91' v6 3.0, Engine Runs, Likely Rod Knock
Greetings!
Have had this faithful '91 v6 3.0 SR5 for a long time (owned since '99), and finally have a problem worthy of forum consultation
. 186k miles on this guy...many adventures....
The issue:
I was driving down the interstate @ 75mph, and this loud thwacking sound starts. Engine is still running obviously, and I made it home ok (yay! it still has yet to strand me...).
This sound is coming from somewhere inside the engine assembly, and i have no idea yet what in the hell it is. It sounds like metal on metal to me, feels like it is inside the block (vibration w/ hand on the intake manifold seems worst), and amplitude/frequency are definitely RPM dependent. The engine still seems to run ok with the problem at the moment...it did eventually idle too low and quit once. It's one of those ones you hear and think "man this is not good".
Water pump seems unlikely...too loud, not located nearby, and installed a new one less than 50k ago.
Timing belt assembly seems unlikely because of the low frequency of the knocking.
Discrete sounding, which makes me think piston/cylinder/crankshaft/connecting rod issue of some sort.
I video'd the issue...check it out here on youtube:
YouTube - VID_20110102_135053.avi
Anyone have any ideas? Factory manual troubleshooting wasn't much help, and would love to have a clue what I am getting into before I opt to dig in :/.
Thanks,
-J
Greetings!
Have had this faithful '91 v6 3.0 SR5 for a long time (owned since '99), and finally have a problem worthy of forum consultation
. 186k miles on this guy...many adventures....The issue:
I was driving down the interstate @ 75mph, and this loud thwacking sound starts. Engine is still running obviously, and I made it home ok (yay! it still has yet to strand me...).
This sound is coming from somewhere inside the engine assembly, and i have no idea yet what in the hell it is. It sounds like metal on metal to me, feels like it is inside the block (vibration w/ hand on the intake manifold seems worst), and amplitude/frequency are definitely RPM dependent. The engine still seems to run ok with the problem at the moment...it did eventually idle too low and quit once. It's one of those ones you hear and think "man this is not good".
Water pump seems unlikely...too loud, not located nearby, and installed a new one less than 50k ago.
Timing belt assembly seems unlikely because of the low frequency of the knocking.
Discrete sounding, which makes me think piston/cylinder/crankshaft/connecting rod issue of some sort.
I video'd the issue...check it out here on youtube:
YouTube - VID_20110102_135053.avi
Anyone have any ideas? Factory manual troubleshooting wasn't much help, and would love to have a clue what I am getting into before I opt to dig in :/.
Thanks,
-J
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