Jump to content

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)
gojerry

Knocking on front end after 30 mins driving

Recommended Posts

 I have  an 03 Boxster with 95k on the clock.

When you first start driving the car, everything is tight and quiet. After about 25 - 30 miles, the front start to knock lightly and rumble. Most noticeable between 0 and 30mph in queuing traffic.  You can feel the knocks on the steering wheel and brake pedal. The further you go the worse it gets. The sound is like a bolt being jarred in a plastic bottle.

Up to now it has had new bake disks and pads. Track rod ends and wishbones replaced and something That looks like coffin struts changed. Wheels and tyres have been checked. When the knocking started, the brake warning light came on. The front sensors have been changed so the warning lights don't come on when the knocking starts.

I am not mechanically minded but In my mind its a brake problem as the issue only shows up after driving for about 30 miles and things are starting to warm up.

The garage cannot identify the issue and have run out of ideas. Can anyone suggest or identify the problem as I have been replacing bits without success

Share this post


Link to post
Share on other sites

Remember that, just like the brakes, the shock absorbers also warming up by the friction on the in and out movements. The fact that the wheel sensors are replaced remind me of weak shock absorbers, the sensors go thereto defect. 

Share this post


Link to post
Share on other sites

Join the conversation

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

Guest
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 nightrn1
      I'm new to the Porsche family.... Just over a month and the proud owner of a 1999 Boxster.  It's a project car but still on the road and my point to point ride.  Must say, LOVE to drive this car....This one has  been lowered some, well alot... and does it hug the road..... Just doesn't miss much being that low....  My question is, I am having an issue with the rear lights on this car...  I know I had a problem with the left rear brake light.  I tried tracing back the wire but found no problem... I then switched the lamp holder from the right side to the left and all the lights worked... So I thought I had an equipment issue.  I bought a (Porsche) replacement bulb holder.  Came in last night.  Changed out today...Guess what????  Turn indicators work, Backup lights work,  Brake light works on the Right Side ONLY, (still) Now no rear tail lights what so ever......I have checked ALL the fuses, only had to replace one and it had nothing to do with the lights.  NOTHING has changed....Where did my tail lights go??????  Can't figure this out.......Please help.......Just FYI,  ALL the LIGHTS were working as of last Wed. when I did the bulb holder swap and checking the lights.  Power is to both wire harnesses.   Everything else works except the left brake light and the drive lights.  Go figure.......
    • By mrplow911
      The radiator grills on the 986 sit very low and thus tend to collect quite a bit of debris and garbage faster than other cars.  The design of the radiators and front air intakes is such a way that any debris which enters the grill get jammed between the radiator and the inside of the front bumper body panel.  
      Cleaning out your radiators and the garbage stuck behind the front bumper should be done periodically as leaving anything in there can cause inefficiencies to your cooling (A/C and engine) and also rust your radiators once the debris gets wet.  
      By adding mesh to the standard grill, using gutter guards for rain gutters, you can reduce the amount of debris which can enter your grill.  This is a simple process and adds not only functional value, but I think it looks pretty great too.  For me it took roughly 4 hours to access, clean the radiators and air intakes, and add the mesh to my front grills(not including painting the grills).
      Parts you'll need:
      •    Gutter Guard (this is the same stuff you use for rain gutters on a house to keep leaves and junk from building up in the gutter) - Buy two sheets of this.
      •    High gloss, black spray paint
      •    Tiny black zip ties - nothing too thick, but don't go too wimpy either.  You'll need about 4 zip ties.
      Tools you'll need:
      •    Torx set
      •    Vacuum
      •    Aluminum shears
      •    Wet rag and soap to wipe down the air intake duct which is likely dirty.
      I won't cover how to remove the front bumper, as that's available widely across Youtube, Renntech, and other DIY sites.  Here's the Youtube video I used (https://www.youtube.com/watch?time_continue=280&v=X2q54XtupVo).  
      So we'll get started with this tutorial once you have the front bumper cover removed.

      1.    The first step is to remove the grills which are held in place with 4 plastic tabs and pull out from the inside of the front bumper cover.  This is fairly straight forward – just be sure to follow the general rule of not trying to force anything!  Use the images below to help.


       
      From this image, you can see 4 plastic tabs are used to secure the grill in place, while 3 tabs on top are flat and just used to align the grill.
      2.    With the grills out, it’s time to trace them on paper so you can cut your mesh correctly.  I used a big sheet of painters drop paper, which I’ll later use when painting the grills, to trace around the whole perimeter of the grill piece.  It’s important to trace around the whole piece rather than just the vent portion, because the grill is rounded and so the mesh will need to bend in order to make this a tight fit.  If your mesh is too small debris will be able to make it past your grill.
      3.     Now it’s time to cut your gutter guard.  Using the metal shears, cut the mesh to match the outline you traced in step 2.  I found it easy to use a box knife to score and transfer the tracing from the paper to the gutter guard (since the gutter is painted, you just use the box knife to score the paint).

