Engine Noise

Hg80Design · Aug 19, 2009

Hello, I recently fired my mustang and noticed I now have a knocking noise coming from the engine. I was wondering if anyone on here can help me identify it. Engine work is not my strongest suit and I am on a learning curve here. Any help would be greatly appreciated.

I have uploaded a video of the noise to youtube and can be reached at this link:
YouTube - Engine Noise 302 Mustang

or the video can be downloaded here:
Index of /engine (just click on sound.AVI to open)

I figured this would be easier and more accurate than me trying to describe the noise. Sound can be heard very clearly from about 13 seconds on.

Thanks for your help.

6Stang7 · Aug 19, 2009

Sounds like it might be a rod bearing, but there are other possibilities.
How many miles are on the motor?

Hg80Design · Aug 19, 2009

Motor was rebuilt about 4 or 5 years ago. So there should be less than 10,000 miles. But the mechanic I used was...not the most wonderful, so I have my doubts he did what he claimed. Most everything else he did I have either replaced or fixed on my own.

engarom · Aug 19, 2009

Have you tried

Takeing the valve cover off and checking your rockers?
if they are out of adjustment or loose you can get that sound.
You may even find one just flapping around in there.

Hg80Design · Aug 19, 2009

I will check that, I also replaced the header gasket and the noise is persisting.

1992MustangGT · Aug 20, 2009

Just listened to the video and it sounds like a bad lifter or loose rocker arm to me. A knocking sound from the crank would have a deeper, more solid "knocking" or "clunking" noise. The sound I'm hearing from your video is more of a "ticking" noise rather than a knocking, which indicates bad lifters or loose rocker arms. Hope this helps....

jcode68 · Aug 20, 2009

Seems to be a lot of new "engine noise" threads in the last week. Be sure you do not have any exhaust leaks besides just the headers. On some heads, there are thermactor or smog ports that should be sealed. If the screw in seal is leaking or missing altogether, it will make the sound in your video and make you think it is valvetrain related. I chased a similar noise in my 347 for months, adjusted roller rockers 3 different times and still sound was there. I happened to check all around the heads (not just at headers) for exhaust leak and found on my AFR heads there is a thermactor port on the back which had come loose and was missing. Easy fix, but lots of effort to find.

Hg80Design · Aug 20, 2009

Okay I popped the valve covers off today. And some of my pushrods spin freely by hand. I would say that I can spin at least half of them with ease by hand. There seems to be no up and down play though. I went ahead and started the car with the covers off and noticed that one of the pushrods is spinning almost continuously as the rocker moves up and down. Could this be the culprit and if it is how do I fix it? I have 78 heads with pedestal mount rockers.

Hg80Design · Aug 20, 2009

If video if this would help just let me know.

Hg80Design · Aug 22, 2009

So I removed the rockers and checked that each pushrod is straight. Reintalled each rocker, and started the engine. I Now have even loader clatter in that I think the rockers were installed wrong.

Can anyone tell me the proper procedure for installing and adjusting pedestal rockers on a 78' 302. The method I used was:

Make sure both valves are closed on cylinder 1 by watching for the intake valve to close. Tighten both intake and exhaust rockers down to 25lbs.

Next rotate the engine 1/4 turn and proceed to the next cylinder in the firing order. repeat for each cylinder.

1-5-4-2-6-3-7-8 is the firing order I used. Can anyone tell me where I went wrong?

jcode68 · Aug 22, 2009

Here is a 1 pager from Crane on installing/adjusting pedestal mount rockers for 77 & up SBF. Take a deep breath and start from the begining to ensure each step is done properly. Sounds like you may not have had the cam lobe in the correct position when you adjusted them. Also pay attention to the instructions regarding possible need for shims. Good luck and report back your results.

coppershim · Aug 28, 2009

Hi
.
check this...

the way to set correct valve lash, which is for hydraulic lifters zero lash do the following!

See the link i posted...
As you van see on it, the pulley gives three positions. These correspond with the 1,2,3 pictures on the right. Above it you can see for which engine (221, 255, 260, 289 etc)

Each valve must have ZERO lash. Tighten the rocker for each valve which is BLACK so that the rocker cannot move and is tight on top of the valve. Do this by gently tightening the rocker with one hand, and feel with you other hand when it tight.When you have this, turn the screw 1/2 to 3/4 more tight.
This way you have the lifter pushed down. Do this with al the valves according to the drawing.

When your done, you should have correct valve lash and the sound should be gone.

If you here a knuckling or hammering sort of sounds, than maybe one or 2 of your lifters is clogged up.

For this, see this link:
http://autorepair.about.com/library/a/1g/bl865g.htm

Engine Noise

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