Ticking noise coming from middle / rear of engine - Alfa Romeo Bulletin Board & Forums
 1Likes
  • 1 Post By ghnl
 
LinkBack Thread Tools Display Modes
post #1 of 14 (permalink) Old 06-04-2019, 06:38 AM Thread Starter
Registered User
 
Join Date: Jun 2018
Posts: 27
Question Ticking noise coming from middle / rear of engine

New to me 1750 spica '71 spider is making a ticking noise mostly at idle and maybe till about 2k but as the revs climb I don't hear it. I though it was an exhaust leak but I can't feel any air around the manifold or at the collector and don't see any soot. The car only has about 38k miles on it, not sure if this is enough mileage to consider needing to re-shim the valves but I have not measured clearances yet.

I read that if it was an exhaust leak it should get louder & persist as revs climb. The car drives fine otherwise and I know that spica being mechanical injection should be somewhat loud (i daily a 97 tdi so I know what mech injection sounds like) when firing the injectors but this noise is from the drivers side roughly middle or rear (towards firewall) of the engine.

Quick list of maintenance I did last fall:

fuel filter (at spica and inline at tank)
oil filter (engine and spica filter)
oil pressure sender(gauge tested fine)
airbox filters
diff oil
trans oil
engine oil 20w50


Here is a short video I took.

drive.google.com

/file/d/1iuY37qQG4fqn98TQLy8fQn-AeXVxGVbx/view?usp=drivesdk
AlexBassila is offline  
Sponsored Links
Advertisement
 
post #2 of 14 (permalink) Old 06-04-2019, 07:09 AM
BB Janitor
Platinum SubscriberSuper Moderator
 
ghnl's Avatar
 
Join Date: Oct 2005
Location: Mebane, NC
Posts: 16,113
Garage
My first thought was an exhaust leak, too. One way to locate it is to use a 2' - 3' length of 1/2" hose (like a piece of heater hose) as a stethoscope. It won't amplify the sound but you can safely aim one end at any suspect areas and listen at the other end.

It would certainly be a good time to check valve clearances.
sbadaro likes this.

- - Eric
don't read this
~ 1984 Spider Veloce ~
- -~ 1981 GTV-6 ~
Mebane, North Carolina


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
ghnl is offline  
post #3 of 14 (permalink) Old 06-04-2019, 07:50 AM
Registered User
 
spiderserie4's Avatar
 
Join Date: Jul 2011
Location: Cologne, Germany
Posts: 6,972
sounds typical alfa twin cam to me

exhaust #3 looks to be double nutted, if so why, a quik fix for a possible stripped stud perhaps?
In any case, certainly no harm in snugging up all those nuts.

have you adjusted the chain recently?

no harm also to at least check the valve gaps, as Eric says
(removing cam cover on your car is nice and easy compared to later spiders!)

Dom - Alfa Spider 1990 S4 - formerly: Alfa 101 Sprint, 2600 Sprint, Montreal - family classics: Jensen Interceptor II, '58 Hooper RR Silver Cloud I, Shadow II, '60 Corvette.
spiderserie4 is online now  
Sponsored Links
Advertisement
 
post #4 of 14 (permalink) Old 06-04-2019, 08:14 AM
Registered User
 
goats's Avatar
 
Join Date: Jul 2006
Location: san diego CA
Posts: 4,997
sounds like exhaust to me as well. That 1750 should not be making that much noise at idle.

74 GTV with 10548's and Ingram pump
71 Spider 1750 BOMBER ; 1995 LS 78K tight fast car
goats is offline  
post #5 of 14 (permalink) Old 06-04-2019, 08:23 AM Thread Starter
Registered User
 
Join Date: Jun 2018
Posts: 27
Quote:
Originally Posted by spiderserie4 View Post
sounds typical alfa twin cam to me

exhaust #3 looks to be double nutted, if so why, a quik fix for a possible stripped stud perhaps?
#3 is double nutted as a test a few min before taking that video. The stud looked a little chewed up right where the manifold meets it and the nut also loos a little chewed so I put another nut as a "spacer" to try and tighten the nut on some fresher threads. All other nuts are verified tight and sound didn't change when trying my nut spacer. I guess its still possible for #3 being a source of exhaust leak but I don't feel any air and the ticking essentially disappears somewhere above 2k (I stood half out of the car to rev while listening to the engine with hood up).
AlexBassila is offline  
post #6 of 14 (permalink) Old 06-04-2019, 08:48 AM
Registered User
 
Join Date: Apr 2006
Posts: 204
Ha, I have the exact same noise at #3 or #4 exhaust side! It started after an oil change and noticed after running the living daylights out of the car - which she normally enjoys.

Adjusted the timing chain as it seemed loose, measured the valve clearances and used a stethoscope to find if the noise was louder around the engine. Definitely coming from the exhaust side around #3 and #4, I think #4.

I did not check to see if the exhaust nuts were tight and will do so this weekend.

The clearances are as follows:
IN EX
1. .011" .014"
2. .012" .015'
3. .012" .014"
4. .012" .012"

I am not sure of the cams as I believe they are regrounds however RJ did provide valve clearances to use.

My old post is here: https://www.alfabb.com/bb/forums/eng...00-duetto.html

Plus I to have uploaded a short video of the engine noise and it is below.

https://drive.google.com/open?id=1Va...FhrSOTFqNiO9qS

Thoughts appreciated.

