#4 Cylinder intake valve stuck open |
|
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. |
|
#4 Cylinder intake valve stuck open |
gnomefabtech |
Mar 19 2023, 09:20 PM
Post
#1
|
Member Group: Members Posts: 97 Joined: 27-December 22 From: Los Angeles Member No.: 27,063 Region Association: None |
So I'm trying to resurrect this 76 (or is it a 75?) that I just bought and it doesn't have compression on the #4 (rear right) cylinder. After some tests with compressed air it's clear that the intake valve isn't closing. I pulled the valve cover and the rockers move OK but that valve does not close all the way. Everything else looks good.
I have a lift but was wondering if I could pull that head without dropping the engine. It looks like there is room but I'm not sure about the engine tin etc. Seems like either the valve is bent or somehow stuck and maybe I can just fix the one thing there. Anyone pull heads while the engine is still in the car? |
ClayPerrine |
Mar 20 2023, 11:21 AM
Post
#2
|
Life's been good to me so far..... Group: Admin Posts: 15,443 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille |
I know the original poster found his problem, but I wanted to add something that I saw on a 2.0 head.
The head was old enough that the valve seat started to recess into the head. Every time the valve closed, it hammered the seat deeper into the head. Eventually the valve stayed open. I readjusted the valve, thinking it was just too tight. It ran fine for about a week before the valve was too tight again. These are 50+ year old heads. At this point in time you are better off buying the new heads that are available rather than trying to use the ones you have. Just my $ .02. Clay |
Lo-Fi Version | Time is now: 9th May 2024 - 04:05 PM |
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 ... |