How much oil should my Six be leaking?

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Mr. Mopar

Mr. Mopar

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Hello,

Hate to start a new thread since there're already several others on the topic of leaking Slants, but I figure, eh, whatever.

I've just bought a '71 Plymouth Scamp, not only my first classic but my first car generally. It's got a 225 Slant Six that's largely original, from what I understand, but runs well.

I know a little about cars, but not how much oil a Six like this should be leaking. I've heard that it's normal for these things to leak some oil, but how big of a stain should they be leaving behind?

I took two readings off the dipstick, engine cold, and it'd gone from the "Add" line the day after I bought it to below the "dd"s in "Add" the next day.

If I brought it into a garage like Mr. Lube or Canadian Tire, would they be able to discern much about what's leaking without removing the K-member?

Also, judging by the location of the stains under the car, it may be leaking a bit of tranny fluid, I think. Is that also normal?

Sorry if these are stupid questions, but like I said, I'm sort of a :newb:.

Thanks for any help.
 
Where is it leaking from.

some big culprits for leaks are: (from the top of the motor down)
valve cover
timing cover
rear main seal
oil pan

I would start by taking the new whip to a local spray wash and really cleaning the motor with a power washer. I would SOAK it in simple green or something like that first to help clean up the mess from any and all leaks/oil grime.

Then keep a close eye on all these parts/areas for where your oil is leaking from. look all around the parts for new oil drops or seepage and then work to replace the necessary gaskets until the leaks are gone. Like said before, it shouldn't leak at all really... But, some of the gaskets that are really difficult to swap sometimes get left for awhile based on oil consumption and vehicle use.


A valve cover gasket replacement is a simple task and perfect for a new member. The timing cover isn't so easy, because of the waterpump, but is doable. The oil pan is also a easy gasket, but a pain because you have to lift the motor a bit... The rear main seal is usually a "motor out" event. So these two are common ones that people usually " live with" for a while.

search for threads about the exact gasket replacement/location if your not up to speed with what is what...

You may also have luck starting a thread asking for a local member to help you figure out what is what. (be ready to supply some beer, and get dirty)

Goodluck, welcome to the site, my first car was a dart... still have it...


JOE
 
Don't forget to check for leaks at/around the oil sending (gauge or light) unit. Dripping oil from unsealed threads on fittings can dump a surprising amount of oil on the ground in a short amount of time, especially if the drip is a steady one.
 
one of my XJ cherokees had a leak out the front seal and every time i came to stop it tossed a little out the front. i used a quart every week. i looked at it as a continual oil change in slow motion. it had over 300,000 miles on it and every single day the oil looked as fresh as day one. LOL
 
No such thing as a stupid question around here,We all had questions about our first cars and this is just the place to get them answered so ask away


Bob
 
It shouldn't leak any oil or trannie fluid at all. BUT I can tell you my dart leaked tranny fluid like crazy untill the transmission service was done. The transmission fluid pan was leaking at the gasket. Check the gasket.

If you do your own work, jack up the car and look for the fluid smeared down the bottom of the car. Of course, this only works if the car has been driven a decent bit with the leak. Look around the pans and see if the fluid is originating there. Look at the rear of the tranny, near the driveshaft. If its wet there then the rear seal is bad and it can be replaced by dropping the driveshaft. Look at the front of the tranny where the bellhousing mates to the block. Red fluid means the front transmission seal is bad and the transmission will have to be dropped. Black/ brown means the engine rear seal is bad and that might require pulling the engine or just dropping the transmission to repair. Look at the bottom pulley on the front of the engine. If its wet there then the front engine seal is bad and that might be replaceable with the motor in the car, I don't know.

Also, pop the hood and look at the top of the engine around the rockerarm cover gasket and see if it's wet there, the rocker arm cover is to the left of the intake manifold and is on top of the cylinder head, it has the cap on it where you add the oil. If it is leaking, go get a gasket (felpro is good, don't use form-a-gasket unless you're really good with it) and replace the gasket here. MAKE SURE THE MATING SURFACES FOR THE GASKET IS CLEAN ON BOTH THE HEAD AND THE COVER. Use a putty knife to scrape any old gasket off. While you have the rocker arm cover off, go ahead and adjust the rocker arms cause you have to do that periodically anyways and theres no telling when it was last done. Get a set of feeler gauges and with the motor HOT AND RUNNING, slide the .010" gauge between each rocker arm and the valve. The valves are the little stems you see under the driver's side of the rocker arm protruding from the head. Use the bolt in the middle of the rocker arm to adjust the lash. Small adjustments here, and your shooting to have the feeler gauge slide in and out snuggly. While you're in there, make sure the pushrods, that protrude from the passenger side of the block and make contact with the rockerarms, are covered in oil and rotating. One last thing, since you're running the motor with the rocker arm cover off, you might have oil spraying everywhere if you have high oil pressure.
 
