Hissing from engine bay when I apply throttle.

[Takanami]

I have 1998 Honda Civic EX Coupe. When I apply throttle a hissing from the passenger side of the engine bay starts and stays till I get off the throttle. What might this be?

 

[HeX]

A vacuum line leak perhaps. Pop open the hood then manually press the throttle and listen for the "hiss".

 

[Takanami]

yeah I have tried that. at the same time the hiss started the gasket on the vtec solenoid blew.

 

[HeX]

Well, did you replace it?

 

[mc360]

Cold air intake?

 

[Takanami]

I indeed did replace the gasket and the cold air intake has been on for months now, the hissing just started Monday.

 

[HeX]

Thats an odd intake set-up. Did you do that, and why? Recheck all the fittings.

Also, be a little more clear on your timeline. Did replacing the vtec gasket resolve the hissing? Did you continue throttle testing at the engine bay? Did you narrow down the area in which the hiss is originating?

 

[Takanami]

Gasket did not solve the issue. I continued throttle testing from the engine bay. I have discovered the car it producing little back pressure and wont rev over 4k. I thing the hiss is coming from the intake. I have tested with multiple filters and with out any filter.

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[nd4sped]

What hose is unplugged here? Also the hissing could simply be the short ram intake you have. Do you have any issues with your idle?

That intake also looks like one of those Matrix/Pep Boys kits from awhile back. Yours looks fairly new, shiney

 

[Takanami]

Thats not a spot for a hose its a mounting point. It looks like its a hole in my exhaust.

Thanks to everyone who tried to help the noob I am.

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[mc360]

That's a grounding point for the valve cover. Also 90% time the hissing is from the cold air intake, my friends car did it and mine did it when I installed a short ram. If you have the stock air box put it back on to test it, if not remove the short ram and install the filter on the throttle body, the hissing comes from the iat sensor and grommet in the intake

 

[Takanami]

Again not the intake. I wouldnt lose power the way i am from a cold air intake plus i had it on for months with no such hiss.

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[mc360]

Maybe try putting a piece of pipe to your ear and listening around the the intake manifold if you think that's where it's coming from

 

[Takanami]

As i stated in an earlier post it turned out to be exhaust issue.

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[HeX]

Im curious to know where this hole is in your exhaust