Quote:
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Originally Posted by skunkworks
This is my thought - The lifter "pumps" up until there is enough pressure between the rocker and the lifter that there is minimal oil flow though the top hole. Now if the top hole gets plugged it thinks it is already pumped up even though it is not.
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Slightly different take...
I used to think that the oil pressure was directly responsible for holding up the lifters like some old American hydraulic lifters. Instead, our lifters have a one way valve, a reservoir and a small bleed-down orfice that actually provides the resistance to compression independent (at least for a short duration) of oil pressure. (Case and point - you cannot compress them easily even with zero oil pressure!)
I believe the hole on the top of even the 1G lifters may be HUGE compared to the internal orfice that is critical for proper bleed down. Whatever is responsible for trapping air or causing the one-way internal valve from sealing correctly may be the "noise gremlin".
(Should be easy to identify a noisy lifter because it will be easy to compress)
Clint
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1991 Stealth RT/TT - Firestorm Red - 193K Miles / Original Owner
Maint: Castrol 10W40 / Mitsu Filter / Rislone
Replaced: 2X clutch / 3X brakes / 2X front rotors / 2X ABS HU / 1X NGK Plugs / 1X Ball joints / 2X Antenna mast / 1X Active exhaust cable / 1X Windshield / 1X Fuel FIlter / 1X Struts / 1X rear rotors / 1X Front Head / VSS / 1X rear wheel bearings / 1X Transfer case (warranty) / 1x Tie rod end (drivers side)
Overhauled: Starter, IAC, BISS, CV Boots
Upgrade: SilverStar Headlights / ebay "Xenon" Fog Bulbs (no more yellow!)
A/F Gauge / MAP - Electronic Boost Logging / MMCd Data Logger
Pending Projects: Steering Rack