Hi guys! been a while since I've been on here!
So For the past few months I've only been boosting about 5-6psi and spiking at 7. The stock setting for our S40's is 8 psi. It's an 04 S40. I've had the car since March, and for the first 3-4 months it was boosting fine. The only thing I've done to it since Is put in a boost gauge and ESt intake. Anyone have any ideas of what it could be?? thanks.

 

Are you sure the boost gauge is right? Maybe something is loose causing an "off" reading? Also,I would go back and make sure all the clamps and connections are tight. Also, the EST system isnt completely closed is it? So even if it looks like it is, maybe it's not and hot engine bay air is getting in.My guess is it would be one of these is the issue.

 

Check your turbo hoses and vaccum lines for cracks and tears. Also check the connection to your boost gauge to see if it is secured tightly. And like S60 R suggested check the clamps too.

 

I already checked the hoses and lines but I'll check them over again tomorrow. S60 there is no off mode, not sure what your talking about. The gauge is tight. And as far as the intake, i dont know what you mean by closed. It's an open air system, but yes its all clamped as tight as hercules can do it himself. It's only a pound that were talking here but its driving me nuts. I'll have to keep inspecting the hoses...its gotta be something minute

 

Closed meaning like the stock airbox. EST's and IPD's intake kits are not completely closed off.

 

Right, like s70driver said. I don't know how good the EST system is. Since it's not completely closed off and if not done right, maybe you are just getting too much hot air in resulting in the intercoolerhaving to work harder, hence the loss of some boost. Just a thought.

And I didn't mean off, like a light switch on and off. I meant maybe the gauge reading is wrong/getting a faulty reading possibly because of a loose hose.