I changed both valve cover gaskets this weekend and decided to do a little carbon cleaning while i was at it. When i put together the intake manifold and all the hoses and valve covers i noticed something strange on start up.

The startup was rugged and the idle was very rough. After about 30 seconds the car started to bogg, and it just got worst with time.... i shut her off to make sure everything was tight and hooked up, everything was.

There is a small hissing sound, i dont know if air was being leaked or being sucked in, around the intake and manifold.

Can anyone offers some advice on what the problem might be?

 

Check for vaccum leak at Throttle body and IACV gaskets especially if u reused an old one.

U sure all hoses are accounted for and clamped off?

 

Check your EGR tube where it connects to the back of the UIM. Had the same problem happen saturday

 

Double check the routing of your vacuum lines,is it possible you got some mixed up?Easy enough to do.

 

thanks just got home from work, ill double check all the suggestions

 

let us know if you got it fixed, or if you didnt. Believe me I was freaking out saturday, 4 hours from home and the car wouldnt start and run....I was like WTH!?!?!?!

 

Check the vacuum hoses on the throttle body. They are hard to see. I left one off and the car didn't like that.

 

Would a missing egr tube gasket cause this? I just did a egr tube cleaning job & my max is breathing harsh too.