Thermostat

Just gone to replace my thermostat ,thing is gasket was there but no thermostat ,is there any reason why someone would take it out ?(only owned this 200 tdi for a month)

Nobby2012 said:

Just gone to replace my thermostat ,thing is gasket was there but no thermostat ,is there any reason why someone would take it out ?(only owned this 200 tdi for a month)

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Possibly the thermostat failed in the closed position causing the engine to get hot, the previous owner then removed it. Best replace, as it will help the engine to heat up to the optimum operating temperature (also supply heat more rapidly to the heater matrix)

Nobby2012 said:

Just gone to replace my thermostat ,thing is gasket was there but no thermostat ,is there any reason why someone would take it out ?(only owned this 200 tdi for a month)

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Usually because the car's been running hot for whatever reason. Which could be caused by anything from leaks in the system, a clogged rad, a bad water pump, bad pressure cap, etc......

Put a new thermostat in ,it just baffled me why there wasn't one in .will give it a good run tomorow and see what it doe's

Keep a good eye on the temp gauge

Daz

discovery1-daz said:

keep a good eye on the temp gauge

daz

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+1

If it starts been silly should I remove it?

Maybe the previous owner didnt have the right sensor for the conversion and it was constantly on Hot?

Nobby2012 said:

If it starts been silly should I remove it?

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If it's in I'd cautiously drive it to see if I had an issue with overheating. Keep an eye on the gauge.

Why were you replacing the thermo in the first place?

Without a thermostat you have no chance of maintaining (or even reaching) the correct running temperature, if it is getting hot then you have a bigger problem than a missing thermostat which has been removed to cover up the problem and not cure it.
A thermostat allows the engine to warm up by keeping the coolant in a closed system circulating it around just the jacket & heater, at this stage it is not flowing through the radiator. As soon as the operating temperature of the thermostat has been reached the thermostat opens and allows the (now hot) coolant to flow through the radiator which lowers the temperature to below the operating temperature of the thermostat so it closes again thus allowing the coolant to warm up. This goes on all the time the engine is running and maintains a constant water temperature.

If you have no thermostat fitted then there is every chance that the engine will never get up to the correct operating temperature as it is constantly being cooled (over-cooled in fact) but if it is then you have a fault which needs to be sorted rather than being covered up.
Is the engine actually hot or does the gauge just say it is?
Is the rad the correct size and if it is, is it blocked or the fins damaged?
Is the coolant circulating & pressurising correctly?

As already stated, it might (hopefully) just be that it failed for some reason and the previous owner couldn't be bothered to get a new one (worrying as what else might they have done in the name of "maintenance"?).
Keep an eye on it and perhaps check the gauge accuracy.

It's not run hot ,I drive 100 down motorway to visit my son and the gauge will bearly reach even the White on the gauge

Needle should be 1/2 way on the gauge at normal running temp if the gauge and sender are good. Have a search on how to bleed the coolant - if you're not 100% sure how to do it properly.

Daz

Just done about 40 mile and needle settled at 3/4 just on the edge of the White on the dial ,does the collective think that will be ok ?

Nobby2012 said:

Just done about 40 mile and needle settled at 3/4 just on the edge of the White on the dial ,does the collective think that will be ok ?

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What's your weather like today? Cool and moist, or warm and sunny?

Mind you I drive a 4.2 petrol, but my gauge stays just shy of half way all the time so if it's coldish outside you may have an issue if it's sitting at 3/4.

Warm and sunny ,got a 100 drive back to Penrith tomorow ,so I'll either get there no problems or on the back of a recovery truck

Nobby2012 said:

Just done about 40 mile and needle settled at 3/4 just on the edge of the White on the dial ,does the collective think that will be ok ?

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Like I said in my earlier post, is it actually getting hot or is it just a gauge reading and if so, how do you know the gauge is accurate?
With an engine transplant the sender & gauge may not be matched.

To my knowledge and the service history it isn't a replacement engine ,before putting new thermostat in the gauge didn't even move from rest

My mistake.
When looking through the other posts I saw one about a conversion (No.8) and it stuck in my mind.

Is your heater hot? If so it should be circulating ok, you could feel the back of the head see if it's hot etc.

The gauge if you pull the temp sensor wire off and put to earth ignition on it should sweep over to hot and stay there without jumping about or dropping, this will give you some idea how well it works.

Water pump impellers can throw a blade not trying to worry you this would not circulate properly.

The heater is a lot hotter than before I fitted it ,before I fitted it the heater was hardly warm at all would say about 30c