]

Wayne, im confused. is it me or Roger you disagree with?

 

[Roger Fairclough]

If you sit in front of a heat source, you will be warmed because the heat is travelling through the air from the source to you.

It's the same principal.

Heat will travel through the material of a substance if there is a difference in temperature.

This is conduction.

Roger

 

[Crushers]

Ben,
read the quote and you will see i agree with you and disagree with Roger.

Roger,
easy test.
take a old thermostat, insert in hot water and watch the reaction.
not take the same thermostat and insert into a tube, blow hot air same temp (214 F) onto it.
observe the outcome and report back.

 

[Roger Fairclough]

A thermostat works on temperature. It doesn't matter what the transmitting material is. If you refer back to my original comment, you will note that I referred to a closed environment, such as a water passage. Air is a bad conductor. Water is far better, but that is due to it's mass as opposed to a gas. Within the confines of a water passage, the temperature can rise quickly, as the heat is confined within it.

If you place your thermostat into boiling water, it will open. If you place it within a container of air heated to 100 deg. C, it will still open.

It is not the water that opens it.

It is the temperature of the environment that the thermostat is in.

Ben.

Your transmitter is bolted to a fitting on the cam cover. Your meter is reading the temperature of the bolt, which is heated by the cylinder head, which is heated by the water/waste heat from the combustion process.

You are not reading the temperature of the water directly.

My Kenlowe is activated from a thermo couple that is immersed in the coolant. The only time my gauge read close to the red, was when the relay that operated the fan failed. This was one reason I fitted a manual switch. I am happy with the current set-up. The gauge sits just below the half way. If the engine was to "overheat"---I use that word in the context of the engine temp. rising above normal---the gauge will indicate it.

Roger

 

[Crushers]

Roger,
you are making an assumption.

a very expensive assumption.

i would have no problem agreeing with you IF you were right but you are wrong and i am calling you on it.

here is an example, i look forward to reading your expertise in the matter:
in the winter, your coolant is running low. the engine is overheating so suddenly the temp gauge spikes for a few seconds then drops to COLD and stays there. you are still driving down the road, the gauge doesn't move and suddenly the rad hose bursts with the pressure spewing coolant all over the engine bay.

why did the temp gauge read cold when the sensor is in a "closed enviroment" filled with heated air?

 

[Roger Fairclough]

You make an assumption as to how matters will progress without logic. I base my statements on science. A garden temperature gauge is based on readings taken from the air surrounding the bubble. The temperature rises or falls and the gauge responds. This is the variation of temperature in the surrounding air. Heat can travel in 3 different ways, radiation, convection and conduction. In this case the transfer of heat from one medium to another due to variations in temperature of the mediums is conduction. This is science, not some far fetched hypothesis based on limited evidence which does not identify all the parameters.

If you need further proof that thermo couples can operate with information in gaseous form, then look no further than a gas turbine engine. You wont find any water there.

Roger

 

[Crushers]

<shrug>
typical answer.
i gave you the actual results and asked you why it happened.

now answer the question.

 

[Roger Fairclough]

Roger,
you are making an assumption.

a very expensive assumption.

i would have no problem agreeing with you IF you were right but you are wrong and i am calling you on it.

here is an example, i look forward to reading your expertise in the matter:
in the winter, your coolant is running low. the engine is overheating so suddenly the temp gauge spikes for a few seconds then drops to COLD and stays there. you are still driving down the road, the gauge doesn't move and suddenly the rad hose bursts with the pressure spewing coolant all over the engine bay.

why did the temp gauge read cold when the sensor is in a "closed enviroment" filled with heated air?

How did you know the coolant was low?

If you knew it to be low, why didn't you fill up?

If the engine was overheating, how did you know? Did you stop and check? If not, why not? Engines don't overheat that suddenly without cause.I assume by "spike", you mean a dramatic rise. This means a rapid temperature rise, and as you have low water level, the rise must be due to a rise in temperature of the AIR in the system.

You were still driving and the engine is having major problems!

Why?

If you want a scientific answer to a question, by all means ask for one, but do us the courtesy of giving scientific facts, not "does he mean this or does he mean that".

You asked for the question to be answered, and I have done so, based on the info. you have given.

Now I will ask one of you.

