Jump to content

Server Lease Renewal/Software Licenses

Our yearly server lease, software licenses, as well as hardware operating costs, ARE due Dec 6th, 2021. Our current donations have fallen far short of the funds we need to renew. Please remember the RennTech.org community is Member supported so please consider a donation to help...  THANK YOU!

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Loud Rattle on Cold Start

Recommended Posts

I have a 2000 Carrera 2 that has a loud rattle on cold startups that lasts about two seconds. I cannot reproduce the rattle after the car has run for a few just a few seconds, leading me to believe that it is oil pressure related. After the car is run, even for very short periods of time, the car will have to sit for several hours to reproduce the sound on startup. An additional symptom is what sound like a "Lifter Tap" from a Chevy V-8 with the rocker arms out of adjustment. My initial thought was that it was the "Death Rattle" and I needed an IMS. I did a full engine-out last month. The car was on the original clutch, and I thought I needed an IMS. The engine had never been out of the car so I decided to give it a thorough going over and change all of the cooling hoses. They were 11 years old and I did not feel like pulling the motor again over a $20 hose so I did all of them while I was in there. I replaced the clutch, bearing, flywheel bolts, etc. and upgraded to a LN Ceramic IMS while I was in there. Everything went together fine and the car runs great, except I still get this rattle on cold starts.

I decide to pull the motor again and get to the bottom of it. The "tap" seemed to be louder on the passenger side, so I pulled that valve cover first. After a thorough examination, I could not find any sign of wear. My thinking was that I have a bad valve tappet, noting that they are hydraulic. This would explain the rattle on cold start up and the elimination of the problem with full oil circulation. However, I thought I would find some sign of wear upon close examination of the valve train. There was no visible wear on any of the cam lobes and no sign of excessive wear on the tappets (that does not mean the wear could not be visible from the bottom of the tappet that I cannot see). Just to be sure, I pulled the cover on the IMS to make sure the first row of the bearing was not showing signs of wear. The new IMS looks fine, so I am ruling that out.

As this is the first 911 I have owned, I was wondering if anyone with a lot more experience with these engine’s has encountered a similar problem, or has any thoughts on how to get to the bottom of this mystery. Any help or idea would be greatly appreciated.



Link to comment
Share on other sites

Rattles on start up are often the chain tensioners on the IMS to crank chain or the IMS to cam chains. As they get old they leak down when the engine is off and take a second or two to pump up when the engine is started. This allows the chains to rattle. You can all three for only $200-$300 and they can be replaced with the engine in the car. The only one that is difficult to change is the one on the 4-6 side at the rear of the car on the top as you have to remove the AC compressor. As you have dropped the engine you know how to remove this.

Fairly inexpensive DIY that will probably fix the problem.

Link to comment
Share on other sites

Thanks for the help! I pulled all three tensioners when I got home tonight (see pics). 1-3 is the softest and I can compress it fully with a good squeeze, with no oil coming out. 4-6 and the IMS only allow me to compress them about a half-inch with a good squeeze then they stop hard. Both of those are ejecting oil as I push. Based on the 1-3 being dry and compressing fully, I'm guessing that is the culprit. The difference in resistance across the three tensioners is reason enough to replace all three of them.

Thanks again for the help...........Chris



Link to comment
Share on other sites

  • 5 years later...

Hi miscou,


Did the noise go away after you replaced the three tensioners  ? I have a similar rattle noise on start up but only seems to happen after the engine has been warmed up a little. SO I am considering replacing the tensioners as it doesn't seem to be a big job.. I made a shot video to show the difference https://youtu.be/9ZJ064bh7ko


Link to comment
Share on other sites

  • 3 weeks later...

I did not expect a reply form  miscou, since this is such an old thread. So I got my local Porsche dealer to replace all three tensioners. I did not want to do the job myself as there was a risk I cold mess things up. Now I can confidently say loud rattle noise during start up is completely gone. The engine also seems to run quieter overall. 

Link to comment
Share on other sites

  • 8 months later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Content

    • By OscarAH1W
      I am completely flummoxed by this noise I am getting in my 2004 Turbo Cab.  A couple nights ago while driving home with the top down, I noticed a rattle different from the normal sound of the motor and not accelerating/decelerating with changes in engine RPM.  It occurred at 1800-2000 rpm and was most noticeable when decelerating in 2nd gear in my neighborhood at slow speeds (~20MPH)...  with a helper on the throttle and the engine compartment open, it sounds like it is coming from the right side-top of the engine, around the Hydraulic reservoir.  Putting a spanner/wrench on the component and up to the temple seems to have confirmed this as the source.  I checked my manual and the Pentosin level (mid range on the HOT side of the dipstick at operating temp)  I realize that Porsche recommends checking at 20C but I live in Texas now and that won't happen until November.  Just out of curiosity I looked at the clutch reservoir up front and after removing the gooey trim cover, found it leaking (Seeping) from the recently replaced cap and appearing to be overfilled.  The car has never really been operated in the 8 years I have had it in particularly high average temperatures, so I am hoping that the front is thermal expansion.  Any thoughts on this matter are greatly appreciated... Loren?  What Say You??
      Thanks in advance,
    • By jeremi
      I have a 2006 3.2 Cayenne. When I accelerate normally the engine sounds slightly like a diesel until i reach 1900 to 2000 rpm. If I accelerate fast I also get loud engine rattle noise at around 3000, if  I drive normal the rattle is not very prominent. No power loss shifts smooth. The engine rattle noise does increase with rpm but disappears around 4000 rpm when car shifts. No rattle at 3000 rpm normal acceleration. Any thoughts? 
    • By bigscotia10
      I'm getting a weird buzzing noise (buzz/whine) when above 4000 RPM. It's a 997S 1st gen no mods, with about 70k on it. It sounds a bit like the car is struggling at anything past 4000 RPM.. It happens in gear and in neutral. When its hot and cold. if anyone has any ideas of parts I should look at, that may be causing this, please let me know!
      I'll post a video of the sound in the next couple of days too, so you can hear what it sounds like.
      Thanks a lot!
    • By Bruce in Philly
      With my Boxster S, it was the lateral arms... the ones that goes front to back. In the 197K miles of ownership, I think I replaced at least all of them twice and a few three times.

      My 2009 C2S has a clunking/rattle in the right rear. I had it up on jacks and could not find it. I checked the three bolts on the top of the struts, I put a tire iron in there and twisted and wedged and no joint/bushing moved more than the others.

      I am very sure it is a control arm. So, unless someone in Philly has some chassis ears they can lend me for a day, I want to just replace the most common offender. 997 331 043 01

      So, which rear control arm goes first?
      Anyone know the torque values for this part?

      Bruce in Philly
    • By 01slvr996
      I'm sure this has been covered, and maybe I'm blind, but I've got quite the cold start rattle and want to look into changing out my tensioner's, the car is an 01 c2 cab, factory IMS, 97k miles and runs great. Is there any guide or maybe some tips to doing this? help would be appreciated!
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.