eric951turbo

Questions: could a leaking bov create a vacuum leak?

I've been hunting down my vacuum leak for over a month now... Removed the intake about five times, changed all the hoses etc... Im also experiencing low power on take off, bust under boost the car runs fine.

87 944 C

no, a leaky bov would be a boost leak

a leaky bov has an owl noise to it usually and the car wouldn't boost fully as the bov would struggle to hold the extra air...and create the owl hoot noise

eric951turbo

Well tks and no tks lol, im out of idea on where to look.

divil

I am not sure if the BOV would create a vacuum leak, but the test recommended by most threads I've read is: pull the small vacuum line and see if you can suck air through the fitting. If you can't, it's good. You can test it in seconds without removing anything from the car.

I seem to remember from your other thread you had air leaking during the pressure test. Besides the obvious hoses etc., air can also leak from the air oil separator seals. I am pretty sure that's what made it difficult for me to do the test. I could hear the air coming form that area. I never replaced mine, but even so it doesn't make my car slow off boost. Other things can cause that, so before you drive yourself crazy looking for a vacuum leak, are you sure that's what's causing your issue?

How are your ignition components, spark plugs etc., electrical ground connections (this was the problem in my case)? There are a bunch of things that often cause your issue and are free/cheap/quick to check.

eric951turbo

Thanks divil, everything you mention above as been done, replaced, clean etc...

I strongly suspect my Godzilla **** bov i bought last year from a rennlister.

Car was fine last year when i stored the car... Only thing i did is oil pan gasket, rod bearings, removed and replace timing + balancing belts to fix an oil leak behind the plastic protection for the tb

The other thing i did was build a maf pipe tree to make that Godzilla bov work.

I had to cut my orgianal maf tree to make it fit, so now im stuck i can't reinstall with the old bov

I been having this problem since those mods

87 944 C

what's the car doing?

you said you did timing belt, if it's wrongly timed it can create running issues, especially if the car is chipped where it's already advancing/retarding timing.

eric951turbo

Found it.


Did the intake pressure test again....

1. The missing power low gear problem: clamp at the inter cooler coupler was bad... Had a small leak there. Power is back

2. I still have vacuum leak... The vband on the bov is slightly broken... Small leak there. Found a vibrant vband that i think is gonna fit, will order tomorrow

3. Big leak at the throttle body: will order the kit to fix it


Now my new question: there is a leak, or many at the aos thing in the back.... Prob the 2 red seals... But big job to replace. Could this affect my vacuum pressure or not. It's probably been there forever, had no problems last year