so i went to a local dyno day at modified by kc this weekend on their dyno jet...to make a long story short i warmed up my car 10 min prior to getting on the dyno, btw check engine light was NOT on..
first pull- 201hp 201 torque
second- 171hp 183 torque
third- 159hp 168 torque

mods- intake, cat bak, stage 2 w/2.8, 1 step colder plugs

they said i might have a bent valve or something
so has anybody herd or had a cobalt do this? or might know what could possibly be wrong?

-please no dick remarks, bc i have done my research and found some general, but nothing specific pin pointing the problem

-thanks

 

I'm calling Dead Intercooler/Heat Exchanger Pump..

 

GMS2 ??

If so, running the 2.8" pulley could have caused some of the issue.

Also, I noticed you have no cooling mods. Your car was prob pulling timing.

 

damn those are unfortunate numbers

 

ops typo..its a 2.9 pully
but it is a gms2
and it sounds bad but how would i know if my heat exchanger pump is bad?

 

sounds like wicked heatsoak

you were probably knocking on that last pull and iats were around 180+

 

dead ic pump all the way!!!

 

after only 3 pulls?

 

turn the car on and wait 30 seconds and look at the filler neck for the Heat exchanger if it looks like its not flowing or bubbling take the cap off and if the fluid doesnt rise its dead...

the filler neck is the tube right by the supercharger and front of the car

u ready for the 14th!!!!!!!?

 

yes if your pump wasn't working and you have no other cooling mods.

 

if the car sounds bad...might want to check for a cloggled cat, even though i think ull get a check engine light for that one. so i say also the ic pump...

sucks for those numbers tho...GL

 

thanks everone, for all the good advise so far...

 

You can pinch the lines (feel for the coolant moving through) that the coolant for the heatexchanger/dualpass runs through. You can also observe the liquid in the filler neck right infront of the supercharger. I'm going to also assume that your pump is broken. It would account for the extra decrease in power after every pull due to the system generating even more heat and pulling timing to save the engine. However check the downpipe also just incase, better safe than sorry. There is also a sort of recall out for it eventhough its not known by all dealerships.

 

the downpipe is brand new only been on the car for 2 months now....

 

Like others have said it is more than likely your pump.

 

Quick fix, whack it with a rubber mallet. Seriously, whack the Intercooler pump with a good swing a couple times if there is no flow thru the fill neck. Bandaid fix til you get a new pump (soon)

 

this is all the dust from the brushes that i got out of my stock pump when it died and hammer didnt help...i opened it up, cleaned it out and it works fine again(i only tested it, i still swapped it out with a new/used pump)

 

yea my ic pump was bad, like all yall said....so while i replaced the ic pump...i went ahead and got the duel pass and s3 he too...so my cooling mods are about done...
im gunna dyno my car again in the near future so hopefully thats wht was wrong..

 

Awesome!! Glad everything worked out for ya.