Sudden loud engine noise!!!, Help me diagnose.. but be gentle! |
|
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. |
|
Sudden loud engine noise!!!, Help me diagnose.. but be gentle! |
bondo |
Dec 3 2005, 07:27 PM
Post
#1
|
Practicing my perpendicular parking Group: Members Posts: 4,277 Joined: 19-April 03 From: Los Osos, CA Member No.: 587 Region Association: Central California |
Ok, I've got a 914, with an unknown engine (serial is for RoW 1.7) that was rebuilt "several years ago". Just now I was shuffling cars... started it up, backed it down the driveway. I let it warm up for a couple minutes and shut it off. Then I went to move the MG so I would have toom to park the 914 next to it. The 914 was off for maybe 5 minutes. When I went to start up the 914, it immediately had a loud clack/knock. I drove it up the driveway and parked it next to the MG, and it made the noise the whole way. (about 75 feet) I shut it off, went to get the camera to record some videos. Then I started it up, and recorded these videos:
First is idling at about 1400 RPM, for 30 seconds. Second is idling with a few blips of the throttle, also for 30 seconds. The videos are 2.7 megs each. Thanks! |
bondo |
Jan 7 2006, 05:15 PM
Post
#2
|
Practicing my perpendicular parking Group: Members Posts: 4,277 Joined: 19-April 03 From: Los Osos, CA Member No.: 587 Region Association: Central California |
Ok, I pulled a valve cover, and here is what I found...
The number 2 exhaust rocker has about 5 mm of clearance. Considering the circumstances, it seems unlikely that this is a dropped seat (happened with engine pretty cold). The tip of the valve also seems to be sitting at about the same height as the others, not lower.. so it looks like the pushrod side of the rocker isn't coming out far enough, not the valve side being stuck in. So now my thoughts are collapsed hydraulic lifter, or bent pushrod. Could anything else cause this? The rocker shaft is in place and tight, and the valve adjustment locknuts are tight. Keep in mind it happened suddenly. It looks like my next course of action is to pull the rocker shaft, pushrod tube, pushrod, and lifter.. does this sound right? |
Lo-Fi Version | Time is now: 16th June 2024 - 07:09 AM |
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 ... |