Big block oil consumption problem with pics
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 793
Likes: 1
From: Houston Texas
Big block oil consumption problem with pics
Need a second opinion.
Motor was overhauled a year ago. Stock stuff, new everything except castings. This includes guides, valves and seals. Iron guides but I'm not sure what the seals are (last two pics are of the seals). Engine has about 800 miles and has not stopped using oil. About a quart per 500 I'd say. No noticeable smoke when driving and none on start-up. Engine was OH'd before I purchased the car, shop didn't log the type of stem seals on the invoices I have.
I brought home a bore-scope from my maintenance department (not automotive maintenance) to look inside the intake runners hoping to find oil in them. No such luck. Stuck the camera down in the heads to peek at the intake valves and this is what I found. My hope is this burned oil buildup is not bad enough to warrant removing the heads and I can just replace the seals. IF that's the problem. What thinks you??
Also took a shot of the #1 piston crown and also the "seals" on the valve stems. My feeling is the engine shop installed some kind of high-tech seal that either doesn't work properly or was improperly installed. If it is the guide seals, can you still get the umbrellas that GM used? If so, who makes the best?
Thanks!
Motor was overhauled a year ago. Stock stuff, new everything except castings. This includes guides, valves and seals. Iron guides but I'm not sure what the seals are (last two pics are of the seals). Engine has about 800 miles and has not stopped using oil. About a quart per 500 I'd say. No noticeable smoke when driving and none on start-up. Engine was OH'd before I purchased the car, shop didn't log the type of stem seals on the invoices I have.
I brought home a bore-scope from my maintenance department (not automotive maintenance) to look inside the intake runners hoping to find oil in them. No such luck. Stuck the camera down in the heads to peek at the intake valves and this is what I found. My hope is this burned oil buildup is not bad enough to warrant removing the heads and I can just replace the seals. IF that's the problem. What thinks you??
Also took a shot of the #1 piston crown and also the "seals" on the valve stems. My feeling is the engine shop installed some kind of high-tech seal that either doesn't work properly or was improperly installed. If it is the guide seals, can you still get the umbrellas that GM used? If so, who makes the best?
Thanks!
Advanced
Joined: Jun 2008
Posts: 67
Likes: 0
It looks like someone installed positive control (PC) seals on the valves. Is the main body of the seal rubber with a round tension spring at the base of the seal?
PC seals are designed to fit tightly over the valve guide which needs to be machined to accept these type of seals. If these seals are allowed to move up and down with the valve they will allow excessive oil to reach the guide; thus the engine will smoke and use excessive amounts of oil.
Norm
PC seals are designed to fit tightly over the valve guide which needs to be machined to accept these type of seals. If these seals are allowed to move up and down with the valve they will allow excessive oil to reach the guide; thus the engine will smoke and use excessive amounts of oil.
Norm
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Do you have a PCV valve set-up on your engine? If so, is it working properly? Do you have a way for 'incoming' air to enter the block?
If the PCV valve is stuck 'open', or if your PCV valve is not baffled in the valve covers, you could get a lot of blow-by oil getting sucked into the engine and cause just what you are seeing.
Good luck on finding the cause.
If the PCV valve is stuck 'open', or if your PCV valve is not baffled in the valve covers, you could get a lot of blow-by oil getting sucked into the engine and cause just what you are seeing.
Good luck on finding the cause.
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 793
Likes: 1
From: Houston Texas
Do you have a PCV valve set-up on your engine? If so, is it working properly? Do you have a way for 'incoming' air to enter the block?
If the PCV valve is stuck 'open', or if your PCV valve is not baffled in the valve covers, you could get a lot of blow-by oil getting sucked into the engine and cause just what you are seeing.
Good luck on finding the cause.
If the PCV valve is stuck 'open', or if your PCV valve is not baffled in the valve covers, you could get a lot of blow-by oil getting sucked into the engine and cause just what you are seeing.
Good luck on finding the cause.
The problem must lay with guide seals, ring seating or intake manifold seal. I think it's the guide seals. I looked at the runners with the bore-scope, and compression is up.
Melting Slicks
Joined: Jul 2001
Posts: 2,609
Likes: 12
From: Massapequa Park NY
You need to find out exactly what was done to the heads, were new valve guides installed, new valves, etc. Looks exactly like the valves in my Mustang when I rebuilt the engine the first time. New guides, positive seals, springs, etc. But the machine shop said the valves were good so they were reused. Fought an excessive oil consumption problem for a long time until I pulled the heads for a third time & broght them to a different machine shop. Valves were tapered & wiped out the guides in short order. New guides, valves, seals & a fresh rebuild and everything has been fine for the past 10 years.
Jim
Jim
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Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
several issues come to mind here but if you want to talk seals, those are teflon positive types and if not installed properly, will not stop any oil...your guides must be in tolerance to use them and you must protect the seal itself when installing so as not to cut them on the keeper rings of the valve stems, if this is done, the seals are rendered useless.....good luck....
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 793
Likes: 1
From: Houston Texas
several issues come to mind here but if you want to talk seals, those are teflon positive types and if not installed properly, will not stop any oil...your guides must be in tolerance to use them and you must protect the seal itself when installing so as not to cut them on the keeper rings of the valve stems, if this is done, the seals are rendered useless.....good luck....
