This oil just recently appeared, and if i wipe it up it comes right back, the oil on the dipstick is still perfect, i can go 3000 miles easy without having to add a drop. the oil doesn't really flow, but if i get somethign to obsorb it, it comes right back, but yet doesn't flow any more. a couple of yall had ideas that it could be from the lifter valley filling with oil, wich is probably right, but i just wanted to post the pics.




(above image) This shows the oil on the actual thermostat housing. how did it get here.

my first post was here for more info.
https://www.thirdgen.org/messgboard/...ML/003990.html

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88' GTA 350 MODS---> air foil, K&N, Shift Kit, 180* therm, TB bypass

[This message has been edited by breathment (edited August 18, 2001).]

[This message has been edited by breathment (edited August 18, 2001).]

 

maybe you have an intake manifold gasket that's leaking really slow? or valve cover gasket? I'd try changing the valve cover gasket, those are easy... but I can't think of anywhere else..

 

i agree with what gm tech said. maybe your bolts are where the oil is seeping by.you can fix by taking out 1 bolt at a time and put a small amount of rtv on threads and screw it back in. cheap fix. or makes sure they are good/ change your valve cover gaskets.and check to see if bolts are tight. also...is there oil anywheres else? on the under side of the hood? or anything? if not that whole front cover leak theory goes out the window. but i would start by atleast trying to tighted intake bolts (where oil is) just a tad bit/make sure they are not loose.

http://people.ne.mediaone.net/gdm

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87 z28 bowtie aluminum 420small block dry sump crower lt. wt. knife edged crank oliver lt wt rods brodix track 1's super ram intake slp 1 3/4 headers accel dfi art carr 700 r4 3.42 gears ssm sub frame/ladder bars.....other parts on the way ,soon to be finished!! couple more weeks!!!

 

it looks like that is the only place where there is oil at. its not a bad leak, but im worried about water getting in there, if i ever washed off the engine etc.

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88' GTA 350 MODS---> air foil, K&N, Shift Kit, 180* therm, TB bypass

 

Check your intake manifold bolts for proper torque. On my 86 the torque is 40~45#.

You may not can get to all of them.... at the very least check the 4 center ones you CAN get to. Mine were so loose I could turn them with a 1/4 inch drive socket.

 

This is a very common 'problem' on SBCs, like GMtech said in the first post, it's from oil vapor condensing and riding the threads on the intake bolts out of the lifter valley. Remember capillary action in physics/biology class.

The soplution is as stated in the other post, coat the threads w/ some THREAD SEALER. Do NOT use RTV. While it will work to seal the threads, you might just end up stripping the holes. Silicone does weird things when it is compressed in threads, screwing up the feel/torque reading. I personally whacked a couple bolt holes in the heads the first time i had the intake off my 85 using RTV to seal them. Considering a tube of thread sealer is a couple bucks and is right next to the RTV at the parts store, do yourself a favor and just use the right stuff.

 

Well you can try to fix the bolts but that will only be a stop-gap. The manifold will have lifted by now and the intake gasket is on it's way out.. Are you getting any surging under hard throttle ? How about poor idle ? Tell-tale signs of a fried gasket.

I have similar leaks on my manifold although they are inboard towards the center. I plan to pull the manifold and replace the gasket. My advice to myself when I do the job is to be sure to RTV sealant the gasket as well as the end rails, and apply thread seal to the bolts. BTW: GM does not apply sealant to the intake gasket from the factory. They still don't (check out the LT1 and LS1 boards and see how many of them are griping at leaking intakes).

My .02 cents worth.

 

I'd just say the hell with it, remove the lower intake, port it (stock, right?), replace the gaskets(probably original?) replace the valvecover gaskets, and this'll be a good oportunity to check your valvetrain and stop that leak. And you gain a few HP! If you do pull the lower intake, don't use the cheap 'china wall' gaskets they give you, put a liberal bead of silicone on the front and back of the block, abit under and over the edge of the intake gasket, and set it down. This seals ALOT better and the last time I checked GM reccomends it as well. Don't wipe off the excess !

 

It sure looks like oil, but could it possibly be coolant that is turning black from heat? It sounds as if the only places this is appearing is next to water passages. Corrosion almost invariably happens around water passages when you have aluminum intakes. This is due to dissimilar metals (aluminum manifold - iron heads/iron bolts).

Just another possibility.