Do you accept that heat can travel through a gaseous medium and in so doing cause a temperature gauge to vary due to temperature fluctuations?

Roger

 

[Jon Wildsmith]

the heat is moved to the radiator for cooling by the water pump moving the hot water not by heat transfer and the sender is immersed in the hot water as it passes by. If the sender is not in the hot water it doesn't get an accurate reading because of the poorer heat conductivity and gauge tends to drop. That has been my experience of coolant loss, science or not.

 

[Crushers]

Roger,
you are evading the quesiton.
the reason why the owners didn't stop and check the coolant level is irrelevant to the original question. why it wasn't topped up is irrelevant to the original question.

if you can not answer the original question that is fine.

further:
it is common in Canada in the winter to have a DIY to mix the coolant with antifreeze to the wrong ratio, the coolant freezes in the rad. the temp gauge will spike for a few seconds (this is when you know it is overheating, duh) then it reads dead cold although the engine is still hot and over heating.
the other common issue with the DIY is the lack of burping the coolant system allowing for trapped air. when this trapped air is released then the coolant is now running low. once again the temp gauge will spike for a few seconds then drop down to cold due to the lack of fluid flowing past the sender BUT you still have a closed system with air at the sender ... why doesn't the sender respond to the high heat as the engine overheats?

i can understand if you can not answer the questions , it is common with those that have book knowledge but lack the experience.

Roger,
why did the temp gauge read cold when the sensor is in a "closed enviroment" filled with heated air?

How did you know the coolant was low?

If you knew it to be low, why didn't you fill up?

If the engine was overheating, how did you know? Did you stop and check? If not, why not? Engines don't overheat that suddenly without cause.I assume by "spike", you mean a dramatic rise. This means a rapid temperature rise, and as you have low water level, the rise must be due to a rise in temperature of the AIR in the system.

You were still driving and the engine is having major problems!

Why?

If you want a scientific answer to a question, by all means ask for one, but do us the courtesy of giving scientific facts, not "does he mean this or does he mean that".

You asked for the question to be answered, and I have done so, based on the info. you have given.

Now I will ask one of you.

Do you accept that heat can travel through a gaseous medium and in so doing cause a temperature gauge to vary due to temperature fluctuations?

Roger

 

[Chris]

I think that Roger is correct in his assertion that a gauge immersed in 100 degree water will read the same as a gauge placed in, say, an oven at 100 degrees. What I doubt is that in a coolant loss situation the probe will receive an accurate temperature 'picture' of the engine.
(Just as a thermometer placed in a sheltered spot will not record wind chill, but the temperature of the still air surrounding it.) Certainly not in the short term anyway. But I am not clear either way at the second whether it would shoot up or drop first. I rather feel that it would drop as the coolant poured out and then maybe rise with the actual temperature of the engine as it heated toward failure point. Would that heat be from air in the heater pipes? I'm not convinced. From the metal of the block? Maybe.

Interesting [strike:3nr2b7g1]argument[/strike:3nr2b7g1] [strike:3nr2b7g1]debate[/strike:3nr2b7g1], [strike:3nr2b7g1]punch up[/strike:3nr2b7g1] discussion.

Chris

 

[Jon Wildsmith]

Interesting [strike:1zqazz37]argument[/strike:1zqazz37] [strike:1zqazz37]debate[/strike:1zqazz37], [strike:1zqazz37]punch up[/strike:1zqazz37] discussion.

Out of those I prefer a discussion

i can understand if you can not answer the questions , it is common with those that have book knowledge but lack the experience.

How about we calm down a bit and have a discussion instead of sarcasm and insults

 

[Ben]

i say we test it then, as i suggested a few pages ago!

Roger if it transpires im wrong then i will hold my hands up and say so, like i always do. you only have to look at my build threads and see some of the things ive f***d up over the last few years to see that.

i try not to be one of these people who always comes across as a know it all, and if im wrong about something i will openly admit so!

 

[Iwan]

I had a 82 mk1 golf diesel and that used to overheat every day! When there was water in it the temp gauge used to be right up high when cooking.
But when the water blew out of the header tank and was low on water the temp gauge used to sit about a 1/3 up. The difference between the levels esp when it was a 1/3 up I knew it was cooking its ass off! I wasnt worried about fixing it as it costed £40!