Exhaust sound or valvetrain - i cant peg..

[UBER6]

guys, maybe someone has run into this. 86 buick w/ATR headers/ATR external wastegate; sealed up w/permatex high temp red - has annoying "puttering" sound under passenger side floorboard when driving off..- thought it was the crossover pipe; took off and sealed it up...did all exhaust joints...; checked w/soapy water all joints...rats - still hear this putter sound - not heard at idle - give it the gas and distinct puttering...could it be valvetrain? has 145K miles (replaced timing chain/gear assy)..

same valvespring, rockers, etc...hmmm. what would be a symptom thanks for any pointers.

 

[corymc]

you check the cat/dump pipe to the exhuast?

 

[UBER6]

yes. welded up tight....

 

[corymc]

ok i have a noisey valve train but its a full roller

 

[UBER6]

heads are stock...if it were a tappet sound..that would be heard at idle?

 

[SNOWBIRD]

have a buddy create some backpressure by blocking exhaust pipes with shop rags while you listen for exhaust leaks

 

[SNOWBIRD]

dont totally block ,,

 

[SPOOLFOOL2]

Bottom of cyl #6 exh. manifold gasket leak?

Felpro header gaskets suck!

 

[UBER6]

i will try your fixes and get back - thanks guys..