Clicking / Tick noise in engine compartment

[valkyr]

Man, I hate to post this question as I'm probably going to get to be worried about all sorts of things.

Engine: 1988 454 7.4L V8
Drive: Bravo I

Background:
Replaced throttle/shifter recently. While engine was off, I shifted the controller several times HOWEVER boat seems to run out fine when on the water. During the rewire of the throttle I had a short circuit that caused everything to cut off. Didn't blow any fuses or anything AFAIK and fixed the short circuit and everything seems to work correctly.

Now:
When engine idling or "throttled up", with drive in neutral I hear this clicking noise near the back of the engine. I can't seem to locate exactly where it is, but its definitely louder in the back of the engine compartment. Kind of sounds like an exhaust flapper maybe or possibly a valve lifter (tho it wasn't doing that before I replaced the shifter). Could be coming from the shifter control box (? - not sure what thats called) on top of the engine (where the shift cable goes into from the shifter and then out to the drive).

My neighbor has engine muffs to amplify the sound with headphones so I'm going to try to use those to more accurately determine where the sound is coming from. Suggestions on best places to check?

Thoughts on what it might be?

 

[stevieray]

Re: Clicking / Tick noise in engine compartment

If it's a metallic "ping" - real quick & not at a regular interval, I'd say it's an exhaust flapper. Listen for it at the entrance to the Y pipe.

 

[Jsiples]

Re: Clicking / Tick noise in engine compartment

On that topic can these flappers be replaced if that is the issue without pulling the engine? I seem to have the same issue it is not consistent but is constant.

 

[Reel Poor]

Re: Clicking / Tick noise in engine compartment

jsiples, you should start your own thread to ask questions and also post the necessary information about YOUR engine so the question can be answered correctly. Serial number, engine size, and year.

 

[valkyr]

Re: Clicking / Tick noise in engine compartment

EGADS! Someone is trying to hijack my thread.....Help Help!!!

Just kidding.

I think maybe mine is the shfiter cable is slightly out of adjustment. Does backlash cause that clicking noise? If it is the shifter cable, is it a problem if its
"clicking"?

Thoughts? Ordered a shifter adjustment tool from iboats so I can make the adjustments but wonder if there's any harm being done if I use it in the meantime?

AND, when doing the shift cable adjustment does the engine need to be running or off??

Thanks!

 

[Jsiples]

Re: Clicking / Tick noise in engine compartment

My apologies

 

[stevieray]

Re: Clicking / Tick noise in engine compartment

Does it go in gear & out of gear OK? I don't think the cable itself would be making that noise (it just kind of sits there unless you're moving the shift lever).

 

[valkyr]

Re: Clicking / Tick noise in engine compartment

Yeah it goes in/out of gear fine. Read somewhere else that if its making noise in neutral its probably the shifter cable and since I have just recently done work on my shifter, I 'assume' thats what it is.

 

[valkyr]

Re: Clicking / Tick noise in engine compartment

Well I used the engine ear to identify the noise and its definitely coming from the exhaust area near where the exhaust "pipe" goes out the back of the boat.
Definitely sounds like an exhaust flapper....is this something to be worried about?

Thanks

 

[thrasher]

Re: Clicking / Tick noise in engine compartment

Some flapper valves (early Alpha 1's prior to 1995) have a rubber trim running around the edges of the flapper valve (to better seal the flapper valve and to stop the ratteling).
You have a bravo drive so I don't know if its the same flapper valve, later Alpha 1 models had 2 spring loaded flaps instead of an off center flap.
If yours is ratteling it probably means the rubber trim has worn through (or dropped off). The flapper will start to wear against the exhaust (metal to metal contact) but it will take a long time to do any real damage.
It is very easy to replace the flapper valve. You will need two new gaskets (they go between the exhaust manifold and the riser, 1 on each side), you remove the 4 bolts holding the riser to the manifold, you then loosen the jubilee clips holding the rubber boot to the top of the exhaust Y section and just pull the riser with the rubber boot upwards. It should all come off and expose the flapper valve in the top of the Y section. Reinstall as you removed, but use a new gasket for the riser/manifold joint. It took me 20 minutes a side to replace my flapper valves. Again this was all for an Alpha 1 drive not a bravo drive, I do not know what a bravo drive looks like, so this could all be useless information to you, but I am guessing they will be quite similar, so this should give a reasonable idea of whats involved.

Gary