Strange Motor Problem, Oil Consumption

[zrayr]

Originally Posted by YerDugliness

I made the mistake of using full synthetic oil in a Mitsubishi Eclipse from about 1,000 miles on.....the rings never did seat, it used oil all of it's life.................."

many new cars, Corvette's, Porches, etc. leave the factory with full synthetic oil & never burn a drop. Using your logic, they should be using oil as well...... but they don't. No doubt your Mitsubishi Eclipse had problems from the beginning, but I doubt synthetic oil was the cause of them.

Z.

[Excaliber]

I would not assume that ALL engines, particularly after market style engines, will benefit from synthetic oil. In fact, synthetic could be a problem for many of them.

I'm not convinced it's always the best choice for a new car either. Manufacturers have various reasons for using synthetic, sometimes in THEIR best interest, not yours, or the motors.

[wrogers55]

Thanks for all the replies, all good info.

I'm going to go about this one thing at a time.

I changed the oil back to no synthetic 20-50 Castrol and no change in the oil consumption or wispy smoke, oil smell.

Next on the list is to replace the intake gaskets. Considering that the two middle plugs on the passenger side are the only ones showing oil burning, it would seem the intake gasket may be leaking in that area and letting both cylinders suck oil at the same leaking spot. Seems reasonable to me, so I'm going there next.

If not that, then on to the valve stem seals, but really would be strange to have two of them right together go bad at exactly the same time.

Thanks again, lots of help on this board.

[Mohuska]

Wayne,

I would like to hear what the outcome was as I am having exactly the same type of issue. I'm thinking it is either a sloppy valve guide or valve seal.

Let us know what you found...

Mike

[wrogers55]

OK, ready for my next step in solving this oil consumption/smoking.

Intake gasket for the AFR 205 heads and Vic Jr. FI Mass-Flo manifold.

Can anyone help me with part numbers for SCE intake gaskets that will work with the injectors....or maybe they are not in the way.

Looking for experience here.

Thanks.

[madmaxx]

Have you tried tightening your intake manifold bolts. Did you find them loose?, tight? I have heard of issues with intake manifold gaskets allowing coolant to leak but how would one cause an increase in oil consumption?

[wrogers55]

I could really use some expert analysis here as I tackle my motor problem.

Quick Review: 418 SB, AFR 205, big lumpy cam, Mass-Flo injected, dyno 560ish on pump gas. Professionally built with all the right parts. Motor starts, runs and pulls perfectly. Runs cool and oil pressure is great all the way across. Oil consumption is excessive at a quart every 200-300 miles. No leaks. No start up smoke, no smoke at cruise, no smoke at closed throttle, wispy smoke from passenger side pipes only at shut down, smells "funny" like wax burning. Compression was a solid 200-205 all cylinders, dry cranked.

Key Point: Plugs look perfect, EXCEPT the two middle cylinders on the passenger side....they are fuzzy black after only a short run.

My plan was to replace the intake gasket first and I have a top of the line SCE to put in there. If that didn't solve it, then on to the valve stem seals. If that doesn't do it, then I would move to the rings.

NEW INFORMATION: I really hope someone can diagnose and either confirm or lead me in a new direction. The motor has a low speed ping or clatter on the passenger side, when you first come on the throttle, off of idle. I get a familiar clatter that sounds like it is only the two suspect middle cylinders and a LOT of blue smoke at that time. It clears up after a second or two and the exhaust runs clear after that, for the most part. On hard acceleration in second from 2,500 or so, no smoke at all and runs great. Turn it off and I get that wispy smoke that smells like wax burning out of the right side pipe (every time). It doesn't clatter every time.....clatter, lots of smoke, no clatter no smoke. I just running it enough to try to determine what to do next.

Can oil being sucked into the cylinder via an intake gasket leak cause the pre-ignition? Can that be the source of the smoke and not the rings? Maybe to much air as well causing the ping?

I know the rattling or pinging is rocking the piston or pistons skirts around on that side of the motor and I suppose that might make a broken ring or rings oil control situation worse. I just don't understand how rings would be considered the prime suspect with only two of the cylinders, next to each other on one side of the motor, look to be the first line problem (fouled black plugs there only).

I'm ready to start pulling things apart but if I really need to just go deep into the motor I had rather do it up front and not one step at a time, all of which will need a do over if I have to look at the rings. On the other hand if it's a simple leak at the intake sucking oil, that's certainly where I would like to start.

I guess my main question is can sucking oil through an intake gasket leak cause the pre-ignition. If so, I think the smoke at that time is coming from the intake leak. I just don't feel comfortable that I understand it well enough yet.

Man, any help here from some experience or expertise would be greatly appreciated.

[tcrist]

Wayne,

Contact Craig at Top of The Hill in Livermore. He might be able to help. At the least, he is fairly close to take it to and have him check it out.
http://www.topofthehillpc.com/

[Jac Mac]

Fairly sure you will find its the intake gasket thats causing this, but one other thing to check is that the inlet rocker studs have had sealant applied where they screw into the heads, IIRC the AFR heads are not blind in this area and can pull oil down around the threads if sealant is not applied. The point you make where the pinging only seems to occur after a period of high manifold vacuum tends to point in an oil leak around the intake port of these cyls.

