+1, like I've said a 1000 times, that test is a waste of time.

 

I was looking for somebody who documented a false negative on that crank vacuum test, and at least one has experience with that, above. Conceivably, a small leak could be intermittent, perhaps because of oil clogging of the damaged area. Or, perhaps the volume of air moving across the gasket is not enough to overcome the volume of blowby gas produced. In any case, it seems pretty clear that the negative predictive value of that study, in a vehicle with classical signs otherwise, is not perfect. Thanks for the feedback.

 

I got a quick question, can a intake plenum leak cause exterior oil leaks around the oil pan? I'm still kind of new to stuff dealing with the plenum problem. and welcome to DF spelunkerd, I was commented on your plenum video on Youtube, names Alex.

 

A blown plenum won't cause oil leaks around the pan. Valve covers can though, as mine do.

 

Or rather, as all Magnums do. I have yet to see a Magnum without leaking valve covers, much less a LA. Those bolts get loose, they need blue threadlocker, FelPro gasket, and some good torque to keep em tight and leak free.

 

True. I'm always glad to see that I'm not the only one with a overly dirty block due to leaking gaskets. Though they've gotten better since I tightened the bolts and I'm actually driving the truck.

 

I believe the valley gasket across the back edge of the Keg is also a leaker, running oil down the back of the block, and dripping off the bottom of the bellhousing.
Often it gets disturbed during assembly.

 

You know one thing I didn't do when I installed my plenum was use a thread locker on the pan bolts.. They don't torque down that tight.. I wonder if they will rattle loose over time

 

I mean probly not.. The original bolts didn't have thread locker and they were fine from what I could tell anyway..

Just makes ya wonder you know ? 84 inch lbs is not alot

 

SOOOOO I did not read the whole thread but is there not a vacuum kind of test that can be done to check the plenum, like wouldn't crankcase show above average vacuum due to extra air being pulled in through the gap? I am not an expert on how the system works just throwing out an Idea that some one can back up or shoot down with sound mechanical reasoning.