COOL-07, Water Pump Information and Replacement
Other Procedures Needed
There are two different styles of water pumps used on the 924S and 944 (including Turbos). The new style coolant pump has a guard rail for the timing belt an a larger idler roller (46.2 mm vs. 32.0 mm). The new style was installed on all cars produced after July 1986. I recommend installing the new style pump when replacing the water pump. For cars which previously did not have the new style pump installed, this requires modifying the rear timing cover and purchasing a belt guard and larger idler roller. Some of the new style pumps will come with the belt guard already installed so ask your parts supplier when ordering. The groove for the thermostat snap ring has also been moved. Previously, it was 4.5 mm from the sealing surface and is now at 7 mm. This requires the use of a new thermostat and spacer.
On Turbocharged cars, there is a nozzle on the water pump which supplies cooling water to the turbocharger bearing housing. On Normally Aspirated cars the nozzle is a block-off plate. The block-off plate / nozzle is sealed to the water pump by an o-ring which should be replaced when the new pump is installed. On some pumps, the block-off plate / nozzle is mounted using a 6 mm stud and nut and a 6 mm x 20 mm bolt. However, most of the new pumps come with two bolt holes. This requires transferring the 6 mm stud from the old pump to the new one or purchasing another 6 mm x 20 mm bolt.
Model Old Style Pump New Style Pump 924S, 944, 944S 944 106 021 13 951 106 021 10 944 Turbo 951 106 021 01 951 106 021 10
New Style Pump Part Number Water Pump Gasket 1 944 106 132 04 Guard Rail 944 105 213 01 Guard Rail Lock Nuts (2) 999 084 092 02 46.2 mm Roller 944 105 241 03 Block-off Plate / Nozzle Part Number Block-off plate (NA cars only) 944 106 313 00 Nozzle (Turbo Only) 951 106 313 00 Thermostat for Turbocharger 951 106 311 00 O-Ring (NA or Turbo) 900 174 049 40 or 999 707 283 40 Washer (2) N 011 524 7 Bolts 6 mm x 20 mm (2) N 014 704 1 Thermostat Part Number Thermostat (New) 944 106 019 00 Thermostat (Old) 944 106 129 05 Spacer (New Style Pump) 900 234 160 00 O-Ring (New Thermostat) 944 106 929 08 O-Ring (Old Thermostat) 944 106 929 05 Thermostat Snap Ring 900 042 025 01
1 Normally, a new gasket will be provided with any new or rebuilt water pump. However, when ordering your pump, you should ask if the gasket is included.
Tip: This is a good time to inspect and replace the crankshaft and balance shaft oil seals.
On the newer style water pump, the gap between the thermostat sealing surface and the snap ring groove is 7mm. This will require the newer style thermostat and sealing ring. It will also require installation of the 2.5mm support washer between the snap ring and the thermostat. The older style water pump has a 4.5mm gap between the thermostat sealing surface and the snap ring groove and requires the older style thermostat and sealing ring without the support washer.
The factory manual has you install the water pump fasteners using Loctite 270. This is fine for the nuts. However, I prefer to not use it on the bolts as is increases the probability of stripping the bolts holes during the next removal.
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