98 dodge 318 pickup consumption and oci

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Jun 28, 2014
In the field
Guy at work says it burns a quart per 2500 miles. Runs Dino. Says he overfilled it with 6 instead of 5 by mistake one time and thinks that's the reason. He does 2500 oci and only puts on 5000 per year. I recommended going to a hm oil like maxlife or pennzoil 5w30 and doing 4000 or 5000 oci. My only concern was the short tripping fuel dilution . He plows with it too. Adding oil would freshen it. Thoughts?
A quart in 2500 miles in not excessive, certainly not for a 318.

Why the HM oil? Are the seals leaking?

If he gets it hot enough the fuel will burn off and his oil level may drop, that's the concern. How about a UOA to see what he has in place now?
HM is good if the seals leak, it usually has additives that "swell" them to buy you time. For the most part think "marketing gimmick."

If he's been using a quality oil with regular changes just keep doing that.

All engines use some oil and he doesn't have a problem at that rate.
You'll be hard pressed to find a 318 or 360 that doesn't consume oil.

I personally consume about a quart every 5000, but some I've had consumed a quart every 3000.

I recommend a good conventional oil (PYB, MS5K, Chev Supreme, Havoline, Peak, Shell, Supertech, Quaker State, etc) and a good filter like a Fram ultra or Bosch D+ or MC FL-400S or WIX.

Change it once a year and keep it topped up.

I also recommend 10w40, unless in a sub-zero climate, because UOAs suggest chrysler LA engines prefer oil thicker than the 10w30 they are specced for. I think chrysler specced 10w30 for emissions reasons.
I had a 96 ram with a 318. Didn't consume any oil and it had 450k when I gor t-bones at a set of lights. The engine is very durable however I went thru 2 transmissions but I was towing a lot and overheated the tranny when it happened.
I used the cheapest oil I could buy,and changed it at 5000kms.
Great trucks. Changed the truck game.
Don't they usually drink it through the I/M valley gasket? A lot of these trucks ping too from the decreased octane of oil plus gas.
The plenum gasket, yes, it is a common problem.

But he'd be using a lot more oil than he is now. 2500/qt is not excessive.

The "old" rule of thumb used to be 1 quart per thousand.
Plenum gasket is usually the cause on these. I have a '99 with the same engine and it does the same thing. I replaced the plenum gasket a couple years ago with the Hughes Engines plenum kit and it's still burning some oil. They sent me a replacement gasket and new seals and bolts to redo it but I haven't had the chance to get around to doing it yet. Plan on at least a day of work to fix if you do it yourself.

Here's the kit: http://www.hughesengines.com/Index/products.php?partid=27091

Here are the instructions: http://www.dodgeownerforums.com/smf/index.php?topic=9504.0

Also, at 2500 miles per quart I wouldn't bother with doing anything yet. Once you start pinging and get down to 1000 miles per quart I'd start looking into fixing it.
My '98 360 is in better shape internally now after realizing there were some pretty nasty deposits of coking and sludge in the lifter valley which was apparent when I removed the intake to do the plenum gasket. Eventually I did an upgrade to a Hughes Air Gap manifold to avoid the weakness with the 2pc kegger. Over the past 11 years I have done several Kreen cleanings. My motor is much cleaner under the valve covers and uses almost no oil now between changes, the ring packs have got to be cleaner also allowing the oil control rings to work/seal better. 166k miles.
my buddies 1996 with same motor burns a quart about every 2000 miles....and he tops it off, before the next OCI.

He's got over 198k miles so far, and is the original owner. No issues with the motor otherwise.

as stated before, 1 qt every 2500 miles on that engine is not a concern. the 318 is very durable and known to last a very long time. yes, the intake belly pan gasket is a common failure - but easy to diagnose.
I had a 1979 and it burned a qt every 2000 miles
These were also very prone to rear main seal leaks like most Mopars but very reliable engines
My 93 half ton with a 318 magnum never consumed oil. I gave it regular 3K oil & filter changes mostly with Havoline conventional but some other brands of conventional when Havoline wasn't on sale / rebate. I gave it to my sister in 2002 with around 150K miles on it and no idea what she did with it after that.
My 360 magnum is carbureated,so I have never experienced the plenum issue, but I've heard of it. And I have been told the Hughes kit is the best solution for the plenum issue.
i have never seen my 360 magnum consume oil, I can go a year on the same oil and it's still full on the dipstick. I run synthetic oil though.
I would reccomend a synthetic, like valvoline synpower or mobil 1.
Overfilling a Mopar small block with 1-2 quarts of oil will not cause any crank foaming or PCV valve issues below 5k rpm, so I doubt thats his problem.

10w-30 in winter and sometimes 10w-40 summer for non Magnum motors is fine.

None of my small blocks burn oil, though I have a Hughes belly pan kit on the Magnum.

I suggest checking valve stem seals on any variant, and maybe a full OCI of Rislone concentrate (small bottle) to clean any carbon deposits in the top piston ring area, + change out the PCV valve with every air filter change.
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