      Your cuts don’t need to be perfect.  Mine aren’t rounded, but you’ll see that they still create a great seal for stopping junk.
      4.    This next step is optional, though it makes a big difference in terms of looks!  I painted by grills.  There’s nothing fancy you need to do when painting them.  I applied three coats of paint just to ensure it was solid.  Let them dry for at least a day or two or else the paint will easily chip.   
      5.    The next step is to cut a whole out for the outside temp sensor which is sticks through the left grill (when looking at the car head on).  Before cutting the hole for the sensor, be sure to test out your mesh by holding it against and fitting it (bending it to form) with the respective grill it’s for.  
       This doesn’t need to be an exact science, and in this case it’s always better to cut less and test it rather than cut too much.
      I determined where the hole needed to be cut by holding the fitted mesh against the grill and scoring the part of the mesh which aligned with the hole on the grill.  I cut a small rectangle that is about a half inch, or in my case three snips of the mesh.  I probably couldn’t gone a bit smaller, but you can’t really notice. 
       

      6.    Next step is to adhere the mesh to the grill.  I did this a bit differently than others have since I didn’t’ want the mesh to be permanently attached to the grill.  I used small black zip ties which aren’t visible when viewing the car but hold the mesh securely in place and allow it to be replaced if they become damaged or a future owner doesn’t want them.  In the picture below you can see I used 4 zip ties for each grill.  Two on the very bottom which help support the mesh from sliding down, and two at the very top which help the mesh from being pushed back into the intake duct. 

      7.    The most difficult part of reassembly is aligning the outside temp sensor with the hole you made.  Prior to having mesh installed this was simple because you could just put your fingers in the grill and guide it.  There’s no trick to this, just take your time aligning it as you put the bumper panel back on.  It doesn’t need to be aligned perfectly since you can use needle nose pliers to adjust it after the bumper panel is in place. 
    • By mrplow911
      View this tutorial Radiator Grill Mesh and Painting
      The radiator grills on the 986 sit very low and thus tend to collect quite a bit of debris and garbage faster than other cars.  The design of the radiators and front air intakes is such a way that any debris which enters the grill get jammed between the radiator and the inside of the front bumper body panel.   Cleaning out your radiators and the garbage stuck behind the front bumper should be done periodically as leaving anything in there can cause inefficiencies to your cooling (A/C and engin Author mrplow911 Category Boxster (986) - Mods Submitted 03/23/2019 06:59 AM Updated 03/23/2019 07:46 AM  
    • By Julianjh
      Does anyone know how to disassemble the Lucas Master Cylinder installed on a 2002 996 C4
       
      I have removed the large circlip and the cotter pin, but can't get the piston out even with pulling.
       
      There is a plastic cover at the back of the cylinder which looks like it is a push fit, but this doesn't want to move and is quite brittle plastic so I don't want to break it. This could be threaded and therefore needs to be unscrewed to remove, but there are no lugs or holes which could be used with a tool to enable it to be turned.
       
      Grateful for any advice.
    • By Christiaan Poortman
      Hello, I'm new on this forum and stumbled upon a new problem (or old) with my 2.5l 986 Boxster from 1997.
       
      The problem occurs when the engine is started dead cold after sitting a few hours/overnight.
       
      Engine starts immediately but the RPMs start to surge / hunt between 1100 and 700 RPM. This continues for about 10 seconds after which the idle smoothes out to the normal cold idle RPM. 
       
      The first pull away requires a tad more throttle then normal to prevent stalling. After this first pull, everything is almost normal and engine performance becomes better and better. When the engine is hot, the idle sits at 780 RPM with a minor fluctuation now and then (seems to be more than normal)
       
      I've been to two shops (official Porsche dealer and local Porsche specialist). Porsche dealer couldn't find anything and the specialist found the camshaft sensor on the left bank to be unplugged - but now comes the strange thing - the cabling is nowhere to be found!!!!!!? Took the car home to check myself but didn't find anything.
       
      No camshaft related codes to be found in the diagnosis and no CEL either. 
       
      Attached one pic showing the sensor and it's missing plug
       
      Could someone help me out? - Is it possible for the engine not to throw a CEL when sensor is disconnected? - where is the sensor wire to be found?

×
×
  • 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.