Return to tapping

[emeraldlion333]

Ok, now, I've listed on this tap before, but haven't found the cause yet, and have some more details. I work witht the hospital so I rigged up a stehy with a scredriver stuck in the end of the stethoscope and couldn't really locate a specific origin as far as the engine went(I didn't crawl underneath and listen to the trans or diff. The tapping is worse when temps are cold, and occurs at idle and at low speeds >5mph.
The nose become less sever and sometimes stops altogether when I put in in drive and begin to drive but if stopped at a light it will sometimes faintly return. When the engine warms it's less obtrusive especially in drive, but when you stop and put it in park or neutral, it will return. I'd like to get this ironed out so I can focus on the bad bearing sort of noise/rattle coming from my transhump area(I have a feeling that is the transfer case chain needing replaced). Want to get the tapping gone first. Engine was rebuilt 1500 miles/15 months ago

[jaber]

I dont know if it helps any but I pulled the valve coves off and found a bent push rod. just wiggled the rackers to find it. It reminded me of what your discribing and is simple and easy to check and rule out. Just my .02.

[1BDWAGN]

I had horrible tapping like noise. Worse when cold then went away as the vehicle warmed up. I replaced the exhaust manifold gaskets and that got 95% of that noise taken care of. Now the heat riser valve on the pass. side makes a light puff-puff sound as exhaust is escaping near the shaft the valve rotates on. I'll cut it out and weld it up one day. I also have a noisy catalytic converter and need to weld the connection from the cat to the muffler. Those are some places to look.
Also the PCV valve can be noisy. The particular brand I bought seems noisy and it is most noticable at idle.

[Gambler68]

I have a horrid tapping noise in my AMC 327..my mech.(who I bought the truck off of) explained to me that it was a rod with a roller on it..it will tap but wont "get worse" for another 50-100k (the engine has 220k). I've tried some Marvel Mystery oil and see if that helps..

[carrotman]

It's hard to help unless you know exactly where the noise is coming from. You can manually close the exhaust heat riser with a wrench and see if the noise changes. You can listen with your stethoscope to the valve cover and see if the noise is in there.

[AMX factor]

Could be the thrust bearing on the crankshaft. Mine has a low rpm tap. Thrust bearing is my problem.

[89grand]

Maybe you have a partially restricted oil passage. I had a tapping noise too a few years ago, and I didn't do anything about it. Then one day I was forced to look into it because my Grand started running awful and the tapping got real loud. I pulled the passenger side valve cover off and to my horror, the pushrod had gone right through the rocker arm. I put new rocker arms and pushrods in the passenger side and then I had a loud squeaking noise. Diagnosis: restricted oil passage at that particular rocker arm. Cure: motor flush then changing the oil. The Grand has been good for year and a half since.

[ March 07, 2004, 12:22 PM: Message edited by: 89grand ]