/6 Matt said:
Get a set of feeler gauges and with the motor HOT AND RUNNING, slide the .010" gauge between each rocker arm and the valve.
Click to expand...
Whoops, I told you wrong. Use the .010" gauge for the intake valves and the .020" gauge for the exhaust.

This is the order of the valves.

Exhaust
Intake

Exhaust
Intake

Exhaust
Intake

Intake
Exhaust

Intake
Exhaust

Intake
Exhaust

This list is viewed as you would view it if you were standing in front of the car. The bottom of the list is the front of the engine and the top is the back of the engine. If you're ever in doubt about the orrientation of the valves, just look at the intake and exhaust manifold. The manifold runners will correspond with the valve. IE, the intake runner will line up with the intake valve and the exhaust runner will line up with the exhaust valve.

Please anybody, do correct me if I've told him wrong. It's been awhile since I adjusted valve lash.
 
its normal for an old engine to use a quart of oil every 5000 miles. if your leaking it check where its coming from, could be serious or it could be something you just need to keep and eye on
 
Get you a engine lower shield like on a 06 charger and others,install a belge pump so it recycles itself.Call it an air cooled oiling mod.:toothy8::toothy8:
 
You need to determine how much of the daily loss is from leaks and how much is burning. Put a newspaper under it to monitor the leaks. I have several cars that are usually wet underneath, but they leave few spots and use negligible oil. A little oil can hang around a long time. I just keep a metal pan under to protect the driveway. My Mercedes are always wet and diesels have the blackest oil. Indeed, I can't recall owning a car that didn't leak oil within 3 years of being new. Worst was my 2.4L Plymouth. It leaked oil from the head gasket to outside, which was a design problem I fixed only by installing an MLS head gasket.

Trannys usually leak from the bottom pan. No big deal since it needs to be removed every ~100,000 miles for a filter, fluid change, and band adjustment anyway. They can theoretically leak from the front shaft, but I haven't seen that. Good since fixing that requires removal. If you over-fill them, they will burp oil out.

Good you don't have a bottom engine shield. My son's Chevy Cruze has one, with a current recall. Seems quick lube monkeys spill oil, which has caught fire sitting on the shield.
 
Thanks for the tips and advice, everyone. If a quart every 5,000 miles could be considered normal, then, yeah, I'd figure it's losing a much higher than normal amount of oil.

After crawling under the car with a torch, I can pretty certainly say it's coming from the head gasket, since there's oil coming all the way down the side of the block starting at the head.

The tranny's leaking quite a bit, too, but it's all over the underside, so I'm not sure where the source is. It's mostly around the pan, though.

Will hunt down the other FABO threads on these sorts of fixes, now. But thanks again for the help!
 
Oil leaking from head gasket to outside is very unusual, though that was the problem with the early 2.4L engines. Most likely source of your oil leak is the valve cover and/or the spark plug tube seals. The later were on earlier slants, I know in 1969 (had one) and I think your 1971 too. Leaks are so common that wags here call those "drool tube heads". You can still buy replacement rubber seals cheap, ~$1 ea I recall at rockauto.com. If those ever disappear, I once used O-rings on mine. Be sure to take the metal gasket off the spark plugs (many posts).
 
BillGrissom said:
Most likely source of your oil leak is the valve cover and/or the spark plug tube seals. The later were on earlier slants, I know in 1969 (had one) and I think your 1971 too. Leaks are so common that wags here call those "drool tube heads". You can still buy replacement rubber seals cheap, ~$1 ea I recall at rockauto.com. If those ever disappear, I once used O-rings on mine. Be sure to take the metal gasket off the spark plugs (many posts).
Click to expand...

Now that you mention it, it does look like the leak is more specifically coming from the #1 and #2 (and maybe #6) spark plug tube boots.

Hopefully I'll have her sorted out this week. Well, the oil leak. Not sure about the tranny.
 
I have never owned a Mopar that didn't leak except for about a week. Get used to it otherwise you'll drive yourself crazy. I say just fix the big leaks and don't worry about the rest.
 
good tip on cleaning the motor at the local car wash,, but be careful the slant six exhaust manifolds are really prone to cracking,, if hit with water when they are hot,,,
so,, no problem,, just get there early, let the car sit for an hour or so till the manifold is good and cool,, put some foil over the distributor and go at it..
 
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