The invoice shows new guides and valves. The shop has a history of building big blocks since the 60's. However, the old man that owns it is not very helpful, says he can't recall the specifics of the guide material. They build a lot of engines and this one was done January of '09. From appearances the parts certainly do look new though. What should I do first, pull springs and check the seals? How do I determine if I can put original style GM seals back? I never had a problem with those back in the day.
Le Mans Master
Joined: Nov 2006
Posts: 5,262
Likes: 283
From: I'd like to propose a toast... to internal combustion and wind in the face.
When I rebuilt my 454 I had kind of a similiar situation. The car smoked like crazy. A friend suggested I remove the intake and look for oil on top of the intake valves and that's exactly what I found. The oil was literaly pooled up on top of some of the closed intake valves. Feeling strongly that the oil could only come from leaking intake gaskets or leaking valve stem seals, I replaced them both and the smoking completely ceased. Of course I had to perform the entire routine again after the camshaft was assassinated but that's another story...
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 793
Likes: 1
From: Houston Texas
Are those valve springs doubles or are they simply an outer spring with an inner damper? If the springs are doubles then there probably isn't enough room to install umbrella seals as the seals will rub or catch on the inner spring and just ride up and down. That's what mine did before I switched back to valve springs with dampers. Also, I can't comment on whether or not there is enough valve guide material left to hold an umbrella seal now that the guides have been machined for postive stem seals.
When I rebuilt my 454 I had kind of a similiar situation. The car smoked like crazy. A friend suggested I remove the intake and look for oil on top of the intake valves and that's exactly what I found. The oil was literaly pooled up on top of some of the closed intake valves. Feeling strongly that the oil could only come from leaking intake gaskets or leaking valve stem seals, I replaced them both and the smoking completely ceased. Of course I had to perform the entire routine again after the camshaft was assassinated but that's another story...
When I rebuilt my 454 I had kind of a similiar situation. The car smoked like crazy. A friend suggested I remove the intake and look for oil on top of the intake valves and that's exactly what I found. The oil was literaly pooled up on top of some of the closed intake valves. Feeling strongly that the oil could only come from leaking intake gaskets or leaking valve stem seals, I replaced them both and the smoking completely ceased. Of course I had to perform the entire routine again after the camshaft was assassinated but that's another story...
Le Mans Master
Joined: Nov 2006
Posts: 5,262
Likes: 283
From: I'd like to propose a toast... to internal combustion and wind in the face.
Well I guess I'm about to get the compressor hooked up and pull a valve spring to find out. From what you say, to install teflon seals means machining the guides and therefore the GM seals are out unless I pull the heads and have new guides installed. If I install new teflon seals properly can I expect them to work as well as the GM's?
My money is on a leaking intake. I just can't imagine that much oil traveling down past new valve stem seals.
You know, everyone has their preferences and when it comes to intake gaskets and my preference is Mr. Gasket brand intake gaskets. The Fel-Pros I intalled on my 454 leaked like a sieve. Now I realize that Fel-Pro gaskets are some of the most widely accepted gaskets, all I'm saying is the Mr. Gaskets worked for me when the Fel-Pros did not. Maybe (okay, probably) the failure of the Fel-Pros was in improper installation on my part, but that still doesn't change my success rate with the Mr. Gaskets. The Mr. Gaskets are nice and thick and I just like'm.
Someone please chime in and correct me if I've given any poor or incorrect advise/information.
Last edited by mudbone64; Oct 11, 2010 at 01:06 PM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If it were me, I would pull the heads and take them back to the shop for inspection and repair [if necessary]. That will also allow you to check out the head gaskets and intake gaskets. So, the only thing left...if that does not reveal the problem...are the rings. Here's hoping you don't have to go that far.
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 793
Likes: 1
From: Houston Texas
OK, Thanks guys. Here is some new info and questions.
I pulled the intake and all runners in the heads were wet with oil residue.
The spring are a large wire spring/flat damper/small wire spring design.
If the seals are leaking I assume that the exhaust valves should have the same buildup that the intakes do. Correct? If not, then that's confirmation of a leaking intake gasket?
Mudbone64, I looked at the MR. Gasket intake sets on-line. Are you referring to the .060 Ultra Seal set?
When the new gaskets go back on do you use any sealant around the water jackets?
I am trying not to remove the heads or pull springs unless the detective work forces me to.
I pulled the intake and all runners in the heads were wet with oil residue.
The spring are a large wire spring/flat damper/small wire spring design.
If the seals are leaking I assume that the exhaust valves should have the same buildup that the intakes do. Correct? If not, then that's confirmation of a leaking intake gasket?
Mudbone64, I looked at the MR. Gasket intake sets on-line. Are you referring to the .060 Ultra Seal set?
When the new gaskets go back on do you use any sealant around the water jackets?
I am trying not to remove the heads or pull springs unless the detective work forces me to.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Did your mechanic deck the cylinder heads and/or mill any of the intake manifold or head faces? If so, there might be an alignment problem with getting the intake to mesh correctly with the heads and block rails (valley ends). Whenever you decide to reassemble it, install the rail seals and intake gaskets dry (no sealant) then dry-fit the intake manifold to see if you have any gaps [which would indicate a poor fit between the components]. If you find a problem, you will have to purchase thicker gaskets/seals as necessary to get a good seal on those surfaces. If that's the problem, you should "bill" your engine rebuilder for those costs, since he should have done it right in the first place.