Passat 1.8T vs 2.0 TDI comparo: thermostat function....

Jan 21, 2008 8 Replies
K

Greetings, aficionados:



Lucky enough to have a brace of 2005 Passat wagons (estates for those in the UK/Aussie..), one a 1.8T 4-motion gas and the other (preferred) a 2.0 TDI with waaaaaay more grunt.



Here in Nova Scotia, seasonal temps are dipping to -10 degrees C and colder.... and the TDI takes a LOT longer to warm up than the 1.8T. Like at least twice the distance driven (I've swapped cars out for the same commute to work...) for the TDI to start giving faintly warm air out of the vents. Doesn't *act* like a stuck T-stat (with sudden surge of temp/hot air), , and still does get the water temp to 90 degrees C, just noticeably slower than the other car.



I can't see why there should be a (significant) difference between the two, simply based upon the different engines (lower specific heat of diesel??)....... and would appreciate any experience/opinions...



Cheers,


Kevin Halifax, NS


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E

The diesel engine is much more efficient and has less waste heat than the gas engine, therefore takes longer to heat up. Turn the heat control all the way to hot on the diesel. There's a set of glow plugs in the coolant stream that help to heat the coolant to bring it up to temp. You may also need to have them checked to make sure they are operating corectly.

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J

The glow plugs are in the combustion chamber to warm things up for slightly easer starting. They run for a few seconds. If the glow plug light is off then the glow plugs are off. Of course assuming not faults that cause the glow plug light to stay on indicating a problem. The glow plugs have nothing to do with the coolant and oil warming up faster.

My diesel takes a lot l>The diesel engine is much more efficient and has less waste heat than the

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L

What Erik said, plus installing a block heater should give you a head start for heat.

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E

In addition to the glow plugs in the combustion chamber for starting the engine (in temps below 40 degrees F), the TDI's ALSO have a set of 3 glow plugs in the coolant to warm the engine quicker. I know, I have one. See Bentley manual section 28b-3 & 4.

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E

It's not a block heater. Check in the ignition section of your bentley (sounds silly, but that's where they're referenced in my copy for my 2001).

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K

Thanks for the help.... will "look into" the coolant heaters/etc!

KB

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