2001 Merc 454 7.4L Ticking/Knicking up top (sounds like)

[joebrown]

I have a 2001 with a 454 in it. I just purchased it at the beginning of July and last weekend noticed a light to meduim tick or knock on the top of the engine. The noise was not there the weekend prior and doesnt go away when the engine warms up, although its not as noticable when its throttled. I hear it mainly when in idle. Not really loud, just constant. Oil pressure is good, no loss of power, and its doesnt get louder with throttle. I was told its probably a loose lifter, but I dont know much about these things....

 

[ni7irs]

Re: 2001 Merc 454 7.4L Ticking/Knicking up top (sounds like)

I have the exact same noise. No oil consumption either. No noise at any speed other than idle. Was told its nothing. Don't know if that's right but its been there for two years.

 

[joebrown]

Re: 2001 Merc 454 7.4L Ticking/Knicking up top (sounds like)

I have the exact same noise. No oil consumption either. No noise at any speed other than idle. Was told its nothing. Don't know if that's right but its been there for two years.

If it was that way from the beginning I would believe it....but this just started...The boat seems to run just fine, but I cannot explain it. Just want some reassurance I guess.

 

[Volphin]

Re: 2001 Merc 454 7.4L Ticking/Knicking up top (sounds like)

Sometimes a little particle gets lodged in a pushrod or lifter that can cause a tick. Cams also wear over time and may require rocker adjustment. Try to use a stethoscope for mechanics (available at NAPA) to pinpoint where the noise is coming from... which bank and cylinder. Just lightly touch it to the valve cover and try different spots until the tick is loudest. And don't freak out. The normal sounds of a running engine can be slightly un nerving at first. Anyway, your tick will be easy to spot with that tool. Then take note if it is an intake or exhaust valve. Pull the valve cover and take a look. I've seen rockers come loose, or just need adjustment too. (+1/4 turn).

HTH

V

 

[Volphin]

Re: 2001 Merc 454 7.4L Ticking/Knicking up top (sounds like)

Oh, and if it is FI, are you sure you are not hearing the injectors firing? Just sayin...

V

 

[joebrown]

Re: 2001 Merc 454 7.4L Ticking/Knicking up top (sounds like)

The boat is FI...but thats not the sound its making. I looked at a few videos on You Tube and it sounds just like one video posted with loose flywheel bolts, but then again it also sounds like a loos lifter. Its not a deep knocking noise at all and I am not savy enough on engines to know the different sounds other than its knocking...or more like ticking. Really weird since it didnt do it two weeks ago and now all the sudden it started.

 

[boykster]

Re: 2001 Merc 454 7.4L Ticking/Knicking up top (sounds like)

Check the exhaust system too - it could be a shutter causing the ticking noise, especially if you only hear it at idle. I had a clacking noise for years on my 454 until I this season when I pulled apart the exhaust and replaced the shutters. They are located in the y-pipe downstream from your riser/elbows