Chip
post #7 of 14 (permalink) Old 06-04-2019, 10:48 AM
Registered User
 
spiderserie4's Avatar
 
Join Date: Jul 2011
Location: Cologne, Germany
Posts: 6,972
Quote:
Originally Posted by AlexBassila View Post
#3 is double nutted as a test a few min before taking that video. The stud looked a little chewed up right where the manifold meets it and the nut also loos a little chewed so I put another nut as a "spacer" to try and tighten the nut on some fresher threads
ah ok, thanks, that explains that!

if nuts are all snug and no signs of carbon escape, then I'd say the flange is good.
what about the manifold itself, no slight crack a little lower down?
(though your 71 will have the good 2 piece manifold, less prone to cracking than the later USA one piece restrictive piece)

I'd still adjust timing chain, if you haven't done it on this new to you spider.
Our twin cams seem to transmit noise and it's hard to pin point the source. A loose chain can be noisy.

....maybe check the compression in cylinders to rule out anything odd there that might have happened after your italian tune up: all plugs out, hot engine, wide open throttle.
(edit) oh, sorry, it wasn't you who did this, it was shuga....got myself mixed up!

Dom - Alfa Spider 1990 S4 - formerly: Alfa 101 Sprint, 2600 Sprint, Montreal - family classics: Jensen Interceptor II, '58 Hooper RR Silver Cloud I, Shadow II, '60 Corvette.

Last edited by spiderserie4; 06-05-2019 at 01:00 AM.
spiderserie4 is online now  
post #8 of 14 (permalink) Old 06-04-2019, 11:59 AM
Registered User
 
Top Down's Avatar
 
Join Date: Aug 2016
Location: West Sussex UK
Posts: 157
I had an odd ticking (sort of) sound which took ages to locate, that turned out to be an air leak on cylinder #4 between manifold and head.

Daily drive is a Giulia 2.0 MA, wife drives a 939 Spider in the summer and a 1.6TS 147 in the winter. For special sunny days we have a S2 Spider Junior in the garage.
Top Down is offline  
post #9 of 14 (permalink) Old 06-04-2019, 01:39 PM
Registered User
 
VabeneGTV's Avatar
 
Join Date: Dec 2011
Location: Massachusetts
Posts: 1,164
Garage
loose plug(s)

Cars ruined my life! 😱
VabeneGTV is online now  
post #10 of 14 (permalink) Old 06-05-2019, 09:49 AM Thread Starter
Registered User
 
Join Date: Jun 2018
Posts: 27
Haven't checked for loose plugs yet but I will inspect that next as well as get the car up on stands and check the collector underneath for leaks as I am also hearing the same ticking noise under the car around the collector / front muffler section (its less pronounced but the sound is also present under the front of the car).

Something else I observed is that the ticking is approximately the same frequency as the bouncing of the tachometer at idle. Is it possible for the tach cable to make such a noise? I read another post where someone talked about the tach cable making noise when its needing to be lubricated.

Thanks for the input guys, I am hoping its just exhaust related, although the engine has low mileage I know the previous owner hardly did any maintenance (same air filter and pcv breather for the last 10+ years and spica filter was super slugged up), so it's not hard to imaging he might have not checked oil level or used incorrect oil etc.
AlexBassila is offline  
post #11 of 14 (permalink) Old 06-06-2019, 07:44 PM
Registered User
 
Join Date: May 2011
Posts: 31
I can’t open your video, so I will just ask. Is this a California car and if so, are you still running the air pump? The air exhaust rails are fragile and can spring leaks. Makes a loud ticking noise. Happened to me. You can replace the air rail or mend it with high temp epoxy
Mauricio101 is offline  
post #12 of 14 (permalink) Old 06-06-2019, 08:04 PM
Registered User
 
goats's Avatar
 
Join Date: Jul 2006
Location: san diego CA
Posts: 4,997
No air pump on 71

74 GTV with 10548's and Ingram pump
71 Spider 1750 BOMBER ; 1995 LS 78K tight fast car
goats is offline  
post #13 of 14 (permalink) Old 06-10-2019, 11:04 AM Thread Starter
Registered User
 
Join Date: Jun 2018
Posts: 27
Quote:
Originally Posted by Mauricio101 View Post
I canít open your video, so I will just ask. Is this a California car and if so, are you still running the air pump? The air exhaust rails are fragile and can spring leaks. Makes a loud ticking noise. Happened to me. You can replace the air rail or mend it with high temp epoxy
Not a cali car. Tach needle is bouncing at about the same speed / rate as the ticking noise. I checked spark plugs and they are all tight. The ticking noise doesn't get louder only faster as rpms increase. I read another post about tach cable making this type of noise, I'm not sure though as the cable runs to the water pump which is usually at the front of the engine.

I guess my next step is to pull the manifold and replace the 1 chewed up stud and replace the gaskets to see if that is the issue. I will also replace the collector gaskets at the same time.
AlexBassila is offline  
post #14 of 14 (permalink) Old 06-10-2019, 11:29 AM
PSk
Registered User
 
Join Date: May 2003
Location: Tauranga New Zealand
Posts: 11,293
Send a message via AIM to PSk Send a message via Yahoo to PSk
Does the tach cable require lubricating?
Pete

'71 1750 Series 2 GTV:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
156 Series 1 v6 ... and remember it's all just opinions
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
PSk is online now  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Alfa Romeo Bulletin Board & Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome