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Old 09-20-2013, 07:16 PM   #43 (permalink)
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Black Beast - '02 VW Goff Estate S
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It's also interesting that my thermostat may not get hot enough to activate. I'm wondering if the NA and turbo engines have different temperature settings as my temp gauge stays a pretty constant 74 degC?
I can't think of any reason why the SDi should be designed to run at a different temperature from the TDi. All engines I have ever known, whether petrol or diesel, have had thermostats that open about 87 degrees, giving a regulated temperature of 90+ degrees.

(As I understand it, engines would be happier running even hotter, but the practical limit has always been the boiling point of the water used for cooling. Even under pressure, the coolant (mostly water) can't be much hotter than 100 degrees (well, 110 is probably fine) without local boiling happening in the hotter parts of the engine. Thus engines are designed to run at a little under the boiling point of water. Users of Evan's Waterless Coolant sometimes advocate slightly higher engine temperatures as that stuff boils at 180 degrees C (?) even without pressurisation.

As I said earlier, the thermostat I removed last year was operating - i.e. opening and closing - but it was beginning to open at 65 degrees rather than 87. My guess is that your thermostat is simply faulty and needs replacing. I would check that, and put a working thermostat in before doing any grille blocking. Very simple to check in case you haven't done that before. At the temperatures your engine is running at, the thermostat shouldn't open at all, ever, and virtually no heat should be going to the radiator. If the hoses to and from the radiator are hot or even decidedly warm when Scanguage reports a coolant temp of below 87 degrees (or whatever the opening temperature of your thermostat should be if it's different, but I'd be willing to bet it's the same as the TDi) then your thermostat is faulty.

Last edited by paulgato; 09-20-2013 at 08:47 PM.. Reason: removing a comma
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