I have had a '04 RX-8 for about a year. The other day all of a sudden the engine started running ruff and the check engine light came on. I took it to see what that was all about. Said it was a misfire, so I changed the plugs, wires and coils. Now runs better than before and no check engine lights. My problem is I have a pulsing hiss coming the engine. Can someone tell me what this could be.

 

AC Compressor engaging and dis-engaging? this will create a sound similar to your description as AC coolant is routed through the interior components.

Could also be a vacuum leak. and an assortment of other things.

is the car running OK now?

 

when do you hear the hissing?

 

The AC is not on when I hear the noise. I hear the noise when the car is idleing.

 

i have that same problem on my 04... the tech at the dealer said it was normal.. and i trust him.. he said it was something with the AC... the AC does not have to be on to hear this

 

I went out and checked it over and the sound is coming from the back of the engine under the air intake. Now when I step on the gas the noise speeds up sounding like bird cherping and then quit.

 

Do you have aftermarket intake on? Or did you not tighten up the intake somewhere when you were doing the wires, plugs, and coils?

 

As far as I know it is the stock intake, its the same one that was on it when I got the car. All I did when I put plugs Etc on is take the air box and hose from that to to MAF sensor.

 

There is a vacuum line tucked under the back of the intake area you seem to be noting is the source of the sound. Almost impossible to see from in front of the car, but if you reach around you will either feel the hose connected there, or a connecting nipple sticking out if the hose is detached.

 

Finally took my car to dealer to get it checked out. Come to find out that it was a vaccuum leak. The worst part is the rough idle. Still doing test on it. Was told by a friend that works in the service dept it might need a new engine. Will find out after the holidays.

 

Will I am going become one of the NEW MOTORS people.Was told today that they are going to replace my motor. It is on order now. They said NEW MOTOR. But wondering if now or refurbished.

 

^^ there are new ones coming out right now. One of the guys at the rebuild plant is a member on the site.

 

Auto or manual?

 

Automatic

 

It probably is new. I think the new engine plant is in VA, and it sounds like they have shipped a lot more autos than manuals, so your odds are good.

 

Yeah the guy that is in this club is in Colonial Heights Va. I said if they knew where it was coming from and they didn't know. Said it would be here in 3 or 4 days. Hopefully get car back the 3end of next week if I'm lucky. But you know how the dealers are they take their good time.

 

I talked to the member at the Va-reman and he said that "Williams Technology" still has auto engines. So it most likely will be built by prisoners.

 

Now that makes me feel real good about prisoners doing it.

 

got a reman today and it don't sound to good but a only put about 40 miles on it untill i found a lose hose on it as well!

 

Note that reman engines are just engine cores. Depends on your local tech to transfer all your engine stuff (plugs, hoses, manifolds, engine accessories, etc) onto you new core. Screwy, mistake prone swap procedure IYAM.

 

at least you got a new motor for free, cool!

Did they make you furbish proof of oil changes?

 

They did all the oil changes since I have had the car. All I did was sign some pages and leave with the car. I also has a brand new CX-7 to drive while they worked on mine.

 

When was your car first purchased? Thats the day your warranty started. How many miles are on it?

 

I got the car in June 07 with 21000 miles on it. It now has 33000 on it

 

I have the same problem dude. I'll try changing the plugs, wires and coils as well. I hope it will help.