here is a picture of my engine


there is two small black vaccume caps on top of the uim near the bolts that hold the uim to the lim (straight above the turbo), I have blasted the caps off three time this week when I get hard on the boost. The one on the left all three times but I have cracked the right one a few time as well.

Questions,
Why is this happening ?
What exactly do these vacumme nipple control or do as their job for the engine ? I have seen some routing the one of the left to the wastegate ??
What is the better fix I could cap these with then the little rubber caps I have ?
When these come off, is there a potential harm I could do to the engine ? If I'm cruising I will not notice until the next time I nuetral it, the idle will be 200rpm higher then I have the engine set to. This allows me to know exactly what and when it happened but in the between time I don't wanna harm the engine ?

Thanks for the help all! I'm learning alot from this engine and I appreciate members help

 

Most people run lines to 1 of those to measure boost the other usually goes to your bov to keep it closed under boost. They both do the same thing measure pressure really. If they come off you are just venting air like if a IC coupler broke. I would put a zip tie or hose clamp on the nipple covers to keep them in place.

 

My car, the left one (back on my pic) runs into my car for my boost gauge. The right one (front my pic) goes to my bov.

 

Option 1: take a vacuum line and connect the two nipples. Zip-tie the vacuum line to keep it secure

Option 2: get some good EPDM caps and use them instead of cheap neoprene caps from the local store. The neoprene caps don't hold up under heavy pressure and high temps.

Dave