y dosent my dump valve hiss when letting out?

Answer 1

If it used to but now doesent, it could be the diahram inside. Not sure if you can refurb or replace it. Best to contact your supplier.

Answer 2

Hi Alan,

There is a common reason for a dump-to-air valve's not hissing, they are mainly designed for cosmetic reasons, but lengthen the life of a turbo ( as long as the engine isn't thrashed regularly lol!) If the catalytic converter is blocked even partially, the back pressure tends to play havoc with dump-to-air valves, turbo’s, HDi and CPi engines. Before spending anymore money, try a bottle of catalytic converter cleaner http://www.autobarn.net/chcat-1.html

This is sometimes called cataclean, this is around $6 - $10 (approx £3.50 – £6.00) All this said, some D2A valves don’t hiss at all!

Good luck hope it works out and not to expensive!

Answer 3

Not all blow off valves make a hissing sound. In most cars the Blow off valve is the re-circulating kind as it vents back into the intake which is smog legal and also helps keep the turbo spooled up for better performance. The atmospheric release blow off valve is the one that makes the loud hissing sound and most of these are after market and not smog legal.

Answer 4

You mean your air ride dump valve? I had a truck that didn't hiss once, and somebody told me that it was because the air was recovered and put back into the tanks.
The more I think about it, that seems a bit pointless, because the air compressor will always make more air. The benifit of having such a system would be far outweighed by the fact that it would just be one more system to fail.

Answer 5

gases not burning propel or dump valve is broken

Answer 6

blow off valve? it usually sounds like rubber flapping in the wind (which is what it really does anyway)

Answer 7

It may have mufflers on the exhaust ports.