So just wanna get some help.
Not too long ago, I swapped in my manual transmisssion, and when I did I had the motor out and did the plenum.

I used dormans kit, and had a Cnc cut 1/4" aluminum plate I bought off eBay. I torqued down everything correctly and have had no problems.

Now i have a problem. One day when I went to pick up tires from another store for work, I noticed when it was idling a constant whine, kinda like the high pitched whine that come from Chevy fuel pumps. I drive it back to work and then home once the day was over, and it was still there. Same pitch, nothing changed it, not getting on it, not speed. It sounded like it was coming from the center of the intake. I took off the air filter and didn't notice anything weird, and then I started it took off the engine breather and it had a lot of vacuum, so I covered it, and the whine almost completely when away. Now I know it's supposed to have vacuum, but how much?

I then checked my oil and it was about 3 qts low, not even close to the oil change. Usually only drinks 1/2 quart every 6000. So I filled it and drove it, whine got way quieter, I can barley hear it now. I checked the oil today and was not even on the stick so I gotta fill it up again. But the whole situation happened 2 weeks ago, so I'm not sure why. It's just all of a sudden it Happens.

Ever since the whineing started I've had a high idle at like 1000, and it used to idle around 500-700. It's like it has a massive vac leak.

I'm going to look down the tb later today, but I kinda want to get some of your opinions. Im suspecting my plenum went and I'm super pissed if it did.

I just want to get some opinions and help, I know the sticky at the top of the page, but this is just odd, concerning the whining, everything else leads to the plenum.

 

Whining may be air flowing thru a blown gasket.......

High crankcase vacuum could be the plenum, or the intake gaskets for that matter. Extremely high oil consumption also points in that direction. (if you don't have any evidence of major leaks.)

Have a look down the TB, see what you see. If it's clean, probably just an intake gasket.

Thinking even further, what about the PCV valve? Is it stuck open?

Seems most folks recommend 8-14 inchs of Hg crankcase vacuum. (at idle.) That number *should* go down as the throttle opens, as, at WOT, there is ZERO vacuum in the intake.

 

Well I'll check for Oil in the plenum.

I replaced the pcv when I did the plenum.

I used the dorman intake gaskets, so I wouldn't be surprised. I know I had the intake cleaned real good with all the mating surfaces, but im not sure how I did on the heads. I put rtv around all the ports like reccomend.

 

I only use RTV around the coolant passages, and a dab in the corners where the intake gaskets meet the valley seals... nothing anywhere else.

 

I have no idea how in the world this could have happened so fast, but my plenum is gone.

Carnage pics:





That little stub is the torn gasket

How do you think this could have happened? I used a 1/4 think plate, like the Hughes plate, but I bought it off eBay, and then I torqued it down. I'm pissed i have to do this again but I just wanna know why it happened.

 

I think those bolts get torqued to like 72 INCH pounds..... if they were overtorqued, the gasket would squeeze right out.

Make sure you use a GOOD quality gasket. (fel-pro.)

 

Yeah I know for sure I did inch pounds for sure, but I didn't use fepro, I used the doorman kit. I know people have used that and worked good, but would that be the likely problem?

 

Yeah, I try and avoid most doorman products..... Their door hinge pin kits seem to be ok, but, their sensors, gaskets, and pretty much anything electronic suck.

 

Well I ordered the kit again since it comes with al, the bolts and such, and I also ordered a separate gasket kit from malhe as well.

 

Not replacing the plate are you? Don't really need too...