My boost has for 2nd time in 24 hours dropped to 6-8psi!!!!!from the usual 13-14psi wots wrong??

 

03/1996 WRX

 

First guess. Temperature. Its been really hot the last couple of days. Take thh car out early in the morning and see if it's any better. I reckon I lose 5-10Bhp when its a hot day like this.

 

Has it been hot?

My car's boost did this while out in heavy traffic in very hot weather yesterday - I'm putting it down to the engine getting too hot in the sun. (Someone called it "intercooler heat soak" at a Scooby meeting)

 

Seems great minds think alike (fools seldom differ) Wonder which category we fit into?

 

Someone in the drivetrain forum will tell us no doubt..

 

First happened last nite about 10ish,slight mist in the air a bit cold,then today the same boost down to 6-8psi then after 10-15 mins back to normal.Also a sort of 'FFfff'noise when holding boost,but been doing this over 10 months now.

 

Not heat related then

Try the check engine light flashy diagnostic thing.
http://www.shell.linux.se/wkc/subaru/ecu.htm

You could try the infamous "earthing mod". I know some people say it doesn't work, but I found that adding one substantial wire between the battery -ve terminal and the manifold helped out a lot - the engine ran smoother and started better. There was less measured resistance between the battery and the block. (From 5 ohms to 0.5 ohms) This has to help things along a bit. Also may be worth checking the earthing connections to the ECU.

There are, however, lots of things it could be so start with the cheap to fix ones!!

 

sounds like the boost solenoid playin up to me???
Had an oil change lately?
Rob

 

Major service 3000km ago.

 

probably not an oil contamination prob then..
Think you need to clean out your boost solenoid.
Remove the pipes from your boost solenoid and spray brake cleaner through them, try to connect them up as soon as you can after spraying cleaner through them and bring the car on boost.. this will open tha solenoid and 'wash through' the solenoid..
The problem you are having is exactly the same prob as i had although mine was due to overfilling the oli lightly and contaminating the solenoid, day to day use can also block teh solenoid causing low boost pressure..
i am sure that the boost prob will clear once you have cleaned the solenoid out..
Rob
let us know if it is cured, if not there is another couple of things to try

Also read this link solenoid problem

 

Thanks for your advice tweenierob.I'll give it a clean tomorrow nite and will let you know wot happens.Cheers mad555

 

you can also use the "diagnostic mode" to pump brake cleaner through the solenoid. Connect the green wires (I think) only under the dash to make the car run the fans and click the solenoids etc. while you (very carefully!!) spray the cleaner through the solenoid.

Did mine a couple of months ago when I accidentally overfilled the oil. No problem with it now