jac113

iTrader: (4)

hey guys and if there be any gals,
I just installed new intake gaskets this past Friday because of a leaky rear seal. So I get everything torqued down and I do onelast check to make sure everything is everything and that's when I saw a line of silicone hanging out the rear. I figured it was just overflow but when I looked closer I saw some of the block in between the silicone and the intake meaning no silicone under the intake.

Is this even possible unless I somehow scraped some silicone aside during the install. I lined up the silicon bead leading up to the intake gasket but i have about 1/8" outside of the intake. I thought the intake would mount flush to the rear of the block?

So if I have to take it off and reseal I will, but I wonder if I can I reuse the same gasket it without any leaks. I torqued it down to 35 '-lb but have not turned it over.

thanks

jac113

iTrader: (4)

gettin' alot of views so i thought i'd follow up. I took the intake back off and the back wall of the block varies in thickness especially on the driver side of the distributor plus the manifol does no mount flush to the rear of the block. It only actually covers half of the rear wall especially when you get close to the oil pressure sensor port. I ended up buying new gaskets and putting black silicone on the water ports. Torqued to 35 '-lbs in 2 steps and no noticeable leaks yet.

hope nobody makes my mistake. It's kind of easy to do if you can't see where the intake rests on the rear wall.

hydrolic144

iTrader: (2)

I made this same mistake when I first put my engine back together. And did't use silicone on the water ports. Had leaks from all corners. Glad you got it all back together though. As soon as that water gets into the intake, you'll see a leak from somewhere if it's not right, even cold. So doubt anything will come about.

jac113

iTrader: (4)

cool, i'm getting a couple of drops but I think I was gettin' that before the gasket job too, probly the oil pan gasket.

thx hydro144

jac113

iTrader: (4)

Hey guys,
I thought I put this one to rest but it came back to haunt me. I've been having major oil leak issues. I say major because over a short amount of drive time the oil has managed to get all over the cats, tranny and exhaust pipe. I've recently done a couple of things like pan gasket and intake manifold gasket(this post) so wasn't sure where the oil was coming from. I finally get a chance last night to check the dizz seal and give the oil pressure plug another shot and confirmed that the problem was bigger. The dizz seal was seaping but not leaking out. The oil plug was leaking so I doubled up on the teflon tape BUT the the oil trail really didn't get heavy until I ran my hands under the heads. The back of the block(rear of intake manifold area) was oily but it wasn't until I felt under the head/intake joint that it got sludgy on BOTH sides.

Question: before I get too deep into thinking about yanking the block for a rebuild, in case the heads need to come off, I want to make sure that I cant fix the leak by just removing the intake and sealing the intake/head joint better. I read somewhere on here where a guy was having the same problem but can't remember the solution. I can't imagine having to take off the head to put sealant somewhere that I wouldn't be able to get too by just taking off intake???

big problem is, besides losing oil, the oil burns when pipes get hot and I put on a smoke show from outside and inside the car,lol. Not something I try to do btw, more afraid of my B4C going up in flames actually.

thanks 3rdgeners.

305sbc

iTrader: (3)

I recently repaired a friend's engine that had a similar problem.
It is a 200,000+ mile TBI 350 that was producing more blow-by than the PCV system could handle. The resulting internal crankcase pressure was enough to push past several places in the already aged and weak gaskets of the intake and oil pan. I had to pull both the intake and pan to re-seal, but the real solution was to properly vent the crankcase to match requirements.
I added dual PCV valves (one per valve-cover), and an extra vent from the lifter valley - via the front of the intake manifold.

I also wasn't thrilled with the lack of good sealing surface between the intake manifold and the block, especially around the rear of the block and distributor. I used epoxy to build up the sealing surface area to increase the chances of keeping this thing sealed up. Some people prefer to use weld for this, but I don't own a TIG, and thought this would be satisfactory.
I drilled and tapped a hole for the extra vent and fabbed up a screened baffle for underneath the vent to keep liquid oil out.
I used Permatex high-temp red RTV on all, as I have found it to be stronger and more durable than most sealers.
I used plenty of sealer in this case, as well as washers under all the bolts to distribute load.
There are some photos of the job showing the epoxy reinforcement here:
http://s702.photobucket.com/albums/w...uck%20project/

The engine is used as a business work truck and has been working for a few months with no problems or leaks since the changes.

jac113

iTrader: (4)

Thanks 305 for the write up, I never considered excessive blow by and honestly I don't fully understand it. I'm assuming it's the compression that gets past the rings on a tired engine. Whatever the case, my main concern was if there was a possibility that the leak could be coming from the head itself. A mechanic told me unless you have oil in your coolant it's probably not the head. He recommended using an A/C dye to find the leak. I'm trying to remember how much sealant I used at the head/intake gasket joint and probably wasn't enough. Going to pressure wash the rear of the block and undercarriage while i'm at it to confirm where the leak is coming from. If I see the same oil buildup then will assume its the intake/head joint and plan for another intake gasket r/r....fun.

thanks