Date:         Tue, 22 Nov 94 15:20:46 EST
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         wigley@server.uwindsor.ca (Neil Wigley)
Subject:      Re: gerry's thermostat and translation pblm


Well here's my two pfennigs worth. It would help if I knew what ventilteller
(butterfly valve?) and O:ffnunghub (capacity of opening?) are. But here goes:

The thermostat

Stated simply, the thermostat determines whether the coolant in the radiator
at the front of the vehicle should be cooled off or not. It also has the say
over whether the coolant should circulate in the 'small' or in the 'large'
coolant circuit (see page 72).

Of course the thermostat controls the flow of the coolant in connection with
the coolant temperature. That occurs through athe other hand, if the operational temperature should drop,
then a spring on the thermostat presses the valve-plate again in the 'closed'
direction and blocks the flow of cold water until the operational temperature
prevails again.

Condition of the trouble
Thermostat

Recognition sign                                Cause/effect
--------------------------------------------------------------------------
Temperature indicator climbs slowly,       Thermostat valve-plate is blocked 
temperature is reached later,              in the 'open' position (perhaps
insufficient heater effect                 due to deposits. In the
                                           short run there will be no damage.
                                           Despite that change the thermostat
                                           soon.

Temperature indicator remains in the       Thermostat valve-plate is blocked 
red despite the correct coolant            in the 'closed' position (perhaps
quantity, coolant warning lamp blinks      due to a defective or leaky thermo-
                                           stat 'tin can'). Under no circum-
                                           stances drive farther, otherwise
                                           considerable heat damage to the 
                                           engine will arise. Change the
                                           thermostat.

Helpful hint: If the engine should boil over while driving due to a defective
thermostat, the only help is to towing or the complete replacement of the
thermostat right then and there. If you decide for the replacement, then
you must first wait until the coolant temperature sinks to a tolerable level.
Otherwise there is a danger of scalding (Ed. note: Duh! Sometimes the Germans
can be so damned pedantic.). Take care to use the requisite vessels to capture
the coolant.

Exchanging the thermostat

The exchange of the thermostat is identical for both gasoline and diesel:
* Let the coolant cool off, otherwise scalding danger.
* Remove some of the coolant (see page 74).
* Remove the lowest coolant hose from the thermostat housing.
* Gasoline: Screw off the heat shield from the hose.
* Loosen two hex screws underneath the thermostat housing and remove the lower
  housing lid.
* Take out the thermostat.
* When replacing, the spring in the thermostat must lie on top.
* Use new seals for the thermostat housing.

Checking the thermostat

With a preserving thermometer (as in preserving peaches, etc.) you can check
yourself whether the coolant thermostat opens at the prescribed temperature.
Here are the data: Starts to open at 85 C. Completely open at 105 C. The full
opening capacity (?) amounts to at least 8mm (gasoline) resp. 7mm (diesel).
* Remove thermostat.
* Hang the thermostat in a pot of water and heat the water.
* Check whether the valve-plate lifts off from its seat at the right
  temperature or respectively whether it's fully opened.
* Check the total opening capacity (?).

End of translation. Amazing how coarse it sounds in English.

Neil Wigley