where's my BOOOOOOST ?

[audinut]

Hi guys had the s2 out today and im only getting 0.9bar boost with WOT in 3rd and 4th gear

since im struggling to find the correct process could someone please list the points to check in an order so that i can eliminate each one in a methodical order

apologies for posting an often posted question

[UrS4boy]

..since im struggling to find the correct process could someone please list the points to check in an order so that i can eliminate each one in a methodical order :

1. Find the moisture trap and check to see if the boost/vacuum hose is connected to it. http://forums.quattroworld.com/s4s6/msgs/20401.phtml

2. Boost leak test:

http://www.s2forum.com/forum/showthread.php?t=63974&highlight=boost+leak+testing

That's for starters.

[audinut]

1. Check

[macspring]

What spark plugs are fitted, change from Bosch to NGK, worked for me, my car is now fine.

[audinut]

changing your spark plugs increased your boost?

[macspring]

No sorry, it stopped it over boosting and going into limp mode. So was just mentioning it as it may not be something that one might think of checking / replacing.

p.s. Don't go for an RS6, stick with your current S2. Existing suspension problems can be overcome.

Mine - Had to do the starter, then brake servo after first changing the brake master cylinder, and before that the bomb whilst chasing a brake issue, but as mentioned the the cause of the fault was the brake servo. So also had to do two flushes of the brake system, one after the brake master cylinder, and one after the brake servo.

You are not alone in your irration with these cars.

But running sweet now, but for how long ?

[audinut]

2. boost leak check carried out

Used a smoke machine and found a leaky crankcase breather pipe , and a leaking boost gauge - both changed and now boosting at 1.5 bar in fourth with WOT

Im pretty convinced i have no boost leaks now as the smoke machine is quite effective

[prj]

Smoke machine is good for testing NA cars for vacuum leaks, but not as good for testing turbocharged cars I have found, as most of them pressurize the intake very little (usually 2-3 psi?)
Sometimes there are leaks which are apparent only after a certain pressure, and then you can't find those with the smoke machine, as they seal themselves again after pressure drops.

Though it seems you got your boost back so in this case it helped.

[audinut]

thanks for the advice , maybe i will use the standard method just to check for definate