Product Information
Product Information
Engine mount
Part number 987.375.023.05 (often written 98737502305) is
the centre engine mount / mount insulator used on mid-engine Porsche
Boxster/Cayman models, commonly fitted to late 986 and 987 Boxster / early 987
Cayman applications. The item is offered both as the complete mount and bracket
assembly and as a replacement bushing/insulator that must be pressed into the aluminium
bracket.Position: center engine mount (the central mount that
locates the engine fore/aft and resists torque).
Fits:- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 2.7L 2005 -08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08
Replace the part when it has lost its ability to control
engine movement and damp vibration. Typical triggers to replace the centre
mount include:
- Hard clunk or bang on acceleration, deceleration or gear
changes (engine shifting against chassis).
- Excessive vibration into the cabin, especially at idle or
specific RPM bands.
- Visible damage — torn, separated rubber, oil-soaked or
collapsed mount/bushing, or corrosion of mating faces.
Common issues & failure causes
- Rubber deterioration: age, heat cycling and mechanical
fatigue cause the rubber to harden, crack or de-bond from the metal, reducing
isolation and allowing increased engine movement.
- Fluid contamination: oil or coolant leaks accelerate rubber
breakdown (softening or swelling), commonly seen on older engines where leaks
occur.
- Mechanical shock / abuse: repeated hard launches, aggressive
shifting or collisions can cause sudden mount failure or promote early fatigue.
- Bracket wear / corrosion: the bushing may be fine, but the
aluminium bracket can crack, corrode, or the bushing may need pressing into a
worn bracket — which is why some techs prefer replacing the full assembly.
This product supersedes Porsche's old part numbers:
- 98737502304
Click 'Zoom in' for large parts diagram.
Diagram Ref No 2.
Related reference numbersRelated, superseded, cross reference or alternative numbers for comparison.
98737502305 98737502304
98737502305
98637502307
The product you are viewing cross references to these numbers