Turbo Bypass Valve Issues

Brett Dikeman brett at cloud9.net
Wed Apr 17 19:55:07 EDT 2002

At 10:27 PM +0000 4/17/02, Jobe Tichy wrote:
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>Ever since I have owned my 20v, I have noticed a "sputtering"-like sound when
>I would shift through the lower gears--kind of cool sounding.  But, I have
>also had this corresponding 1.6 max boost issue.  I have read up a bit about
>the turbo bypass valve being the cause of this sputtering sound
>because it could
>the diaphram inside rattling.  I have heard there is also a corresponding
>"groaning" sound with bypass valve problems but I do not have this.

I'd recommend checking the condition of the control line,
particularly where it sneaks through between the intake pipe and the
heat shield up to the back of the intake manifold.  Outright
replacement isn't a bad idea considering how cheap the stuff is.
Basically, it cooks until it becomes so brittle it snaps or cracks.
A very permanent solution is to thread some copper tubing over by the
area that gets very hot, or reroute the hose around the
front+passenger side+firewall, as I think Phil has done and had good
luck with.

Also, use a mityvac or similar vacuum pump to apply a vacuum to the
control port; it should not leak at all.  Lastly, you shouldn't be
able to blow any air through it with no vacuum on the control
port...and it should take a decent amount of pushing with a finger to
get it to open.


"They that give up essential liberty to obtain temporary
safety deserve neither liberty nor safety." - Ben Franklin

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