Reply
 
Thread Tools Search this Thread Display Modes
 
Old 08-25-2017, 05:12 PM   #1
Lt. Commander
 
jrsick's Avatar
 
Join Date: Oct 2011
Location: Chesapeake, VA
Posts: 139
Default Engine has a tick

2006 5.0 I/O with carburetor. I've got a distinct ticking noise coming from area under the valve cover on the port side. Sound is aft, from cylinders 5 or 7.
I need advice to ensure I check this out the correct way. I thought I would first check the lead wires for jumping sparks, then check that spark plugs are secure.
Then, do you think it would be good idea to add engine treatment to the oil and see if that would help, perhaps free some sticky lifter?
If no luck at that point, I would remove valve cover and check for loose rods.
Your recommendations, advice, or questions are most welcome.
Randy
__________________

jrsick is offline   Reply With Quote
Old 08-25-2017, 09:18 PM   #2
Admiral
 
mmwjr's Avatar
 
Join Date: Feb 2012
Location: Perry Hall, Maryland
Posts: 5,394
Default

Most likely a lifter or too much valve train clearance.

Try removing the suspected cylinder spark plug wires one cylinder at a time to see if the noise changes. If it does you know which cylinder has the issue.

You can try the treatment. A warm valve stem, colpased lifter, or the rocker stud could have pulled out some as they are pressed in.
__________________

__________________
Mike
mmwjr is offline   Reply With Quote
Old 08-25-2017, 09:42 PM   #3
Commander
 
Join Date: Sep 2015
Location: Chesapeake, VA
Posts: 422
Default

Should be easy enough to pull the valve cover and feel the rockers for each valve while it's closed.
speedysprocket is offline   Reply With Quote
Old 08-25-2017, 10:02 PM   #4
Admiral
 
mmwjr's Avatar
 
Join Date: Feb 2012
Location: Perry Hall, Maryland
Posts: 5,394
Default

Forgot to mention a tick could also be an exhaust leak.

Manifold to cylinder head.
__________________
Mike
mmwjr is offline   Reply With Quote
Old 08-26-2017, 01:09 AM   #5
Lt. Commander
 
jrsick's Avatar
 
Join Date: Oct 2011
Location: Chesapeake, VA
Posts: 139
Default

Thank you Mike and Speedy.
For the lifter/rocker recommendations, should my first step be to look at the rockers and see if there is a rod with play or a nut that is backed off? I have some understanding of rockers and rods, but have never adjusted lash myself.
For exhaust leak, how do I check for that? I have a stethoscope, but not sure where to check.
Speedy, what part of Chesapeake are you in? I'm in Great Bridge. My boat is in OBX though so I have to plan out all the tools I need before driving down.

Randy
jrsick is offline   Reply With Quote
Old 08-26-2017, 04:08 AM   #6
Admiral
 
mmwjr's Avatar
 
Join Date: Feb 2012
Location: Perry Hall, Maryland
Posts: 5,394
Default

There is no lash adjustment on this engine. One torques the rocker to spec the the valve is in the closed position, see manual for details.

If you pull the valve cover you can check the push rods for play but the valve must be in the closed position for each one which means you'll need to rotate the crank. To make this easier remove the spark plugs to remove compression. There is risk that is low you can break the bolt on the balancer when turning the engine however if you turn it counter clockwise the bolt should unscrew instead of break if the rotating resistance is to high. Again removing the spark plugs will make this much easier.

SBC exhaust manifold has little gap to the head, use a tissue and hold it laid out around each port to the head if there is a leak the tissue will wave like a flag.
__________________
Mike
mmwjr is offline   Reply With Quote
Old 08-26-2017, 11:22 AM   #7
Commander
 
Join Date: Sep 2015
Location: Chesapeake, VA
Posts: 422
Default

There may be a kit to make the rockers adjustable, but if you need that, something is wrong and needs to be replaced. I only did that on my 7.4 because they surfaced both the block and heads and I thought it might be too much.
I live in Great Bridge, too. Off Cedar Rd. Boat is at NOB marina.
speedysprocket is offline   Reply With Quote
Old 08-26-2017, 12:40 PM   #8
Lt. Commander
 
jrsick's Avatar
 
Join Date: Oct 2011
Location: Chesapeake, VA
Posts: 139
Default

I appreciate your inputs.
I will dive into SELOC and start work on Sunday morning. Let me know if there is a better manual than SELOC.
jrsick is offline   Reply With Quote
Old 08-26-2017, 02:40 PM   #9
Admiral
 
mmwjr's Avatar
 
Join Date: Feb 2012
Location: Perry Hall, Maryland
Posts: 5,394
Default

Quote:
Originally Posted by jrsick View Post
I appreciate your inputs.
I will dive into SELOC and start work on Sunday morning. Let me know if there is a better manual than SELOC.
There is its the mercruiser manual which can be found under Documents of this site.
__________________
Mike
mmwjr is offline   Reply With Quote
Old 08-26-2017, 05:18 PM   #10
Lt. Commander
 
jrsick's Avatar
 
Join Date: Oct 2011
Location: Chesapeake, VA
Posts: 139
Default

Mike,
I saw the documents, but looked to me like they were dated 1999. I wasn't sure if info was same for my 2006.
I downloaded the Mercruiser manual and read section on valves. It says valve lash is one turn down from zero lash. But you have info that says torque from zero lash. Do you think both are same torque levels?
__________________

jrsick is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not 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


Powered by vBadvanced CMPS v3.2.3

All times are GMT. The time now is 01:29 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.