944 Turbo L4-2479cc 2.5L SOHC Turbo (1988)
Engine Mount: Testing and Inspection
CHECKING HYDRAULIC ENGINE BELTS
General Information
Hydraulic engine mounts cannot be tested 100% with conventional workshop equipment. However, the test procedures listed below can be used to
determine whether hydraulic engine mounts are defective or seriously impaired in effectiveness.
Of the two hydraulic engine mounts, the one on the right is subjected to greater thermal loading and thus more likely to give cause for complaint.
Checking
Symptoms indicating a damaged engine mount:
- Clearly-discernible knocking or vibration while starting and/or turning off the engine.
- severe engine vibration in idle (with engine in perfect condition and balance shafts adjusted correctly).
- no or insufficient spring travel when pulling down on engine. Specification: 2 - 3 mm. (Do not check left and right hydraulic engine mounts together.
Use exhaust pipes for leverage).
- Visual inspection shows leaks (mounts are filled -with a damping fluid), rubber peeling off, cracks, or notching.
- Height of removed and de-tensioned hydraulic engine mount is less than 65 mm (new 70 + 1 mm) measured between bearing surfaces.
(Height of installed hydraulic engine mount not less than 62-2 mm)