Help!!!! Lifter Noise
Thread Starter
Pro
Joined: Dec 2003
Posts: 676
Likes: 36
From: Usa
Help!!!! Lifter Noise
When I drive my 73 L-48 for 30 minutes or more at around 75 to 80 mph and then bring the car to a stop at idle I hear one or more of the lifters tapping. This stops after approximately five to ten minutes at idle. I can drive the car around town (low rpm) all day long and the problem never occurs. What going on? 
Race Director
Joined: Feb 2005
Posts: 16,100
Likes: 17
May be carbon....Listen at valve covers with long screw driver...you may at least isolate issue....mine did that once autocrossing ...we misted water down carb at idle 1500-2000 rpm and the noise went away..carbon in my case...
Instructor
Joined: Oct 2001
Posts: 224
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From: Austin TX
My SUV is doing the same thing. Except when im at idle it sounds like its going to come through the valve cover. Let it sit and the noise goes away. I think mine is carbon as the egr seems to be sticking throwing the check engine light. I dont want to pull the covers as this thing has 6 coil packs overhead and quad overheads with no leaks what so ever.
Nick
Nick
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Pro
Joined: Dec 2003
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From: Usa
Thanks for the info. guys
Originally Posted by big_G
Another cause may be the oil is thinning when hot, causing a little more lifter bleed-down. Maybe additional lifter pre-load, (1/4 turn down more ) may help. 
Drifting
Joined: Nov 2002
Posts: 1,665
Likes: 1
From: Ontario
Exhaust leaks often sound like valvetrain noise, a tiny little ticking sound that seems to be more pronounced under load. Check the tightness of your exhaust manifold bolts, look for any little black marks where exhaust might be puffing out. Header gaskets are known for leaks, so if you have headers you may even want to pull the gaskets out and look at them. Some simple things to check compared to digging into your engine.
Thread Starter
Pro
Joined: Dec 2003
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From: Usa
For Certain No Exhaust Leak
Originally Posted by Boofers
Exhaust leaks often sound like valvetrain noise, a tiny little ticking sound that seems to be more pronounced under load. Check the tightness of your exhaust manifold bolts, look for any little black marks where exhaust might be puffing out. Header gaskets are known for leaks, so if you have headers you may even want to pull the gaskets out and look at them. Some simple things to check compared to digging into your engine.
It is a pronounced tapping noise and it only occurs under the conditions I described earlier.
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Melting Slicks
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From: Shreveport LA
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Originally Posted by gr8t73
When I drive my 73 L-48 for 30 minutes or more at around 75 to 80 mph and then bring the car to a stop at idle I hear one or more of the lifters tapping. This stops after approximately five to ten minutes at idle. I can drive the car around town (low rpm) all day long and the problem never occurs. What going on?
Thread Starter
Pro
Joined: Dec 2003
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From: Usa
Adjusted lifter lash on all cylinders!!!
I adjusted the lifter lash on all cylinders and drove at 75 to 80 mph for twenty five miles brought car to idle and no tapping noise. Hopefully problem doesn't come back. One concern, the lash adjusting nut on #7 cylinder is much easier to turn than others. Should I replace the nut? Is it possible the lash adjustment nut is backing off over time? 
