Logic behind removing thermostat?

[Imamember]

In short, car hasn't been getting up to temp since I bought it, finally replaced the thermostat yesterday except on replacing it... the thermostat was missing! :nono:

Any logic behind taking it out? Perhaps trying to hide an underlying problem!?

(Car has done 300 miles since the thermostat change, gets up to temp nicely, coolant is OK etc...)

 

[Amos91]

If it was stuck shut and overheating it could of been removed as a temporary fix and then not bothered to replace...

 

[Imamember]

Yeah thats the only explanation I could think of; for the sake of a fiver though you'd think they'd replace it!

 

[scotty10]

Daft question time, what's the difference between the coolant temp sensor and thermostat ?

And if faulty, are the symptoms the same.

 

[GrahamS]

It was missing? maybe trying to cure a leak. That's weird.

Tempsensor just reads the coolant temp but doesn't affect the opening of the thermostat.

The thermostat is controlled by wax which opens the stat at 90 degrees or so. Corse VXR runs a high temp stat. Some people run low temp but the standard is good for almost every use you can think of.

Symptoms of a broken stat will be over heating or otherwise the car will never heat up unless sitting in traffic

 

[Dan@SJM]

Can be a trick of covering up a car that's over heating a lot.

 

[Chip-mk1]

Daft question time, what's the difference between the coolant temp sensor and thermostat ?

And if faulty, are the symptoms the same.

Thermostat is a physical valve that opens and shuts to allow or stop the flow of water, its not electronic in anyway, its not controlled by the ECU or anything else external, it relies purely on heat to open it.
You can test one by dropping it into boiling water and seeing if it opens.

Coolant temp sensor is an electronic thermometer that tells the ECU what temperature the coolant is at.

 

[ben_r1]

You'd imagine in this day and age thermostat technology would have advanced to an actual electronic valve that can be more accurately controlled by the ECU...

 

[Chip-mk1]

You'd imagine in this day and age thermostat technology would have advanced to an actual electronic valve that can be more accurately controlled by the ECU...

I see no real advantage TBH, you want it to open at one specific temperature always, so why introduce another point of potential failure?

 

[ben_r1]

I see no real advantage TBH, you want it to open at one specific temperature always, so why introduce another point of potential failure?

A thermostat is either open or closed though, an electronic valve can be partially opened or closed to keep the engine closer to its target temp for longer?

I don't really have any knowledge to back that theory up although some of the Merc Econics i have at work are equipped with two thermostats side by side, one is rated 10 degrees lower than the other so there must be an advantage to partially opening the flow?

 

[Chip-mk1]

A thermostat is either open or closed though, an electronic valve can be partially opened or closed to keep the engine closer to its target temp for longer?

The water temperature doesnt change massively quickly because its got a high specific heat capacity.

I can understand what you are saying though, just not something I can see an application for in a clio type environment thats all.

I don't really have any knowledge to back that theory up although some of the Merc Econics i have at work are equipped with two thermostats side by side, one is rated 10 degrees lower than the other so there must be an advantage to partially opening the flow?

Interesting, again I cant personally see a reason for it particuarly, as each engine as an optimum operating temp and you generally want to hit it as soon as possible, unless the two circuits being opened do different things in some way, like the water is used to heat some external system first or something. (cars have a bypass for this for the heater for example, although not with another thermostat)

 

[GrahamS]

2 thermostats could be used to have a heaterbox which is able to pump out some serious heat but the coolant in the block nice at 90

Guess

 

[Dan@SJM]

You'd imagine in this day and age thermostat technology would have advanced to an actual electronic valve that can be more accurately controlled by the ECU...

Have you seen the Peugeot 308's? They have them. I see atleast 1 a month that's fucked. Had one in last week on a 61plate. More than half a decade they have had wax thermostats. They work, they work well. Why change them?????

 

[Chip-mk1]

Half a century I take it you mean

 

[Dan@SJM]

Or that lol.

 

[ben_r1]

Many things worked perfectly fine on older cars that have been replaced with more complex and unreliable designs...

 

[Chip-mk1]

Many things worked perfectly fine on older cars that have been replaced with more complex and unreliable designs...

Indeed, but always driven by emissions, I see no emissions advantage in not bringing the engine upto temp as soon as possible.

Anyway, we are probably digressing a bit much from a thread about the 172 thermostat, lol.

 

[ben_r1]

But we all love a good engineering discussion