hey. I just bought my car a 1994 rx-7 with 60,000 on the chassis n 6,000 on engine trans n turbos!!! n im 16. Its been my dream car since i did a math project on the rotary engine (elipses n ****) n I finally got a chance to finance this beast over 3 years. I love the **** out of it. But eversince I bought this car (as is from private party) after 4500 rpms when the secondary turbo kicks in it makes a deep throated sound like an exhaust on a 5.0 stang without the crackling and the boost goes down to 0. Ive been reading everything I can find and nothing mentions this kind of noise. The turbo might have to much shaft play and would be rubbing the housing but theres on 6000 miles on it and it was brand (new not remanfactured becuase the invoice said 3000$ for just turbos n manifold and gaskets not labor!!!) and they were installed by Mazda as a crate motor package with tranny and stuff. I replaced all the visible vacum hoses without taking off the throttle body (all the hoses visible with removal of air pump and intake hoses and intercooler piping). The only mod on this car is I removed the airpump and air box. Ive tried in all 5 gears and it happens always after 4500 rpms. Also note: Previous owner had all new engine turbos etc. Put in in 99 and only put 6000 miles on it and it sat in his garage for 8 months this year.(gaskets maybe? or cracked hoses from sitting) Also, I like to do all the work my self becuase thats what I really like and I find it relaxing n **** so Im not gonna bring it to a shop, except for any kind of machining. Please Help me .....
Also Im broke because I have to make theese payments so New turbo is my last choice.... thanks

 

You just picked the wrong car to buy if you are on a budget. Your turbo problems can be many things. First off, how much boost does it make on the primary turbo? It needs 7psi on the primary inorder for the secondary to kick in. Start with that.

R.K.

 

Yeah well I wanted the car sooo bad.... just seeing it in my garage makes me happy even if its not working...
The primary turbo makes a good 10 psi all the way to 4500 rpms at WOT.... also shifting into second gear after WOT in first I get no boost.... which is probally the turbo control but I dont hear the noise untill about 4500 in 2nd even after shifting at WOT

 

youre having charge control valve problems.I suggest you check all of your vacuum lines.The one to look for is the charge control solenoid.If you have a split vacuum line your charge control valve will stay closed and your second turbo will not come online.Refer to your vacuum hose diagram in order to figure out the location of the solenoid.Good luck.

 

follow the link in this other thread and do some studying.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/secondary-turbo-not-spooling-333537/

 

Like the other post in this section, it's probably a loose or cracked vacuum hose. For the secondary turbo, there aren't that many to initially check. Pop the hood and do an inspection. On mine, I could easily see that one had popped off. Make sure you get a diagram and you inspect all of the hoses.

 

i have the exact same problem in my car, but with no noise, i dont have a boost guage, but i definately get full boost up until 45, then i get partial boost, it slows down at 4500 but still atleast as fast as a 99 model civic si or maybe gsr. it all happend in teh middle of a 2nd gear drift, went in the turn with power, came out with very little power, i thought it might be an easy fix like a hose, but honestly ive been too busy and lazy to get it checked out, kuzz i have other carz..

dude your 16 and your parents financed a 94 fd for you? geez your lucky. and its only a 3 year term? i bet your payments are a lot, and how about insurance? i hope your gonna either buy a 2nd car, or make enuf money to cover super super duper bad gas milage and repairs to your fd all the time

 

you have the common groaning noise that happens when the secondary turbo doesn't work. this noise drove me crazy til i had the car fixed.

 

My bet is your secondary boost is venting somewhere (thus making this strange noise). Check charge relief valve ("the second blow-off") and the vacuum line associated with it.
Also, check the vacuum lines at the pressure chamber - when one of those popped off I also didnt get any secondary boost. Take a look around, it should be an easy fix

 

1. Check the waste gate and pre-spool actuators for missing c-clips. This has to be done from the bottom of the car.

2. Study this vacuum diagram very carefully and trace out everything having to do with turbo control.

You will find your problem if you do these 2 things thoroughly enough.

Now for the million dollar question. You must have driven the car before purchasing it or upon delivery, was the turbos working then? If it was, most likely something you have done between now and then caused the problem. Try to back trace everything that was done.

 

Some famous last words. I hope for your sake you never get into any accidents (be CAREFUL!) or else you'll have no car and the mommydaddy insurance co. could go broke. In fact it scares me already. But I digress.

 

Thanks for the help.... I already replaced the hoses going to the charge relief becuase my first guess before I read any material is that "thing" that looked like the blow off valve because I figured it was the only "thing" that could have a hole big enough to make that low pitch sound.... After reading **** I found out it was called the charge relief valve, but everyone I talked to(none who had a rx-7, all of them were mechanics) said everytime "turbo is blown". Thoose *******. Any way yeah my insurance is actually cheaper than my previous car (a 97 chrysler lhs) some how, i think it is becuase it is older. Also, I live in ct and my insurance is 3300 a year which isnt bad for a corvette-class car in the hands of a 16 yr old. And yes im lookin for a secondary car like n old bronco or sum **** cuase i go threw a tank in 2 days haha. Also I put 5gs down and the car cost me 15 n the payments are 300$ a month. Aight well Im gonna go check the charge relief hoses (which i did but mayb i made a mistake) and the hoses to the charge control which I did not check. Also Im going to check the vacuum presure tank for cracks and the one-way valve thing if the charge control does not fix it. Thanks for the help every1 and Ill post a reply with pics of the engine bay in a few hours after I check all the hoses.