Just got an 06 gg mr with 120k miles about two months ago. The car was well maintained with all service intervals done on time. Just this past week I noticed I was losing boost and power. So I did a boost leak test only to find out that when the throttle body was wide open I'd lose pressure in the spring area of the throttle body. Do I have to change the whole thing or is there a seal that I can change?

 

Search mil spec seals. ~$20 and better than original. STM has them usually (and I think their own brand too), not sure who else.

 

^^^^^ that. They are like 26 bucks or something.

 

Thanks guys. I'm jumping on this tomorrow.

 

Do you need to change the tb gasket once you remove it?

 

im having trouble understanding why u have the throttle body wide open for while doing the boost leak test.

u dont need to change the gasket but if u have one u might as well since its a pita removing the tb anyways.

 

multipost edit.

 

Because the throttle body has a rotating shaft with a seal around it that may not hold in all positions. Rotate the throttle plate opened to check it properly.

If you had an axle seal that only leaked when the axle was turning, you wouldn't call it good would you?

 

i c.

 

Thanks guys. I got it. Thanks to Shaun @ awd motorsports.

One question though. I have the stock mr boost gauge and boost peaks a little over 1 bar and tapers to 1 bar. I know it suppose to be more than that. Is the stock boost gauge accurate? I did do my boost leak test over and I got the leak. Am I missing something. Ordering a proper boost gauge as we speak.

 

I wouldn't sweat over it until your new gauge reads wrong, since you have one coming already anyway. Those rally pack gauges were horribly inaccurate. People here often profess their love for them, but the truth is I threw away a set of those things a week sometimes. They just weren't reliable long term.
If the new gauge reads low too, then look into it.

 

 

Got another question. Was doing some more boost leak test when I discovered that if I hold my thumb on the valve cover breather for 30 sec or more, a burst of air comes out as if it builds pressure slowly. Is this suppose to happen?