Tapping noise when cold, 200 I6

[Anonymous]

Hey All,

I had an exhaust leak out of my manifold for a good while and I just got new headers installed so for the first time in a long time I have a pretty quiet car. Now I can hear a definite, rhythmic tapping when the engine is cold. Once the engine is warm it goes away. I know this is vague, but are there any usual culprits that I should check for?

Thanks for any help

-Dan in Atlanta

 

[Anonymous]

Sounds like lifter noise. Oil passages into the lifters are partially blocked and as the oil warms up it gets thinner and can enter the lifter easier.

 

[Anonymous]

comet I have the same problem except my noise is kinda loud clicking and it doesnt go away when its warm

 

[Anonymous]

comet I have the same problem except my noise is kinda loud clicking and it doesnt go away when its warm

That might be that your rocker arms are out of adjustment or your lifters are too worn to hold oil.

 

[Anonymous]

The noise does follow the RPM of the engine so a lifter sounds right. Do I need to do something about the lifters if that is what is causing the noise? How would I pinpoint which lifter is causing the noise? What damage can this cause? Thanks again for any help.

-Dan in Atlanta

 

[Anonymous]

dan there very easy to to replace and there not that expensive even for performance ones its worth it if you have the time.. mine are so LOUD on the ranger 2.9l efi 4speed auto... extremely loud and they follow as the rpms go up but I dont wanna change those because the trucks crap... my grand father used to pressure clean with it and carried this 55gallon jug of chlorine and oh my did it drip all in the crack where the bed and cab is and all down the back of liner down to the frame down to the brake lines.. so bad the hole tailgate is eaten away the rear bumper just fell off and its just terrible=) no where to even weld another one on unless I get long enuff metal to go all the way to the middle of the frame:|

 

[MustangSix]

On a high mileage engine it might be piston slap. As the bores wear the piston clearnce increases allowing the piston to wobble around in the bore. This makes a kind of clattering noise until the engine warms up a bit and the pistons expand a little.

 

[Anonymous]

Retorque the header bolts and see if it still ticks. If its not the lifters its probably another exhaust leak. I say this cos my 250 2v has an exhaust leak and its worst when cold because as it heats up the metal expands and therefore any gaps or pinholes decrease in size. Also be weary of crap header gaskets. I use 2 feet of half inch garden hose as a stethascope to find out exactly where the ticking is coming from, might help.

-Sam

 

[wsa111]

Dan, i have a 67 200 with about 2500 miles on a fresh engine,new pistons, reground crank,everything is new. the engine was perfectfully quiet till i ran the engine on a chassis dyno, after that a light tap-knock developed. the noise lessens after warm-up. the noise is only noticed with the hood up. the oil pressure is perfect 60 psi hot. i beleive it is a wrist pin noise or a collapsed piston skirt. another reason i hate cast pistons. you can advance the timing to say 40 degrees at idle & the noise is very much louder. you can deaden 1 cylinder at a time to pin point which cylinder, if you can, then rule out lifter noise.
i purchased a set of hsc flat top pistons sealed power 489p .040. as soon as i get my head back i'll pull the engine & bore it to .040 from its .030 over, and intall the new pistons with many other extras. if you do change pistons, a balance may be necessary because i was advised by sealed power the hsc pistons weigh 585 grams, where the stock dished pistons are 635 grams. good luck on your diagnosis. respectfully william :idea:

 

[Anonymous]

Dan, in order of the chances:
1. Lifter noise, probably from worn lifters.
2. If high mileage, like Jack said, possible piston slap.
3. Again, if high mileage, wrist pin click (although this is rare except on hi-perf engines that have been beat up pretty good).
4. Worn rocker shaft (aka worn rocker, inside the hole).

If you don't want to pull the head, which will open up a whole new can of worms, there are a couple of "old engine" tricks you can do that will help both the noise and the performance:
1. Lifter noise: replace all of your pushrods. This is very easy to do: open the valve cover and remove the rocker shaft with rockers intact (loosen bolts 1 turn at a time, all the way down, so you don't bend the shaft). Then just slip in all new pushrods. They're cheap, and this will both increase valve lift and quiet all but the worst worn lifters. Install the shaft in the reverse order, tightening 1 turn at a time to 30 ft-lbs or so.
2. If piston slap, advance the timing a degree or two. Won't cure it, but will quiet it a little.
3. Not much will help this, except a rebuild.
4. Replace your rockers and shaft. If you do this, you also MUST change the pushrods, or your old ones will quickly wear out the new rockers.

If you open the head up, get the steel head gasket (or at least one of my FoMoCo thin composites) BEFOREHAND. These are hard to find, and any other aftermarket head gasket will cost you lost power and gas mileage. Then, replace all the lifters (about $5 apiece) and pushrods. If you can afford it, get new rockers and shaft, too.

Good luck!