ok i just bought a 2004 rx8 124000 miles been sitting for a year. the guy i bought it from we started it up without a cat and it was loud and smelled really rich and smoked alot. it didnt have enough power to even move(automatic). so i get it to my house reconnect the cat and start it and have to rev it to 2500 and the rpm hops then smokes pouring out like its flooded . if i rev it over 2500 it sounds like metal on metal knocking when i let off the gas it idles for a sec then dies and takes 2-3 times to start back up any advice? im in the tampa clearwater area...

 

Metal knocking sound from the engine is never a good thing. You probably have severe internal damage.

 

the guy i got it from said it lost compression in the rear rotor and he broke the spark plug in half(which he didnt and i re connected) but im new to rotary and need to know whats up with this vehical! the cheapest i can find a gasket kit with apex seals for is $1200 is it cheaper to pay $2200 and get a engine from mazda?

 

Assuming you will be pursing a fix, here are the key pointers to know:

1) A rebuild is a rebuild. You can't only rebuild part of the engine. In order to replace any piece of the engine block, you have to do a complete rebuild. Side effect of only having 3 moving parts.

2) Not all rebuilds are completed equally. A garage rebuild is usually the lowest quality, as often there are shortcuts done for the sake of saving money, however Mazda remans from the dealer are sometimes not all that much better. Probably are, but they have more than their fair share of bad apples. I'm not sure who quoted you $2,200 for a reman, but that's quite cheap. That sounds more like dealer cost, than dealer retail. Retail prices for the reman usually are quoted $4k-$6k, depending on how badly the dealer is marking things up. Mazmart (forum vendor here) has quality rebuilds that will outlast the Mazda remans for in the ~$3k range. If you bump up the price further to $5k or more, you can get perfect hand rebuilds with port work hand cut seals, perfect clearancing, etc... from one of the several top notch engine builders, like BHR, Pineapple Racing, BNR, and Pettit.

3) By far the cheapest option will be to buy a used engine (you will need a 4 port engine from a 2004 or 2005 automatic transmission equipped RX-8, all other engines will involve lots of custom work and/or additional parts), however used engines are used, and you often can't be sure of what you are buying. The engines are usually priced accordingly.

 

the 2200 is for the engine and its 3200 before tax without core and thats from the mazda dealer here in new port richey... i am use to rebuilding motorcycles,diesels and piston motors but im new to rotary... i am just hoping its just the apex seals like the previous owner said but i know one thing about rotary and thats not to buy used because you dont know how they drove it and i wouldent mind rebuilding if i could find the parts for a little cheaper . i mean 1200 just for the gaskets is alot i mean its more expensive then buying parts for my harley lol

 

You can find the seals for cheaper, but not by much.

You won't get a rebuild for cheaper. JUST the apex and side seals and re-using everything will give you an engine that will last 5,000 to 10,000 miles for about $750 if you do it yourself, AND the major pieces aren't damaged, just worn.

However, with that mileage, chances are that the irons need to be lapped and/or replaced, and the housings need to be re-chromed and/or replaced. The e-shaft and rotors are probably fine under most circumstances, but with metal banging on metal in there, you have a good chance at having at least 1 rotor damaged from physically impacting it's housing, which means that housing is beyond repair too. A brand new housing retails for $1,100 under Mazda's Motorsports discount program, $2,000 normally. A single housing.

If you want a shot at rebuilding, then pull the engine and tear it apart. We love to see pics of the internals, and can help guide you on what is reusable.

 

im all into learning new things and new things are rotary so another day or 2 and i should be able to bear hug the motor out of the car and how bad are these motors on vaccume hoses when i was pulling it apart there were a few hoses disconnected by the intake and throttlebody?

 

There aren't many, and plenty of info available on the routing. Far fewer than FD's that's for sure

 

whel if one is dosconnected would it make it run like crap mabe or idle weird?

 

Yup, it certainly can. There are a whole host of things that can cause that:

- Failing plugs (every 20-30k)
- Failing wires (every 30k)
- Failing plugs (every 30k)
- vacuum leak
- e-shaft sensor fouling
- MAF dirty
- compression loss
- clogged cat
- O2 sensor failure (front)
and probably a few more I'm forgetting at the moment.


However, the only thing that will make metal banging sounds from the engine block is pretty severe damage to the e-shaft and/or rotors, and if you have that, then the rest is pretty much an afterthought.

 

whel il take a look at the cat my next day off im dealing with issac at work right now but it ran better with the cat off but still didnt hold idle and starting u could smell the ritch gas and the drivers rear exhaust is making the bumper change colors... ive loved the cars since theve come out and love different rare vehicals and cant wait to get this thing running ... i traded a running cutlass for it that i had about $2500 in i figured the body with good apholstry inside was well worth it just weird the first time i looked in the trunk to find no spare tire but im looking foreward to be driving a rotary and all the differences it comes with and if a get the money il throw the turbo i have sitting in the garage from the last project i had on it with a little boost...my last car was pushing 23psi but im not going to do that to this motor

 

Yeah, learn all you can about boost on these engines before starting. It isn't for the faint of heart, but then if you are willing to tackle this challenge yourself, you might be fine.

For an estimated purchase price of $2,500, you probably didn't overpay, and starting out without any cash tied up in it is a good place to start.

 

so whats the deal with boosting the rotary its not like you can make it lower compression so is it just fuel upgrades manily and tricking the ecu to make it think its getting vaccume still? im not going to be putting crazy boost to it if i do it make 5-7 to get by and help with gas milage some til i put my foot into it(all in time)

 

Check out the 2nd thread in my sig...

The problem is all that when it comes to boost, the boost is a bull in our china glass engine. And most people are startled at what very little psi can do to our engines, both in what it feels like to drive and how destructive it will be.