"I have a brand new 3.0L MerCr
"I have a brand new 3.0L MerCruiser Alpha engine. Idle was smooth on tech ride at the dealer, but we took it out yesterday for the first time and when idling, it's nice and smooth for about 30 seconds or so, then it shakes violently for a few seconds, then goes back to smooth. Then after a minute or so it shakes again. We think we heard a hissing sound coming from the engine compartment - we thought it might be a vacuum leak, but we could not determine where it was coming from."
"I have a brand new 3.0L MerCruiser Alpha engine. Idle was smooth on tech ride at the dealer, but we took it out yesterday for the first time and when idling, it's nice and smooth for about 30 seconds or so, then it shakes violently for a few seconds, then goes back to smooth. Then after a minute or so it shakes again. We think we heard a hissing sound coming from the engine compartment - we thought it might be a vacuum leak, but we could not determine where it was coming from."