View Full Version : tapping noise maby knocking ?
camsdad Dec 5th, 01, 02:18 PM I have a 350cid with a problem and a hope ya all can help diagnosis.
It sounds lika a tapping noise to me.
When I first fire er up in the mornin, she seems ok. But afta a few minutes, here comes the tapping noise. I have checked the roller rockers, balls,and nuts, pushrods and even changed all the hydraulic lifters.
Seems like when the RPM reaches around 2200 rpm it pretty much go's away.
the noise is pretty dam loud at a lower RPM.
Various inputs have been, Piston hitting a spark plug, Piston slap ( what ever that is ) Bad lifters, bent push rods.
However she seems to run ok. Plenty of power and torque.
I did check the plugs and found 1 was darker than all the others. Like its burnning rich in that cylinder. Its hard to tell which cylinder it is.Seems like # 7. Im using
a 2ft wooden broom stick as a stethoscope.
It definately on the drivers side.
Im thinkin a bad cam ? But when I removed the lifters I checked them for wear and they all looked good.
Any other possible ideas ?
Thanks.
aradrs 69RS 350cid Turbo350 3:55 posi
JohnZ Dec 5th, 01, 03:46 PM Do you have headers? Header gasket leaks can sound just like "tapping" noises.
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JohnZ
'69 Z28 Fathom Green
camsdad Dec 5th, 01, 05:52 PM New Headders, New Edelbrock RPM heads.
New 2 1/2" exhaust and Flowmaster Delta Mufflers.
This problem started before the new add on's.
aradrs
novaderrik Dec 6th, 01, 07:39 PM a cracked flexplate will also make some strange noises.
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1971 Nova(looks like 69 camaro from underneath!)
355sb, vortec heads, HOT cam,T-10 tranny, 3.70 gears 16" IROC wheels
travis Dec 6th, 01, 11:40 PM A cracked flywheel can drive you nuts. Also, check for a sloppy distributor shaft. I have had those make annoying, unidentifiable ticking noises. A worn fuel pump can do this also.
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'78 chevy truck-355, 9.4-1, vortec heads, XE268, vortec rpm intake, 750 edelbrock, flowtech headers and terminators.
'77 Nova-slowly progressing project.
'78 Nova-parts car?
'95 Lumina 3.4L DOHC 210hp daily driver
Milan Dec 7th, 01, 05:54 AM Poss fuel pump? Take a long thin screw driver. Take the handle end and hold it to your ear. Place the tip on various points of the engine and hunt the loudest point down!
Just dont get it in any moving parts.
caribbean camaro Dec 7th, 01, 07:59 AM Trust me - recheck your exhaust manifold gaskets
I have gone through this - it may well have been blown before you changed them and after new install - it blows again !
I just did this over two weeks and each time I had to drop the entire y-pipe on my 3rd gen. to install the gasket !
Its a pain but it happens - recheck it again!
camsdad Dec 8th, 01, 08:32 PM Thanks for the additional help but like I had stated eairlier, its definitly on the drivers side of the block so I belive that eliminates the fuel pump. I have been there with the headder exhaust leak ticking noise before, sorry thats not it. The sound is more like a tapping or light knock.
aradrs
ZZ430DropTop67RS Dec 8th, 01, 08:43 PM Try pulling the plug wire on suspected cylinder.
Does noise change when load is removed?
A wrist pin noise would be reduced doing that test.
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Don~ ZZ430DropTop (http://hometown.aol.com/zz430droptop67rs)
~~~~and~~~~
Pro-Touring.com DropTop (http://pro-touring.com/featured_cars/Camaro/1967_Camaro/Don%20Seefeldt%2067%20Camaro/don_seefeldt.htm)
67 RS/SS Convertible, 70 RS/Z28
camsdad Dec 8th, 01, 09:56 PM Well I got under the hood again, Drivers side #7 cylinder, some plug fouling.
Engine seems to be going through a qt of oil every 1.5 to 2 tanks of gas. Im leaning toward piston oil ring and a poor cyl hone job or somthin in that cylinder. The guy at the machine shop who origionaly set this motor probably screwed me on the rebuild. The block Seem like she never realy was right from the get go. I herd that he ended up at the Co Jail soon afterward. Somthin to do with tweakin !
Arrgh !!!!
Anyways I currently have a 3970010 350 4-bolt main block at a local reputable machine shop. Shes sitting there 20 over and some rust in 2 cylinders. Hopfully it will bore out 30+ ok. However whoever built it up before used a screwed in the crank as a key. Bone-head !!
So Im leanin toward strokin-er !
Reusing my Edelbrock 70cc 2.02/1.60 heads. A Edelbrock RPM intake. My Rochester
carb,headders,and whatever else I can reuse.
Any suggestions out there on a reasonably priced crank kit, and Hydraulic Lifter camshaft.
ARADRS 69rs Currently, 350cid 2bolt main, standard TRW forged flat tops, Schneider 135-H cam, THD350, 3:55 Posi.
She's a daily commuter to and from work. Hop on the Hwy turnin 3200 to 4000rpm.
Thanks to all of you camaro enthusiast out there.
18436572 Dec 16th, 01, 07:37 AM When You tear down the old motor....post what You found wrong that was causing the problems....there were some good possibilities posted....gotta see Who wins the prize... http://www.camaros.net/forum/smile.gif
L e f t c o a s t Dec 24th, 01, 02:32 PM Tweakers never make good mechanics. I had one steal parts from me only to replace them with crap parts thinking I wouldn't notice...Methanphetamine is a nasty drug. I can't figure out why mechanics like to snort that **** .
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'67 Camaro Coupe 327
Edelbrock intake & carb, Dynomax headers and exhaust, cowl induction, TH350, Hotchkis suspension
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