i have a leak?

[upgrading_86]

So I started searching for some awnserers and didn't seem to find anything helpful I was wondering if a exhaust leak right under the exhaust manifold can cause me to lose massive boost and last I checked I vacuum was at -10 help please

 

[rlacasse1]

It'll hurt your spool some, but it's not going to kill how much boost you will build.

How much of a loss are you talking about?

 

[Alucards_blood]

A pre-turbo exhaust leak would definitely affect boost pressure and response. It's like having an open wastegate but on a much smaller scale. In order to maintain the same amount of pressure vs a car with no pre-turbo exhaust leak, your turbo will have to work much harder (higher RPM shaft speeds) to maintain the same amount of boost as the other guy. In the long run, you'll overwork the turbo which will lead to premature turbo failure. I'd replace the gasket if I were you.

And for your vacuum issue, I'd do a boost leak test.

 

[Colt4G63 also]

A pre-turbo exhaust leak would definitely affect boost pressure and response. It's like having an open wastegate but on a much smaller scale. In order to maintain the same amount of pressure vs a car with no pre-turbo exhaust leak, your turbo will have to work much harder (higher RPM shaft speeds) to maintain the same amount of boost as the other guy. In the long run, you'll overwork the turbo which will lead to premature turbo failure. I'd replace the gasket if I were you.

And for your vacuum issue, I'd do a boost leak test.

You're confusing a boost leak with an exhaust leak. Exhaust leaks make the turbine spin slower, not faster.

 

[tay97gst]

Check the downpipe connection to the o2 housing. I actually just replaced a gasket there and it was pretty damn simple. Just need to be under the car is the only problem.

 

[Alucards_blood]

You're confusing a boost leak with an exhaust leak. Exhaust leaks make the turbine spin slower, not faster.

Yeah, youre right about the pre-turbo exhaust leak slowing down spool. Had to think about what I was typing. Even so, wouldn't the turbo still need to work harder to maintain the same amount of pressure as a car without a leak?

 

[And_44]

It's the amount of air (exhaust) flowing past the turbo that makes it work. If your leaking exhaust before the turbine your not working it to its full efficiency. Your just diverting the flow and it's being wasted. Your turbo will still spool the 15lbs (example) but at a much higher exhaust output (higher rpm). The turbo will still spin just as fast. But yes you will be asking more out of your engine to make up for the lost volume of exhaust which is leaking before the turbine.

The over working your turbo is from BOOST leaks which are in the intake. Your turbo will have to spin faster to fill the intake to the requested 15psi(example) if it's leaking out in the intake somewhere. If your intake is sealed correctly and it hits the 15psi your wastegate opens and diverts the exhaust past the turbine telling your turbo congrats you made it to 15 you don't need to work so hard.

In a perfect world there should be no intake leaks and no exhaust leaks prior to the o2 sensor. Should all be sealed between maf sensor (stock location) and o2 sensor as close to air tight as possible.

 

[upgrading_86]

I started taking the exhaust manifold off but before I was having trouble going up small hills it proggresively got worse and everything everyone is saying about higher rpm makes since cause I was staring to think my clutch was slipping I guess ill change all the turbo gaskets and get back to you guys thanks for the info ill repost with a pic of what gaskets ill be changing just to be sure

 

[upgrading_86]

Leak fixed still kinda sluggish floor it and doesn't get up on rpm fast enough

 

[dsmornothing]

When is the last time your plugs were replaced? Also could be an O2 sensor...

 

[upgrading_86]

Yesterday to be honest plugs looked on the rich side also changed wires both NGK 8mm sites and forgot what number plug but o2 sensor you say could you explain why please ?

 

[And_44]

Bad o2 sensor would make you run automatically rich as a safety default. You'll foul plugs quicker and acceleration will be hurt slightly as you have more fuel to air and bogging down your combustion process with excess fuel.

Can check your o2 sensor with a data logger (voltage output, fluctuating at idle, ect)

 

[AllWheelRS]

Have you done a boost leak test?