Start Up Rattle - Part Upgrade to Eliminate

[Seadweller]

Originally Posted by 911monty

He is talking about the Intermediate shaft to crank chain tensioner with the external spring that Porsche upgraded in 01-02, helps prevent tensioner relaxing/collapsing while sitting. My 98 has one installed should work fine in yours.

Edit This part https://www.pelicanparts.com/More_Info/99610518058.htm?pn=996-105-180-58-M100&SVSVSI=1049&DID=13597

I understand there's 3 tensioners, but can just this one part be replaced/updated, and did it cure the rattle?

[Radman]

Originally Posted by Seadweller

I understand there's 3 tensioners, but can just this one part be replaced/updated, and did it cure the rattle?

Fair warning that the part says it is only applicable to 2001 and newer.

[ike84]

Originally Posted by Radman

Fair warning that the part says it is only applicable to 2001 and newer.

Rad is right. I read that tsb, it actually specifically says that the parts are not to be intermixed. There are certainly a few people who have done that swap though and it seems like no one killed their motor in doing my so.

I'm all for updating parts, but with the available evidence this seems a bit sketchy to do.

This may be a silly thing to say, but who cares about startup chain rattle? If the ramps are good, your cam deviations are good, and the oil pressures are fine I personally think this is a non-issue.

Sent from my POCOPHONE F1 using Tapatalk

[Seadweller]

Originally Posted by ike84

This may be a silly thing to say, but who cares about startup chain rattle? If the ramps are good, your cam deviations are good, and the oil pressures are fine I personally think this is a non-issue.

Sent from my POCOPHONE F1 using Tapatalk

I would tend to agree, and perhaps I'd feel more comfortable if I knew exactly what was causing the rattle. Is it isolated to the chains themselves, or is it the chains slapping against the ramps? I would think over time, if the chains are slapping the ramps, it would cause excessive/premature wear, and possibly even failure.

[JFP in PA]

Originally Posted by ike84

Rad is right. I read that tsb, it actually specifically says that the parts are not to be intermixed. There are certainly a few people who have done that swap though and it seems like no one killed their motor in doing my so.

I'm all for updating parts, but with the available evidence this seems a bit sketchy to do.

This may be a silly thing to say, but who cares about startup chain rattle? If the ramps are good, your cam deviations are good, and the oil pressures are fine I personally think this is a non-issue.

Sent from my POCOPHONE F1 using Tapatalk

This oil pump spring and valve upgrade was implemented to address low oil pressure problems at idle when fully warmed up and using their "recommended" piss thin oils. It was never designed to address any cold start up noise issues.

[911monty]

Originally Posted by ike84

Rad is right. I read that tsb, it actually specifically says that the parts are not to be intermixed. There are certainly a few people who have done that swap though and it seems like no one killed their motor in doing my so.

I'm all for updating parts, but with the available evidence this seems a bit sketchy to do.

This may be a silly thing to say, but who cares about startup chain rattle? If the ramps are good, your cam deviations are good, and the oil pressures are fine I personally think this is a non-issue.

Sent from my POCOPHONE F1 using Tapatalk

Just how silly? Who cares? Apparently Porsche engineers did. In fact per the following technical bulletin the change was made to specifically address noise.

5 chain.pdf

As far as sketchy goes, The changes per the technical bulletin was moving from a roller to a tooth type chain requiring a change to the crank and IMS drive sprockets, these obviously are not interchangeable and the TSB makes sure to address this. The change to the Tensioner was to add an external spring to help during startup. Even though not mentioned in the Technical bulletin there were improvements to the chain paddle. However the point the chain tensioner contacts on the backside of the paddle that has no interaction with the tooth type chain remained the same black plastic pad in the same location.

Personally I see this as an mechanical improvement unlike a 1200 cfm square bore .