I have done some searches but their hissing seems to a little different than mine. I recently noticed a hissing sound at 0 on the boost on up. Any time the turbos spool up and there is boost I hear a hissing sound. It sounds like air being released. I have looked and no hoses apprear to be loose or off. I did notice water sprayed on some hoses but can't find where it is coming from. The sound is on the drivers side. I also noticed that the boost goes 9-7-9 not the 10-8-10 that it used to do. I would appreciate any help as always. Thanks.

Danny

 

Oh by the way I am still very much learning the search button. I just wanted to apologize in advance if I missed a thread.

 

Try Searching "boost leak" In short, carefully inspect all the rubber couplings from the turbos to the manifold. It's best to remove them and turn them inside out a small tear can be hard to see. I find it helpfull to pressurize the entire intake track, then the smallest leak becomes obvious.


https://www.rx7club.com/3rd-generation-specific-1993-2002-16/custom-tools-471345/

 

danhag10 what your saying sounds like a boost leak for sure. Check your Y-pipe, then check your intercooler. You said drivers side so make sure you top and bottom hose you your intercooler don't have holes in them, esp. if they are the old stock ruber ones.

 

So would a boost leak cause the water to be sprayed. I would post pics of the area but it keeps telling me my file is too big. Thanks

 

Sorry I was posting that question while you sent yours. It's not stock intercooler. It's a Greddy FMIC. If it is a boost leak, what are my options? Or better yet how much will it cost me? Thanks guys.

 

My 94 have a strange hissing sound under boost...it has been a year. A local rotary perf shop said the sound was from a worn out LIM gasket. Well...being a Mustang gear head since 1981, I thought any vaccumm leak would make the car run like chit...instead mine run fine even with the hissing sound.

Last week I finally got a boost gauge installed...sure enough...boost pattern was not like normal. So I check and found:

1. The 1" dia hose to the Y pipe was lose(primary turbo), litterally it can be rotated back and forth.

2. The one way check valves (2) are leaking.

Currently car is under operating table...should be running by this weekend...and I will keep everyone posted.

Oh...if your FD doesn't have a boost gauge...PLEASE get one...I am so glad I did.

TIA

 

It looks like one of the housings connecting the piping from the IC has a crack in it. But the leak spraying coolant and water is somewhere near the oil filter. There's a coolant leak somewhere. I can see where the coolant landed. I just don't know where it came from. I am new to working on my car period, let alone a FD. But the feeling driving the car makes the learning that much better. Anyone near KC that would like to help take a look? Or maybe they wouldn't like to, but feel in the bottom of their hearts to do some christmas charity, let me know. Or anyone know of a shop to take it? Thanks guys.

P.S. Anyone know how to attach photos w/o it saying that the file is too big?

Danny

 

There's a coolant hose that connects to the back of the throttle body, it's just above your oil filter. Check that hose, I bet it has a leak.

 

probably a split coupling, you'll have to remove and inspect to locate the problem. Most likely the Y-pipe coupler if your still using stock pieces.

 

I know this is a stupid question. But where is the Y-pipe located and what does it look like?

 

check all your couplers, the Y-pipe is generall the first to let go.
This is the Y-pipe the large end (where the green rag is sticking out second picture) is where the coupler is the other two ends bolt up to the turbo's

Here is how it looks on the engine

 

Thanks.

 

The coolant leak could be the coolant hose on the firewall side of the TB, or the short hose directly underneath it. It is very unlikely to be related to the boost leak.

There's a guy named Mahjik in KC - although he's very busy, he would probably direct you to some local resources. He sorta knows what he's talking about

Photos should be 100000 bytes or less. That usually means I need to crop, resize, and lower the quality of any digital pics.

Dave

 

is it really necessary to have a Y pipe polished like that? No doubt it's very nice but hardly visible under the hood (maybe just a little)...not big fan of polished stuff...IMHO.

 

This is the top of the stock y-pipe (where the red coupler is) if you fallow it back it goes down and there's your y-pipe. You don't need a polished one it's for looks, just like a polished manifold. I'd go through and check all your couplers for cracks and make sure all the clamps are tight. If a coupler is slipping off you can sand the area a little to give it some grip.

 

Thanks guys for the help. I haven't had a chance to reexamine the hoses, but I'll let you know as soon as I do. Also, is it bad to drive the car if there is a boost leak. I don't want to damage anything by driving it, but right my other car is in worse shape than the 7.

 

If it is a boost leak, and if it is bad enough, you could over-rev your turbos and fry their bearings, so you might want to take it easy until you fix it.

 

It's not necessary to do anything to these cars but maintain them in proper working and serviceable condition. But everyone is different. I happen to love the way the engine looks and there's allot of aluminium under the hood. I've done the reliability mods, and even did a few that I wasn't going to (more power) and after seeing some of the engines these guys have displayed at car shows, got the bug to polish some parts. If I had a picture of a non-polished Y-pipe I'd have shown you that . If you ditch the air pump, you'll find all kinds of things you can see in the turbo area, get rid of the stock air box....wow more stuff.

 

I noticed the sound goes away when the second turbo kicks in if that helps.

 

Makes me wonder if your not hearing your CRV venting till the secondary turbo comes on.

 

Sorry but I have busy and haven't had a chance to reply. I know it is never smart to take an FD to a Mazda dealer for engine work. But would it be ok in this instance to take it to check the hoses, crv, boost leak, etc. to find out what's causing the sound. I was also wondering if it would be okay to take to them to install a fuel pump, injectors, and so forth. There isn't a place to take my car around me and since I don't know much yet on how to work on her, I just figured they might be better than nothing. Thanks as usual.

Danny

 

Take a few pics of you engine bay and post them up. Might give some of the experts (not me) a better idea, of what is going on. I wouldn't suggest going to a Mazda dealer, I'd scower the internet looking for a rotary specialist.

 

Take your car to someone that knows these cars ............ not the dealer. It's obvious that you don't know much about these cars, and need some help. Someone already made a suggestion (in this thread) about who to contact for the name of a shop

 

I'm in full agreement on this as the dealer can't handle an oil change without screwing up these cars.