ok tech guys,
put on your thinkin caps.

wed I adjusted my valves on a semi-cold motor. I ran her hard
as I always do. I drive a 99 GSR with CTR cams. Toward the
end of the day, I notice a "clacky" sound in the motor when it
revs. Later that night, I changed the oil... and tried to hear it.
I noticed a few things like less than perfect T-Belt tension so...
I let the engine sit for 13 hours. It was COLD. I set the valves and
belt tension the best ever. The engine starts, I rev to 2500rpm...
I begin to hear it. I let it warm up, the idle is perfect, no pops no
flutters, no stuttery uneven compression at idle. The car is
TORQUEY on the low cam where it usually loses power on a bent
valve. VTEC is intermittant, and the noise like a large marble in a glass
jar is resonating from the head above 2500rpm. ONLY ON ENGINE
ACCELERATION! On decel, it stops and tipping in the throttle makes
it return. GRRRRRRRRRR!!! oh also... it doesnt matter if it is warm
or cold it always makes this sound now.

cams are at 0,0
timing is at 16BTDC
idle speed is at 750
engine makes solid compression
VTEC lobe changeover is intermittant

any ideas here?






[Modified by MikeSarr_GSR, 10:22 AM 7/21/2002]

 

Like we were talking about your LMAs COULD be worn. ALSO it is your valve sadjutment. IT IS TOO LOOSE. The marble noise indicates this.

 

yea man, but keep in mind. I went through the motor more than 5 times when it was cold. 0,0 on the cams. I adjusted them to in.007/ex.008, and then went through it again and again to make sure it was right, I also tried to insert in.008/ex.009 to make sure that I wasnt too loose. if my valves were not at this spec, wouldnt they rattle all the time and not just under accleration? this sound is not present any other time. it is not present at idle, only after 25-2700rpm under engine acceleration of any kind or holding a steady engine speed.

 

ok... now the computer just took away VTEC.
it was intermittant snapping on engagement...
revised: the sound happens at narrow throttle
not at WOT at all engine speeds. now I am
limited to 5K by the ECU for a VTEC system code.
the snapping sound is similar to when low oil pressure
makes poor vtec engagement, only I have 4qts.
also the sensor did not catch anything for poor
oil pressure