Raj77

My 2014 does it too.

KesselRunner

11 Mississippi aaaand.... Thump. I think its normal

benelli_t

Same here...sounds like vaccum

GriffFX4

It is normal. Another thread on here somewhere explained it. It's a EB thing...it's engineered to do this but I can't for the life of me remember what it was....

GriffFX4

Ok I've seen it explained as the waste gate pop off after initial startup and the turbos spin up but then the idle comes down, the pressure has to go somewhere... Typical FI or turbo mechanical stuff here...

However, this was not the same explanation I read but this makes more sense.

JoeHeff

Ok this may not make any sense but after hours and hours of searching on this forums with many different combinations of search terms, this is the closest I could find to what I am experiencing with my truck... except mine is a 1997 4.2L v6. Are you guys certain this is the turbo specifically? I am wondering if my truck has something like a secondary air injection pump like the jetta that I used to have, or something else that similarly only operates upon engine start. I haven't had the truck long so I am extremely inexperienced with this engine.

kevin7898

There is a ssm on it. Completely normal. All 3.5 ecoboosts do it