Chevy 350 Blown HG at oil galley?

[Junior Samples]

thats why for me i just cant stress enough that keyboard diags can burn me, if its in front of me i go through the motions and can isolate the problem, i get on and try and help if i can but sometimes all i can do is just sit back and take another swig of my diet coke...lol

 

[acoen]

i just dont think a leaking intake gasket although on #7 cylinder would pull that much oil from the valley if its smokin like a james bond mobile, i try to picture oil weaping up and along you take the angle in which the intake sits on the head, crankcase is vented so its not going to pull oil up to underside of intake gasket into port to be burnt.

But then I see who it is aka Chuck L and having read his posts on other threads and knowing who he is etc i start to second guess myself cause it really doesnt matter how much i know, i think other guys in here have forgotten more then i'll ever learn

All i know is a vacuum gauge will point one in the right direction everytime and if the intake has any leak then the gauge will show, and valves and rings on and on

clogged pcv will cause crankcase to volcano out as well

Checked the PCV and it was perfect no obstruction. I also have no other blowby. Everything is exiting the exhaust and get worse with RPM.

I'm with you, I sound ingorant compared to anyone on this post....I try to learn something new every day. I feel good I have the experts stumped...This one is puzzling me.

 

[Junior Samples]

have you put a vac gauge on it yet? perfect is of course 17 to 22 inches steady depending on elevation

 

[acoen]

thats why for me i just cant stress enough that keyboard diags can burn me, if its in front of me i go through the motions and can isolate the problem, i get on and try and help if i can but sometimes all i can do is just sit back and take another swig of my diet coke...lol

Yep, I can relate. You know, at first I thought the oil was being sucked, due the fact there is so much....Where can it be sucked in from, that is why I thought HG. Then I did a comp test with resonable results. No blow by on the upper end of the motor. No heavy miss, good idle and power, just smoke. Like it is being sucked or pulled in....ie valve seal or guide problem. Who knows the guy may have knurrled the guides to a point that the seals don't seal....I don't know...But I will tomorrow. Leak down test is next.

 

[acoen]

have you put a vac gauge on it yet? perfect is of course 17 to 22 inches steady depending on elevation

I can do that tonight easily I have a vacuum gauge....17-22 is good anything less will point to valve train or rings correct?

 

[Junior Samples]

yeah they have diff readings on it..like low vac 15 inches and steady..um 17 inch then drop blah blah...if you google vac gauge readings..i think theres a couple of sites that have little animations that show what to look for, off the top of my head and all my books are in garage i cant say
How to Use and Interpret a Vacuum Gauge

better link

 

[acoen]

yeah they have diff readings on it..like low vac 15 inches and steady..um 17 inch then drop blah blah...if you google vac gauge readings..i think theres a couple of sites that have little animations that show what to look for, off the top of my head and all my books are in garage i cant say
How to Use and Interpret a Vacuum Gauge

better link

Thanks my friend....

 

[acoen]

yeah they have diff readings on it..like low vac 15 inches and steady..um 17 inch then drop blah blah...if you google vac gauge readings..i think theres a couple of sites that have little animations that show what to look for, off the top of my head and all my books are in garage i cant say
How to Use and Interpret a Vacuum Gauge

better link

Now that should be a sticky somewhere...That is an awesome site. I will put my gauge to work tomorrow. Thanks again guys.

Aaron

 

[gofstbuick]

Intake gasket..

Like Chuck says, did you check that intake gasket? If you're not trusting the guy who assembled it, the intake gasket assembly can very easily be overlooked. Is this an aluminum or cast iron intake? Because the torque sequence starts from the outside in on aluminum and inside out on cast iron.

 

[acoen]

Like Chuck says, did you check that intake gasket? If you're not trusting the guy who assembled it, the intake gasket assembly can very easily be overlooked. Is this an aluminum or cast iron intake? Because the torque sequence starts from the outside in on aluminum and inside out on cast iron.

Joe,

How could the intake gasket cause oil to be sucked into the cylinder? From the valley pan? That is a thought! It could be pulled right on in....I will check that too...Its gotta be something simple...I think the intake is cast, throttle body injected.

Thanks Joe

 

[imjoesnuffy]

Intake gasket...

+1

Identical symptoms on a 73 Camaro I had.

This was after having the heads rebuilt. Stripped a bolt hole reinstalling the intake.

