Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > 911 Engine Rebuilding Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Nux Nux is offline
Registered User
 
Nux's Avatar
 
Join Date: Mar 2016
Location: Copenhagen, Denmark
Posts: 369
Garage
Help me identify this engine sound

This is a '89 3.2:

https://www.youtube.com/edit?o=U&video_id=kboKTcM3KH4

It gets worse when the engine is hot. Disappears over 3000rpm. Sometimes it switches over to a "angry cat rattle" sound (hard to describe). It's quite loud and does not sound good at all!

I first thought it was chain tensioner noise. I have checked both sides and both are good. I can depress the chain a little with my fingers on the right side though. I changed the left side tensioner just because I though the noise came from here - no change. Ramps look good too.

Did the fan belt test, and the sound disappeared.....I thought. Changed bearings and checked the alternator. All is good. Fan does not hit anything. Did get the "angry cat rattle" while the belt was off, so not that.

Pulled all the valve covers. No issues. No broken studs. Rockers and arms are good, and valve springs look ok by the first look (did not test them yet)

I don't think it's an exhaust leak.

I'm beginning to suspect some more serious stuff. Rods etc. What do you think?

Last edited by Nux; 03-13-2018 at 01:37 PM..
Old 03-13-2018, 01:34 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered User
 
'76 911S 3.0's Avatar
 
Join Date: Aug 2004
Posts: 815
Garage
Your video link is not correct, links to uploaded videos on my own account.
__________________
-Jayson
1976 911S Signature Edition - 3.2SSt (JE 98mm 9.5:1 pistons, 964 Cams, ARP Rod Bolts, Big Port SC Heads, 3.2 Carrera Manifold, ID725's, B&B Headers, TS HyperGate45 Gen V, TS RacePort, BW S360, AEM Infinity 506, E85)
IG: Signature_911
Old 03-13-2018, 03:05 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Under the radar
 
Trackrash's Avatar
 
Join Date: May 2007
Location: Sebastopol, the land of wine and redwoods in The Republic of California.
Posts: 4,897
Garage
These stethoscopes are available at HF for a small investment. Worthwhile to locate a noise.
__________________
Gordon
___________________________________
'71 911 Coupe 3,0L outlawed
#56 PCA Redwood Region, GGR, NASA, Speed SF
Trackrash's Garage :: My Garage
Old 03-13-2018, 08:14 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Nux Nux is offline
Registered User
 
Nux's Avatar
 
Join Date: Mar 2016
Location: Copenhagen, Denmark
Posts: 369
Garage
here's the correct link:

https://youtu.be/kboKTcM3KH4
Old 03-13-2018, 09:42 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Nux Nux is offline
Registered User
 
Nux's Avatar
 
Join Date: Mar 2016
Location: Copenhagen, Denmark
Posts: 369
Garage
also: Should I be able to easily depress the cam chain with my fingers (with the tensioner installed)? The tensioner does not buttom out. But maybe it doesn't build oil pressure and thus only uses the built in spring load?

On my other car (a 3.0) both chains were very tight, nothing like this.
Old 03-13-2018, 11:33 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered Minimalist
 
75 911s's Avatar
 
Join Date: Aug 2015
Location: Las Vegas
Posts: 1,744
Garage
No. The tensioners are very difficult to depress, even using the chain as a leverage or a coin (over the piston while the tensioner is out of the car). You need a vise basically to depress them when they are correct. I recall a thread on priming the carrera style tensioners properly.

I completely disassembled my 3.2 a few months ago. If I remember, the chains were rock solid in there. In my 2.7 there is a tiny bit of slack.

That doesn't sound good at all. You are pointing the camera at the left side in the video, is that where the sound is coming from?

IMHO Clean off all that blue RTV, flatten the covers by sanding them on a glass pane, and use loctite 574 if anything when you put them back together.
__________________
Duane

http://forums.pelicanparts.com/porsche-911-technical-forum/878569-born-75-me-my-new-911s.html

Last edited by 75 911s; 03-14-2018 at 05:54 AM..
Old 03-14-2018, 05:50 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Nux Nux is offline
Registered User
 
Nux's Avatar
 
Join Date: Mar 2016
Location: Copenhagen, Denmark
Posts: 369
Garage
well......I'm a little embarrassed:

It turned out to be the fresh air blower!! I was 2 sek away from dropping the engine hahaha

At least I checked that chains, tensioners, valves and springs and cams are all good. And my alternator has new bearings as well. On the road again
Old 03-15-2018, 03:34 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
Join Date: Dec 2007
Location: Just a little north of 13669/Nation's capital
Posts: 867
Send a message via AIM to brighton911
Happy and much cheaper ending. No need to be embarrassed, just about everyone has had such misstep. And it adds to your (and ours) knowledge base.
__________________
1986 Targa Guards Red
2012 Cayman S
Old 03-15-2018, 10:59 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 02:19 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.