[Rick Parker]

Yes oil can get by a compromised intake gasket and it will quickly create deposits, espaecially at the consumpsion rate you describe. The depisits will form on the back of the intake valve and in the combustion chamber bits of it will glow and cause preignition.
Attackt the intake gaskets, that where you'll find the problem. While you're at it look in the intake ports for signs of oil being pulled past the rocker stud threads, address as needed.

[DAVID GAGNARD]

You can also pull off the header on the passenger side and look at your exhaust ports, I'm betting the 2 middle ones will be oily/cruddy looking and the other two will look fine/dry.........

David

[Dwight]

if you pull the head check the cylinder for scratches. Lainhart had a smoking problem with his 427 s.o.
It would smoke when you accelerated from 50 mph. It would not smoke at idle or cruising at 50.
I pulled the intake thinking it would be the gasket. Could not find any sign of a problem. Pulled the head and found two small scratches in number 2 and 4 cylinders.

Lainhart took the motor to Keith Craft, who honed it .002 and replaced the pistons. He also installed a stroker kit. Now it's a 487 S.O.

Dwight

P.S. the only thing that smokes now, is the back tires.

[olddog]

The way you describe the two sooty black plugs, came across to me as if those cylinders were burning rich. Maybe oil? It's hard to say from a description.

Since it is EFI, if the outside cylinders were sucking air in at the intake ports, that air would not be measured by the MAF sensor, and the outside cylinders would burn lean. If in the close loop mode, the O2 sensors would see lean and it would richen up all four cylinders on that bank. This would cause the inside two cylinders to burn rich, if they were not leaking in extra air, as are the outside two in this scenario.

Is this a MassFlow as in it uses a single plain carb intake with injector ports welded in and a throttle body that looks like a carb, where there is a GM MAF meter inside the air cleaner? If so and the intake gaskets are leaking, it is a real possibility that the MAF meter is coated up with oil.

Dumping way too much fuel can wash all the oil of the cylinder walls and cause ring wear. The compression seems to be the same on these cylinders so that does not make sense.

[wrogers55]

Yes it is a Mass-Flow and the sensor wires were oil coated when I first looked. Called mass-flow and got some advice and a clean up process. Worked fine but no change at all to my problem. More like a symptom of my problem.

I think I have enough info to proceed pretty comfortably with the intake gasket.

Actually found a couple of service bulletins on Dodge V6s and one from Ford describing my problem exactly, oil consumption, smoke under high vacuum, and ping off idle under load...all related to an internal leak of the intake gasket at the valley.

I'm just going to get after the intske gasket and will post pictures of what I find for others with the same issues.

Very helpful board that is a blessing to all of us.

Thanks for all the posts!

[wrogers55]

Long thread but the problem has been found. Intake gasket slippage when installed it appears. Double gaskets, no sealer, except at water ports and the intake side slipped a bit as you can see. Kind of the sway back horse look of one gasket in the photo. It dropped down just enough not to seal up the intake side from the valley and started sucking oil and pinging/ratteling on the the two middle cylinders where the gasket failed. Or the builder failed. Something failed.

I'm putting a SCE premium gasket back in and really temped to seal it up with something......I still have two unopened tubes of Hylomar Blue and man it is tempting to coat that gasket, stick it to the head first and hope I never have to do this again.

Pictures for those interested or still suffering. The manifold was installed with a double gasket, black side to black side. It easy to see where one gasket slipped down and uncovered the intake port to the valley. Those are the middle two ports and the intake side looks droopy in the picture. Just enough to really create a problem. I don't know why the double gasket, or maybe that's the way the Corteco that failed is designed.

This is the first time I have been confident that I really understand and can see the problem. It all started with a one side ping, got worse, started using oil like crazy but little smoke and it comes down to a failed intake gasket. Actually, I'm pretty happy. Could have been much worse, assuming this fixes it.

Hope this helps someone (including me).

Thanks for all the posts. I'm on the way to recovery!

[zrayr]

what weight Mobil 1 are you using. If not using Mobil 1 15w-50 already, then switch to it. That weight oil has been very very good to me.


I'm a firm believer in Hylomar, It really works on gas, as well as oil.


Z.

[Jac Mac]

Just curious as to the original installation of two gaskets per side, was this done for port alignment or to gain enough room for the valley corks? There are /were two thickness valley corks available for 351w ( one about 0.100" thick & the other about 0.180" ), or you can cut your own if reqd to get a suitable setup.. along with some good sealant.

[wrogers55]

No idea on the two gaskets per side. Motor was professionally built and delivered. But there was no valley gasket front or back, just a bead of black silicon on both ends. Standard way of doing things as I understand on these small blocks.

[blykins]

That's what I use....gaskets on the side, silicione on the china walls.

If they used two gaskets, I would check intake fitment. If just one regular thickness gasket it used, the intake could sit way low on the heads.

[Snakebit]

That was my problem. My Weber intake manifold was sitting too low with a 1/16 gasket installed. SCE makes a 1/8 gasket which solved the problem. Use the Hylomar on both sides of the intake gasket and a bead of "The Right Stuff" in place of the cork end seals.