Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG. This site is not affiliated with Porsche in any way.
Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners.
 

Welcome Guest ( Log In | Register )

 
 Reply to this topicStart new topic
> 912e mild backfire on deceleration
rosenfe
post Dec 7 2014, 06:19 PM
Post #1


Senior Member
***

Group: Members
Posts: 549
Joined: 14-October 13
From: northern california
Member No.: 16,512
Region Association: None
when i accelerate and take foot off gas ,i get backfire sound -or similar to that.its not loud,but noticeable.any ideas of what to check.these cars have backfire valve,but im not sure how that works.car runs strong,just adjusted valves.someone on 912e forum suggested exhaust system gaskets,but im not sure if they were referring to gasket at headers or muffler.any ideas?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
rick 918-S
post Dec 7 2014, 06:29 PM
Post #2


Hey nice rack! -Celette
***************

Group: Members
Posts: 20,456
Joined: 30-December 02
From: Now in Superior WI
Member No.: 43
Region Association: Northstar Region
Is it back firing or popping from an exhaust leak?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Mikey914
post Dec 7 2014, 06:30 PM
Post #3


The rubber man
**********

Group: Members
Posts: 12,661
Joined: 27-December 04
From: Hillsboro, OR
Member No.: 3,348
Region Association: None
Exhaust leak
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
rosenfe
post Dec 7 2014, 06:41 PM
Post #4


Senior Member
***

Group: Members
Posts: 549
Joined: 14-October 13
From: northern california
Member No.: 16,512
Region Association: None
well the responses suggest exhaust leak.any suggestions as to how to find it?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
rosenfe
post Dec 7 2014, 06:44 PM
Post #5


Senior Member
***

Group: Members
Posts: 549
Joined: 14-October 13
From: northern california
Member No.: 16,512
Region Association: None
more of a popping sound,can i continue to drive it until i find leak or can i burn a valve etc
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
pisces914
post Dec 7 2014, 07:01 PM
Post #6


Member
**

Group: Members
Posts: 62
Joined: 27-April 04
From: seattle, wa
Member No.: 1,988
QUOTE(rosenfe @ Dec 7 2014, 04:41 PM) *

well the responses suggest exhaust leak.any suggestions as to how to find it?


take a look at all of the connection points/gaskets - then look at the muffler itself for any holes, especially if you see seams and welds

hope this helps

brad
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
patssle
post Dec 7 2014, 07:19 PM
Post #7


Senior Member
***

Group: Members
Posts: 981
Joined: 28-August 09
From: Houston, TX
Member No.: 10,741
Region Association: None
Look for carbon blowout - any darkened areas around gaskets and such.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
roblav1
post Dec 7 2014, 07:49 PM
Post #8


Senior Member
***

Group: Members
Posts: 528
Joined: 18-September 12
From: KY
Member No.: 14,943
Region Association: MidAtlantic Region
Yup... exhaust leak.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
dknechtly
post Dec 8 2014, 09:29 AM
Post #9


Yellow 914
**

Group: Members
Posts: 68
Joined: 11-April 03
From: Wylie, TX
Member No.: 560
Region Association: None
If you have a two nipple vacuum advance, check that it is good. One of them helps pull back on deceleration.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
stownsen914
post Dec 8 2014, 10:45 AM
Post #10


Senior Member
***

Group: Members
Posts: 913
Joined: 3-October 06
From: Ossining, NY
Member No.: 6,985
Region Association: None
Or you already have a burned valve (or not seating properly). The exact symptom I had years ago on my 914 2.0. When I pulled it apart there was a burned valve ...

Check the exhaust leaks first obviously since that's external. You'll hear different methods for doing this, but my favorite is probing around with a length of fuel hose (or other similar sized hose), one end near (but not too near!) your ear, and the other probing around where you think there may be leaks. You'll hear a very audible poofing sound through the hose when you get near a leak.

Scott
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
rosenfe
post Dec 8 2014, 11:53 AM
Post #11


Senior Member
***

Group: Members
Posts: 549
Joined: 14-October 13
From: northern california
Member No.: 16,512
Region Association: None
noise had gotten louder after adjusting valves.they were definitely tight.im hoping for exhaust leak.heads were recently doen.i dont want to think about burned valve.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
rosenfe
post Dec 8 2014, 12:43 PM
Post #12


Senior Member
***

Group: Members
Posts: 549
Joined: 14-October 13
From: northern california
Member No.: 16,512
Region Association: None
would a bad deceleration valve cause this problem?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
« Next Oldest · 914World Garage · Next Newest »
 

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 

Display Mode: Standard · Switch to: Linear+ · Switch to: Outline

Track this topic · Email this topic · Print this topic · Subscribe to this forum

- Lo-Fi Version Time is now: 15th May 2024 - 12:40 AM
Invision Power Board v9.1.4 © 2024  IPS, Inc.
All rights reserved 914World.com © since 2002
914World.com is the fastest growing online 914 community!
We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ...