knock

ok, here is how the story goes... i have a 91 navajo 113,000 miles i have been working on a rough idle issue for a while now replaced everything on it and decided to remove and clean the injectors. they were clogged up a bit. well i put everything back together ans had i knocking sound(sounds like tapping a screw driver on the intake) so i was told i might have dropped something in the intake so tore heads off. nothing in there and found a little scaring in number 2 piston but walls were good and everything moved good.installed new heads ,pushrods,plugs wires and changed oil.started it up it ran great took it for a drive and got about 3 miles ans the knock is back. baby it home and knock stopped then came back and is still here.it is running good but very loud knock and seems to change with rpms. took pass side valve cover off thats where its coming from and rockers and rods are tight and good.i am at a complete loss here.checked plugs motorcraft plat and have yellow spark coil checked within specs and injector seems to be working . please can someone help i have alot invested in this . thanks for reading ...... chad

Chad,
Are you sure it's not a timing issue? If the motor "Clatters" under load, you may just have to advance (+/-) timing. More detail would yield more response! How is it knocking/sure it's a knock? Can you get a video?

I will get a video when i get home from work . I dont think its timing issue.dont think you can adjust timing on it . it does it at idle and gets louder with rpms. I unpluged spark plugs one at a time on that side and nothing changed with knock . when i had it apart lifters and all looked good . Was wondering if leaking injector could do this read some about that . But not sure .
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video

well here is the vid hope it helps:roll: <embed width="600" height="361" type="application/x-shockwave-flash" allowFullscreen="true" allowNetworking="all" wmode="transparent" src="http://static.photobucket.com/player.swf" flashvars="file=http%3A%2F%2Fvid763.photobucket.com%2Falbums%2Fxx280%2Fchadreinhard%2Fnavajo%2520knocking%2FSDV_0067.mp4">


not sure how to add vid hope this works

Chad,
I believe you have to upload to youtube/photobucket and then past the link with the link tool above the response/dialogue box.

got the video figured out

heres the vid hope it helps. again this all started right after reinstalling the injectors
http://www.youtube.com/watch?v=fuHH90KIaSY

It might be coincidental that it started after new injectors, but that is a rod knock.

Sorry.

I took off valve covers and everything is was tight and looked good .
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If it where a valve train issue it would not sound as "deep" as that. Valve trane / push-rods etc will have a more clatter, clicking, or ticking sound. The sound in your video unfortunately is a lower end rod knock. It has nothing to do with the valve train. The onlt thing you can do now is look into getting a different motor in there or drive it till it dies. My neighbor drove his 86 mercury sable for 3 years witha rod knock with no issues - just knocking is all.

It sounds to me like you might have a piece of carbon bouncing around in there. I have seen this before, one time I changed a set of plugs and it sounded like a bad rod knock! A little water down the carb and the noise was gone! You may want to try some upper combustion chamber cleaner. Or you can use the water trick, take off the vacuum line to the brake booster start up the engine let it get warm, run at 2000 RPM put the hose under water let it suck up a little at a time if it is carbon it will clear up. It is worth a shot!

Good Luck

Well got it in the shop my guys said if no damage since i never drove it with knock they will replace bearings for around 100 bucks . So hope to have it back this week
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Well it was not a rod but a bad coil causing a miss fire . The navajo is all good and running like a dream . Now onto the next project . Thanks everyone .
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Hi, this is EXACTLY what happened to me!!!yep, did some testing and cleaning of some injectors. Replaced 2 of them. Put it all back together and heard this same noise!!
Thought maybe an injector cap fell down in to the valve. Pulled off valve cover to look. Just didnt seem right that the noise started right after the injectors. Sure sounds just like a rod knock .!