ok i was taking off in my car today. my 87 rx7 turbo 2 all warmed up and ready to go. ihave 164k miles on the car only 64k miles on the motor. Then i started getting a misfire that soon went away then under hard accel i get a rattaling noise i do have a loose belt But i really dont think thats way it is . im starting to think i have clogged injectors but im not sure. its a wierd rattaling has any one had this also its only when im above 5 grand and it dosn't do it when im it neutral.

 

Check all of your heat shields?

 

itsnot like that it rises with rpm

 

OK, alternator, air pump, A/C, steering pump bearings?

 

ok its late ill check that tomarrow thanks for the advice

 

My 90 GXL made the same exact noise I have yet to figure it out. My noise kind of sounded like somebody was under the hood with an air chisel! The weird thing was it only did it under a load. I could rev it to 8k in natural and never hear the noise. I just about check everything and I came up with nothing. At first I thought it was my tranny, so I swap it with one I had in the shop and checked the bolts on my center force clutch and they were tight and it still made the same noise. I finally had enough if it and fixed the problem the expensive way. I rebuilt a new motor and yanked the other out. I haven’t cracked the old motor yet to see if it was a main bearing or a rotor bearing yet but I will be soon. I thought it might of been injectors also but I'm running the same intake (allot cleaner one of course) and injectors on my new motor with no problems. Although I wouldn’t rule out the injectors just yet. Just to let you know I drove it like that for about a year making that noise so what ever it was it couldn’t of been to serious. I was going to drive it till it broke, but the damn thing wouldn’t break! I will have to add that I did baby it during that time with an occasional foot to the floor and screaming BREAK YOU SON OF A B*****! That noise still pisses me off to this very day!

 

Ok i think i might have had the same problem unfortunately this is the best i can describe my issues. OK when you rev the engine you wont hear any sound right but once it comes back to idle do you hear like this "tak kak tak tak then 3 secs later you hear it again??

 

I have kinda the same thing but it does it occasionally on idle. And my car also has a horrible sound like something is making a screeching sound that reminds me of a belt but it gets louder as rpms rise and it sounds like it involves metal. I'm rebuilding my engine right now tho so imma see if that fixes it.

 

could be detonation...

 

^^^^^ I was thinking detonation as well.

what octane fuel are you using?