valve tapping at idle . . .
 

1997 Eclipse 4 cyl (the Chrysler engine). 180,000 miles.

Light valve tapping noise when engine is at idle (800 rpm). Above say about 1100 rpm the noise stops. Engine runs smoothly anywhere above fast idle. Radical throttle work, no adverse affect, engine runs just fine.
Been like this for several months.Just kept waiting for a leaky lifter to come
back.

Now suddenly it's a hash rattling noise. But again, anywhere above fast idle the engine happy as a clam!

So I pulled the valve cover for inspection. Everything normal. No surprises at all. Feeler gauges (0.003) with heel of the cam down is no-go. I assume this is normal, and the lifters are pumped! Or will I have to get a socket on the crank and turn the engine?

Posibilities:
1.A lifter (or lifters) is not pumping up at idle rpm.
2. Valve stem is binding in the guide.
(Add a few rpm and the valve has enough energy to close properly!)
3. Week valve spring.
4. Any combination of the above.

The engine did seriously over heat and the head gasket failed.
Had the dead shaved and reinstalled it.
Restart was normal except for the fact that the light tapping started right then and there! :eek:

Now I'm wanting to simply put a new lifter (or lifters) in!

I believe this can be done by simply lifting all the bearing caps on the offending camshaft(s) except perhaps leaving the ones on the drive wheel end just loosened a bit), lifting the end of the cam enough to slip in the new lifter. (It's numb four cylinder I'm sure.)

I hope I have presented the the symptoms well enough to cleanly present the problem. I deliberately delayed mentioning the blown gasket to maybe help the diagnosis process.

Any comments much appreciated.

Well then - how about this? With the valve cover removed will oil spray around?

Finally got some time for the Eclipse!

Indeed cam followers and hydraulic lifters can be removed w/o removing the cams.
At least on cyls 3 & 4, that's all I had time to play with.
I rotated the crankshaft (socket on the drive pulley) to put the heal of the lobe(s) on cyl 4 at the follower.
I released the beating caps on the cams in a sequence of 180 degree turns until each bolt would turn freely between thumb and index finger.
The followers practically fell out! The lifters have no conflict with the cam lobes, came out with persistent pull.
It appears that at no time will any of the lifters have conflict with cam lobes.
Cyls 1 & 2 likely will come out w/o problems.
But if they jam up it may be possible to get enough room for release by prying up on the shaft, lifting the cog pulleys against belt the tension.
Maybe.
Carefully
Hope this is helpful for those who have shown interest.

Update. All lifters and cam followers can be removal for inspection/replacement.
There's a $20 tool to depress the valve stem(s).freeing the follower for removal.and then the lifter(s).

Now I'm getting different answers for torque settings for the bearing caps, (4mm) and end caps (6m).
The library volumes of Chilton has no info on any torque settings.. ?f
I can buy from nearest parts store, but wondering if they have no torque info for these items.
Anyone verify whether Chilton or Haines actually have torque settings?