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)

Cylinder misfire, gasket blown inside bore


Recommended Posts

Those Durametric numbers look fine. However, if the DME has been reset recently, 10 min may not be enough to get a steady state values. The best is to drive the car for a while say half a day then re-measure everything. Also the MAF reading of 20 kg/hr sounds high at 700 rpm. I think it should be around 15-18kg/hr.

After I got to op temp, MAF sticks between 17.8 to 18.6 on 700RPMs.

Link to comment
Share on other sites

You should be able to pinpoint the location of the noise better if you use a long screwdriver or a stethoscope with a metal rod attached at the business end. Just poke around the bank 2 cam cover and see if you can pinpoint the noise to a cylinder. I would monitor the misfire counters on all cylinder during the test drive.

It may be just a bled down lifter.

  • Upvote 1
Link to comment
Share on other sites

Those Durametric numbers look fine. However, if the DME has been reset recently, 10 min may not be enough to get a steady state values. The best is to drive the car for a while say half a day then re-measure everything. Also the MAF reading of 20 kg/hr sounds high at 700 rpm. I think it should be around 15-18kg/hr.

After I got to op temp, MAF sticks between 17.8 to 18.6 on 700RPMs.

Makes sense. I missed that you said the yellow rolls are when the engine was just started.
Link to comment
Share on other sites

Gentlemen, we are go! :thumbup:

Made some adjustments and started my engine again. Everything worked beautifully right from the start, knock was completely gone. Took a nice short test drive. Leak down test 100 / 95+ PSI per each cylinder and I did not even trouble to find TDC exactly which is important to get best values. Engine sound really good and identical for both banks. Durametric values looked good. Poking upper and lower head parts with stethoscope produced smooth sounds, just like it should.

I did the following since my last run:

1. retightened my exhaust parts

- I do not believe knock was caused by this. However, my cats were quite loose from the chassis and these vibrated quite a bit last time

2. Added more oil

- last time after I shut down my engine, I was on the lower end of my stick, only one bar on cockpit

Last time even my bank 1 knocked just a bit, now both banks sound smooth. I believe that my camshaft parts simply did not get enough oil.

In any case, all this cleaning job produced good results. After each cleanup, engine sounded always better. Too bad that my previous run was plagued by low oil volume.

What a way to start 5 week summer vacation :cheers:

Link to comment
Share on other sites

  • Moderators

Gentlemen, we are go! :thumbup:

Made some adjustments and started my engine again. Everything worked beautifully right from the start, knock was completely gone. Took a nice short test drive. Leak down test 100 / 95+ PSI per each cylinder and I did not even trouble to find TDC exactly which is important to get best values. Engine sound really good and identical for both banks. Durametric values looked good. Poking upper and lower head parts with stethoscope produced smooth sounds, just like it should.

I did the following since my last run:

1. retightened my exhaust parts

- I do not believe knock was caused by this. However, my cats were quite loose from the chassis and these vibrated quite a bit last time

2. Added more oil

- last time after I shut down my engine, I was on the lower end of my stick, only one bar on cockpit

Last time even my bank 1 knocked just a bit, now both banks sound smooth. I believe that my camshaft parts simply did not get enough oil.

In any case, all this cleaning job produced good results. After each cleanup, engine sounded always better. Too bad that my previous run was plagued by low oil volume.

What a way to start 5 week summer vacation :cheers:

Glad to hear it is finally coming together for you! :thumbup:

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • 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.