 

[Junior Samples]

Is this an aluminum or cast iron intake? Because the torque sequence starts from the outside in on aluminum and inside out on cast iron.

you always pick a number one hole in the middle on pass side behind carb if you happen to be standing there and work your way out, Alum.. you also need to start from the middle and work outside crisscrossing 30# iron to iron, 20 ft #s alum to iron and 15# alum to alum

that intake he has should be alum, and it is #7 which could raise the possibility with intake leak but it would be leaking like a siv out the back as well

you think of it this way, the motor sits at a slight angle tilting backwards and the oil from the pushrods collects and drains back to the drainhole next to #7 if mr shade tree put the head back together and forgot to install a seal.... or the guide is leaking.

in the end he got the truck from a friend who had someone fix it who was not much of a mechanic so that right there opens it up for anything, hell he could have forgot to remove his beer from the valley when he slapped the intake on..lol

 

[gofstbuick]

Joe,

How could the intake gasket cause oil to be sucked into the cylinder? From the valley pan? That is a thought! It could be pulled right on in....I will check that too...Its gotta be something simple...I think the intake is cast, throttle body injected.

Thanks Joe

SBC uses an intake gasket, not a valley pan, so it can very easily suck oil from a slipped gasket.

 

[gofstbuick]

that intake he has should be alum,

Because it is an aluminum intake you begin from the outside and work your way in, because of the way the aluminum vs cast iron materials flex. Look in your service manual and you'll find that the torque sequence for SBC with aluminum is different from SBC with cast iron intake.

 

[Junior Samples]

the vortec intakes got rid of the 4 middle holes but you still start from your inside bolt holes and work your way out... @ 11ft#s on the vortecs but hes not running a vortec intake anyway

so if its iron then you start from the middle and work your way out and if its alum you start from the outside and work your way in?

so same with heads eh? alum heads on a chevy? id want to start from the outside and work my way in? because its alum?

wellllll lets hope he gets that oil leak takin care of anyway

 

[gofstbuick]

the vortec intakes got rid of the 4 middle holes but you still start from your inside bolt holes and work your way out... @ 11ft#s on the vortecs but hes not running a vortec intake anyway

so if its iron then you start from the middle and work your way out and if its alum you start from the outside and work your way in?

so same with heads eh? alum heads on a chevy? id want to start from the outside and work my way in? because its alum?

wellllll lets hope he gets that oil leak takin care of anyway

Did I miss something? I don't recall Aceon saying anything about vortec, nor do I recall an 1989 chevy truck being equipped with a vortec v8.

Not cylinder heads, just intake manifold torque.

 

[acoen]

Good replys guys, I'm going out to run a vacuum and leak down....i should know something soon.

 

[acoen]

Did I miss something? I don't recall Aceon saying anything about vortec, nor do I recall an 1989 chevy truck being equipped with a vortec v8.

Not cylinder heads, just intake manifold torque.

Nope, not vortex just a TBI intake...gut feeling is valve seal, but the intake is an easy fix too. I will keep you posted.

Aaron

 

[Junior Samples]

i stated he wasnt running a vortec intake which hadnt come out then but i used that intake as reference to the fact that there are no middle bolt holes on them intakes they only have 8 but you still torque em down from the middle out. I dont know what shop manual your looking at, cause i just got done poking around in some of my old GM shop manuals for vettes and nothing said about that cause i woulda gladly came back and fired up my grill for some crow on the barbie

Easy mistake thats fine im not here to split hairs and would like to try and remain humble but im tellin ya man, a small block chevy alum intake you never tighten the intake down from the outside and work your way in.. you just dont, ive never heard of it , ive never done it and if its some old secret hod rodders trick from the west coast then id love to hear it.

Problem here is he has an oil leak getting into his #7 cylinder, rule of thumb when burning oil. If it puffs out smoke when starting after it sits or upon heavy deceleration. You would have bad valve seals or guides or both. When puffing smoke upon acceleration. You probably have bad piston rings or scorched cylinder walls or all of the above.

Could it be intake leak from bottom of gasket pulling oil up from valley? yeah i'll go with that.

 

[acoen]

No worries guys...I did the vacuum test today 3 times....Nothing out of the ordinary 22-23hg vacuum steady. goes to near zero on acc and 26-28hg on decelleration. I did look at the valve seals....I replaced the intake seal...didn't look bad, the exhaust had an umbrella seal....Can I use an intake seal on the exhaust too or will the heat kill it. I pulled the intake. The intake runner for cylinder 7 and 8 was slick with a thin film of oil. intake bolts were not torqued in any regular fashion....some very tight others loose especially around 5 and 6. Oh aluminum intake. I will finish tomorrow.

I do have a leak once I pump up cylinder 7 the valve is leaking, could be carbon build up from the oil consumption. I willl take care of that with some top engine cleaner....Also TBI gasket in poor condition, but that will be fixed to. everything else looks good.

I will retorque the head since it has been about 5k miles since the valve job.