this has not happened to many time but, im flooring it in first and i pass 5k i hear a furious rattle either out of the engine or the tranny, im gunning it and then it's like i fell no more power afterwards, but the car is still going.
could it be a throw out bearing issue, clutch slipping, or something else.

please help...

 

Well I guess the list of things this could be is extensive, but I was experiencing a similar problem after I modified my stock air box. For me it seems to be a problem of going lean, I don't have a wideband, or narrowband yet to see exactly, but adding fuel up top with my SAFC II has worked to correct the problem for me.

 

That could mean furious rattling = detonation....that's not good!

 

"That could mean furious rattling = detonation....that's not good! "

yea dude be afraid. if thats the case...it's all over.

 

dentonation how? how would that work on a rotory

 

Check the timing on your car. I was experiencing some detonation and it turned out my timing was off. Get yourself a cheap timing light and check it asap. Detonation can ruin your motor.

 

I hope this isn't your problem, but when my transmission went bad I had a similar problem. I couldn't rev higher than 4000rpm but I could still drive. Just a thought.

 

Not well. Sure way to break apex seals.

If the car is an NA, then I would not assume detonation as the cuase. If it is a turbo car, you need to check the A/F ratio to make sure you are safe.

 

yea it's a non turbo 86, but ill usually hear the same noise at a stand still with the clutch pushed in, it only does once in a while

 

i had something happen to me that's sorta similar. i floored it on first gear redlining it (to clean the carbon a lil), and when i shifted to 2nd gear, i got to about 7500rpms and the car started to struggle. couldnt do it at 3rd gear cuz of traffic, but i did it twice and on 2nd, it just struggles after 7500. i was thinking maybe one of the aux ports wasnt opening but it redlined fine at first gear. (sorry for the hijack) - any ideas? tranny maybe?

 

btw..it's a S4 n/a

 

Struggles after 7500 RPM on an S4, where the redline is 7000? I hope you've got some kind of big port and internals...cause there's really no reason to bring it past 7500 rpm. Not too much power is being made up there...

James

EDIT: The AUX ports open at around ~3800 rpm, so if you weren't feeling a lack of power until 7500 rpm, it's probably cause the motor isn't making power up there

 

Sounds almost like something is loose. Check ail the exhaust heat shields.

 

Yea, what Aaron said. If it does the same thing while your sitting still then its not detonation. On a side note you might check the ring gear on your flywheel. The one on my stang came loose once(all the tack welds broke...lol.) I just pulled it and had a machine shop reweld it on. That fixed my problem. But I dont even know if the flywheels on the 7 have the ring gears welded or cast on to them. Just and idea.
Jeremy