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(fyi---I'm trying to put off doing the lower end of my engine until winter.)
that being said....
this is with cylinder head with 300000km on the clock, original guides. valve grind 150K km ago as well as new seals. ALL timing components 2 months ago. I'm putting on a rebuilt ported 2.1 head next week, but I want some feedback on this nasty noise before I install...so I can decide wheter or not to put in a order for rod bearings.
Here are the symptoms:
-quite operation when cold, reving and decel.
-When engine hot: slow acceleration when parked (in neutral) quiet and smooth until about 2500RPM then it clatters like crazy (like marbles in a tim can, combine with tapping), smooths out again after 4500RPM. lifter noise at ilde 'intermittent' more pronounced heavier tap.
--Ok here is the interesting part: while driving----> smooth very quiet under moderate to heavy acceleration .... all the way up the RPM. When accelerating, ANY acceleration under POSITIVE pressure (even atmosphere to 1psi), quiet and smooth. BUT if I run up the RPM at say 15-10hg (vac), I get terrible clatter between 2000-3500RPM (and probably higher). It immediately goes quiet when I accelerate with positive pressure, or lift off the gas, as mentioned above. As well, huge momentary clatter when I lift off the throttle when shifting gears (when the clutch slightly depressed initially)
I'm thinking I have some *major* valve guide wear, or lifter issues. I'm thinking no to rod knock, because it is very quiet under hard acceleration, and doesn't have a rythmic thud to the sound.
Any thoughts? I quess it wouldn't be the end world doing the rod bearind from underneath while in car, but I just sealed the oil pan, and I opted not to do bearings in favour of lifting the engine this winter....
oh well.........;-)
any thoughts folks?
posted by 24.64.223...
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