VW Scirocco - coolant loss caused by pump seal

With the above-mentioned vehicle type, it can happen that coolant is being gradually lost. This can become obvious as a result of increased engine temperature, by a warning message for the coolant level or by a level shown that is actually too low.

The leak often only occurs when the engine is warm, which makes diagnosis more difficult. The engine coolant pump is a complex module with an integrated thermostat and plastic housing. Thermal stress can cause the seal to age and leak, which usually results in minimal, barely visible leakage.

In order to carry out diagnosis, the coolant level should first be checked and the cooling system inspected for traces of fluid loss. As the leak usually only becomes visible when the engine is at a warm operating temperature, a visual inspection after a test drive is recommended.

Particular attention should be paid to the engine coolant pump, as leaks often occur in the seal area. A pressure test of the cooling system using a test device can be carried out if necessary in order to unmistakably detect even the smallest of leaks.

If there is anything conspicuous that might indicate a loss of coolant in the pump area, replacing the coolant pump seal in accordance with the manufacturer's specifications can provide a remedy to the problem.

Because of the repair work involved, we recommend replacing the entire pump unit including all seals. After the repair, the cooling system must be vented in accordance with the manufacturer's specifications and checked again for leaks.

Reprinting, distribution, reproduction, exploitation in any form whatsoever or disclosure of the contents of this document, even in part, is prohibited unless our express permission has been obtained in writing beforehand and the source is stated. The schematic illustrations, pictures and descriptions are provided for explanatory purposes and are only intended as a visual supplement to the document text, so they cannot be used as the basis for installation or assembly work. All rights reserved.