[Supras] Whipping sound, or sticking valves/buckets

[berniek at technicaldevelop.com]

Christian:


    Thanks for writing with the suggestion about use of the stethoscope 
at each port.  Unfortunately, the sticking occurs so infrequently as to 
not be discernible on a cylinder by cylinder basis.  I really do not 
understand why this problem is just beginning to show up after about 
600-700 miles, but in any event I added a pint container of ValveMedic 
last night, and it seems to have done something quite positive.  Why, I 
do not know.  I'm still using dino oil for break-in purposes. 


    The sticking occurs only during warmup, never before about 15-20 
seconds has passed since starting, and it is gone by the time I can feel 
the turbo water cooling hose getting warm.  It began about 100 miles 
ago, and at times, would occur in bursts in sync with operation of one 
valve for a second or so.  It also would occur as singular events, just 
a single cracking sound.  Before the additive, it would occur perhaps 25 
times during warmup in addition to occurring in bursts lasting maybe a 
second at speeds just above idle within 3-5 minutes of starting.  
Granted, the weather was a bit warmer today, but temperatures in the 
garage do not change rapidly in the course of a day or so.  Earlier 
tonight, I got 6-7 cracking sound instances during warmup after adding 
ValveMedic last night.  What is really puzzling is the fact that it 
started after putting about 500 miles on the engine.  I suppose its 
possible that blowby during breakin could be responsible for varnish 
formation, but that really seems like a stretch. 


    Bernie