Porsche IMS Bearing: Comprehensive Guide

Porsche IMS Bearing: Comprehensive Guide 

The Intermediate Shaft (IMS) bearing is a critical component in Porsche’s water-cooled M96 and M97 engines, and its failure can destroy an engine. For used Porsche buyers, understanding its history is key. This guide covers the IMS bearing’s evolution, its effect on engine durability, and why the MA101 engine (2009+) is the most reliable option.  

IMS Bearing Overview 

The IMS bearing supports the intermediate shaft linking the crankshaft to camshafts in M96 and M97 engines. Early versions were failure-prone, often causing severe internal damage. Here’s the technical progression:  

1997-2001: Double-Row M96 IMS Bearing  

  • Engine: M96  

  • Design: Double-row bearing  

  • Years: 1997-2001  

  • Reliability: Poor—wear and failure common, some as early as 40,000 miles  

  • Notes: Verify replacement history. If original, deduct $4-5k from price for maintenance.  

  • Recommendation: Avoid or budget for replacement. 

 

2002-2005: Single-Row M96 IMS Bearing  

  • Engine: M96  

  • Design: Single-row bearing  

  • Years: 2002-2005  

  • Reliability: Better than double-row but still failure-prone  

  • Notes: Issues less frequent, yet repairs remain costly.  

  • Recommendation: Plan for preventative maintenance. 

 

2006-2008: Single-Row M97 IMS Bearing (Larger Diameter)  

  • Engine: M97  

  • Design: Single-row, larger diameter  

  • Years: 2006-2008  

  • Reliability: Improved durability over M96, but not immune—personal M97 unit failed despite aggressive maintenance.  

  • Notes: Replacement requires engine disassembly, adding cost.  

  • Recommendation: Decent option, but weigh disassembly risk. 

 

2009+: No IMS Bearing – MA101 Engine  

  • Engine: MA101  

  • Design: IMS bearing eliminated  

  • Years: 2009+  

  • Reliability: Top-tier—no IMS failure risk  

  • Notes: Found in 2009 Cayman, 997.2 911, 2010+ Boxster.  

  • Recommendation: Best for long-term, low-maintenance ownership. 

 

M97 Specifics (2006-2008) 

The M97’s larger IMS bearing is a step up from M96, but non-serviceable without engine teardown. It’s more reliable than earlier designs, yet the MA101’s no-IMS approach beats it for simplicity and cost.  

Why MA101 Wins 

The MA101 engine (2009+) ditches the IMS bearing, eliminating its failure mode. Result: higher reliability, lower ownership costs. It’s the go-to for buyers prioritizing durability.  

Conclusion  

  • 1997-2001: Double-row M96—high failure risk.  

  • 2002-2005: Single-row M96—still problematic.  

  • 2006-2008: M97—better, but disassembly looms.  

  • 2009+: MA101—no IMS, no worries. 
    For minimal headaches, target 2009+ MA101-equipped Porsches. Know the IMS history, and you’ll pick a solid engine.