thenewuser

For the first time today I noticed when I go past 4 rpm the engine completely loses power and starts to slow down. Its not bogging down like its a lack of fuel it just wont go any faster but at the same time the rpms will continue to climb. Any idea what this could be?

1338xx miles
no mods
always up to date on oil changes and replacing parts that need to be replaced

Injuneer

Is it an automatic trans? If so, it sounds like the trans is slipping. That's the only way the engine can continue to build RPM, without the car moving faster.

thenewuser

Oh yea I forgot to mention that, its a manual and I just had it completely rebuilt less than 5k miles ago

BandDirector Blk98ZM6

Could be a catalytic converter going bad...but that explanation doesn't fit with the RPM's still building like you mentioned...

thenewuser

I may have exagerated the rpms increasing a little bit, I didnt push it to 5 or 6 or anything but I did notice it was slowly increasing past 4200-4300 when the power stopped at 3900-4000. I let off pretty quick after I noticed the power loss but than I slowed down to try again and saw that it was defiantly losing power at 4k rpm so out of fear of hurting the engine I only did it twice and came home to let it cool down.

Injuneer

Check the fuel pressure, with the engine under max load, at 4,000+ RPM.