Timing chain tensioner, crank to IMS - Porsche 911 type 996 / 997 2001-2008, Boxster / Cayman 986 / 987 2001-2008

Porsche

Genuine Porsche timing chain tensioner for later single-chain M96 / M97 engine cars, delivered between 2001-2008. This is not for use on the earlier production dual-chain M96 equipped 911 and Boxster models unless they have had an updated engine installed.

Fits:

Porsche Boxster / Boxster S type 986, 2001-2004
Porsche Boxster / Boxster S type 987, 2005-2008
Porsche Cayman / Cayman S type 987, 2006-2008
Porsche 911 C2 / C4 / C4S type 996, 2001-2005
Porsche 911 C2 / C4 / C4S type 997, 2006-2008
*Please note: Since some earlier cars may have a later production replacement engine with the single row timing chain this part may also fit 1997-2000 Boxster and 1999-2000 911 if they have had an engine update.

Notes:

Latest available revision.
For single-chain M96 / M97 engines only.
For crankshaft to intermediate shaft.
Single groove cut into head indicates position.
Professional installation recommended.

On the M96 / M97 family of engines from Porsche there are three timing chain tensioners which keep the crankshaft, camshaft banks and intermediate shaft in time and operating correctly. Porsche has released multiple updates on these over the years, and this is one of the most simple and relatively inexpensive maintenance updates which can be performed to help with long term reliability.

As the tensioners wear from use and mileage the piston will score and over time which this can lead to binding. Significant cases of tensioner binding or excessive slop (rattling) will increase the stress and tension on the timing chain and components, and in the most severe cases can break the chain. If this occurs on the primary crankshaft to intermediate shaft chain it can lead to catastrophic total engine failure, on occasion. If it occurs on one of the camshaft bank timing chains the damage can vary, but will always be costly.

A tell-tail sign of worn or less-than-optimal tensioner condition is a 'rattle' sound at start up and when cold. Generally speaking if your Porsche's engine begins to have a 'rattle' at cold start this could be an indication of weak or worn tensioners. The tensioner is pumped up by oil to maintain proper pressure and worn tensioners will typically bleed some of this pressure off after sitting for some time, resulting in this momentary rattle from having too little tension.

As a rule of thumb if you have had your M96 or M97 Porsche 911, Boxster or Cayman for some years and are unsure if the tensioner update has been done, or if you have a rattle at cold start, or are having an IMS bearing update procedure being done it is ideal to inspect and if necessary replace these three tensioners. Visible scoring on the tensioner piston, as shown above, is a good example of a worn tensioner needing replacement.