New 318 used 1 quart of oil on long trip.

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my5thmopar

my5thmopar

Life Long MOPAR Owner
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I had a great vacation trip in the Dart. It ran flawlessly and I'm pleased but...after 450 mile trip engine used 1 quart of oil. This isn't the first time I've noticed oil usage. I used cast rings, I think they are sealed power. The engine has 2800 miles on it now. Block was bored 30 over. I don't know what type of boring machinery was used. I don't think engine is leaking since I don't see any oil on floor or underside of the body. I'm wondering if a bad head gasket or intake gasket is the culprit. I don't have any visible smoke, that's the confusing part. I can borrow a leak down tester, but I've never used one. Is this best approach?

Thanks Craig
 
Mine uses a quart to every 200 mile doesnt smoke either and runs like hell, I just keep it full.
 
Check the plugs .Maybe ones a little blacker than the others. Could be as small as a valve guide seal.Could be sucking some thru the pcv if the valve cover isnt baffled also.
 
Have the heads been milled any? Bottom of intakes can have sealing problems with ports using stock steel gaskets especially if you use the end seals on the block for the intake sometimes they just wont seat tight enough at the bottom.
 
My 318 uses about the same,1 quart in about 500 miles. Also with less than 3,000 miles since freshing. Stock iron rings too.(No smoke)I'm running 4.10 gears and it buzzes up there at highway speeds.Maybe like mine it wasn't built too tight,not like today's engines that run super lightweight oil for the tight clearances. Back in the 60's and 70's 500 miles was pretty much normal. It is getting better the more I drive it.
 
I find that kinda strange, I've put over 5000 miles on the motor in my dart, and I have a rather significant Rear intake gasket leak, and it's only used a quart since I changed the oil 1500 miles ago. Maybe it's a break-in thing, I dunno. I did have to top mine up before I short-changed the oil after the first 500.
 
I'll have to say that 500 miles per quart indicates that something is definitely wrong. Are you sure it isn't smoking a little? Any oily film developing on the back bumper?

Is your PCV system stock, or close to it? If so, plug the breather inlet with your thumb with the engine at idle. You should feel vacuum build up in 2-3 seconds. If the idle speed changes, you have an internal vacuum leak (intake ports or valve guides). If vacuum does not build, your PCV valve may not be working properly. If pressure develops, you are losing compression into the crankcase, meaning your rings aren't sealing.
 
:banghead: Here are the issues I found during testing tonight. I definitely have oil in the cylinders. Right bank 2 slightly wet, 4 wet, 6 and 8 dry. Left bank 1 slightly wet, 3 and 5 dry, 7 very wet. Compression 155 on 2,6,8,1,3,5. Compression 160 on 4 and 7. The engine boiled over during break in because I didn't burp the radiator. Maybe the head gaskets were damaged from the beginning. I’m not loosing any antifreeze and there isn't any oil in the water or vice versa. So, I'm back to square one. Is it more likely head gaskets or intake gaskets. How can I test this?

I’ll address some questions asked earlier. Noticed some light smoke acceleration tonight.
ProComp Valve guide seals were replaced with stock Victor.
The PVC system is stock. PVC valve is new stock covers with baffles both sides. PVC in on driver side and breather on other.
I recently changed the manifold gasket because I used the metal intake gasket. I used the Felpro 1213 and RTV on ends. Intake is Edelbrock 2176 to iron heads. The heads were cleaned on machine but not milled.

PVC Test: No measurable suction on the right cover. PVC is connected to the Edelbrock 1406 front port. It is pulling pretty hard. Vacuum is at 20 at full right port. I don’t seem to be getting any pressure from crankcase.

Plugs look almost text book. Nice brown/tan. Heat range pretty good close to half way.
 

Head gasket failures on Mopars generally don't result in oil leaks, and wouldn't affect outer cylinders.
 
my5thmopar said:
:banghead:Plugs look almost text book. Nice brown/tan. Heat range pretty good close to half way.
Click to expand...

Is it too late to post pictures of the plugs?

I had a bad ring on one cylinder and the plug deposits were brown while the other plug deposits were lightly gray.
 
make sure your valve seals are still good.I like useing the stock type intake,flatter,wider ones on all the valves gives more of a umbrella shield.A wet plug doesn't mean its oily as if the motor was shut down some cylinders still have fuel in them as its winding down and not firing.That much oil missing in 500 miles if it was getting in one or two cylinders the plug should be very dark to black.
 
Also what oil do you run?5w20 has a may of disappearing after a few miles on it.
 
Thanks for all the help. I'm not quite sure how to address the issue. There is a problem. There is an oily mess on the top of some the pistons. I looked at the plugs again. The #7 plug has some oil on it and the piston is wet with oil. The rest have are somewhat black on the electrode ring. I really don't think it is a ring issue. The ring gaps were all checked/ and rotated per the ring manufacture's suggestion. I guess my only option is to pull the heads. I was hoping for a way to determine what is wrong before tearing into it. But anyway that should at least eliminate the top half.
 
Before I tore anything apart, I would do a leak down check.
Testers are fairly cheap.
This will tell you what is going on with the engine.
My buddy gave me a dakota that had a miss in it.
One cylinder dead after compression test, leak down showed leaking exhasut valve.
It is alot easier to fix something if you know what the problem is.
The truck was free so my daughter ended up with a nice daily driver truck, all I had in it was a valve job on one head.
 
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