914 1.7 Knocking Sound -- New Here, First Post, Horrible knocking coming from the motor |
|
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. |
|
914 1.7 Knocking Sound -- New Here, First Post, Horrible knocking coming from the motor |
UberElectricEagle |
Sep 20 2009, 07:20 PM
Post
#1
|
atomic Group: Members Posts: 43 Joined: 10-August 09 Member No.: 10,659 Region Association: None |
Greetings. I am new to the Porsche world and I purchased a 1972 914 1.7 about a month ago. It's a pretty nice car over all, but I think the motor, or part of the motor, might be toast.
When I purchased it, it badly needed a muffler. The knocking noise was harder to notice and sounded more like an exhaust leak over the horrible sound of the lack of a working muffler. The car seemed to run decent even with the poor exhaust and the price was good so I bought it. I just wanted a decent car over all that I could drive around for fun on sunny days before the winter gets here. It came with stainless heat exchangers I installed and I installed a really nice dual muffler from Dave at Triad. When I fired it up with the new muffler, I really noticed the knocking when I drove it since the all the exhaust leaks were now sealed up and I wasn't wearing ear plugs. At idle it's not too bad, but once I get going, the knocking is very noticeable. It's odd too, because it's not real consistent under power in motion. To me it sounds like the noise is coming from the #1 cylinder. I think the cylinder is providing no power, because when I take the wire off the cap, there is really no change in performance. (I put a video link of the horrible sound below.) Any advice on where to go from here would be great. My gut feeling is telling me the motor is going to have to come out. If I'm going to do all that, I might as well put a 2.0 liter in or ????? I'd even settle for just a solid running motor with some minor upgrades to make it a little quicker. Any advice on what route to take on a good used motor would be great. I guess A motor that runs on 4 cylinders would be an upgrade. Thanks for your help, a mildly depressed Sam http://www.youtube.com/watch?v=a5JhEd7SUH4...re=channel_page |
ME733 |
Sep 22 2009, 09:07 AM
Post
#2
|
Senior Member Group: Members Posts: 842 Joined: 25-June 08 From: Atlanta Ga. Member No.: 9,209 Region Association: South East States |
(IMG:style_emoticons/default/popcorn[1].gif) First things FIRST....BASIC THINGS FIRST...."I pulled the wire out of the distributor cap....and there was no change". (in the dead cylinder). CHECK THE SPARK PLUG WIRE for continuity. (does electricy flow through it, and the spark plug connector , and connector that inserts into the CAP....= good or bad., bad = replace ALL of them. Good = go to spark plug next. remove and inspect, , oiled = missfiring, (can also have gas smell=misfiring). BAD = replace all spark plugs. be sure to gap them properly. Note ; there are replacement spark plug wire sets out there, that are of the suppression type. these are carbon impregnated, coated, (nylon, fabric, or some such). THEY are great for radio static suppression. BUT THEY will break internally. causes obviously, misfires or dead spark plugs. The noise may be from ..THAT particular Piston not being hot and ratteling in the cylinder. After these basic things well...Post.. what you do and discover. (IMG:style_emoticons/default/popcorn[1].gif)
|
Lo-Fi Version | Time is now: 10th June 2024 - 01:49 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 ... |