slow oil leak

cmm24601

Well-known member
I hope i didn't blow a gasket...

I've got oil dripping a few drops a day off the front of the transmission. It seems to be coming off the back of the oil pan. No apparent oil leak on either side of the engine or around the head gasket, but I can't really see behind the engine.

This started after a 150 mile drive through the Smokey mountains. I got stuck in traffic on I40 and noticed some bluish exhaust. Engine temp got as high as 215. Engine performed great the entire trip.

Before I go tearing the entire engine apart... can you guys point me towards some likely culprits?
 
There's a special detail for the pan and rear main gaskets members on here follow for that area.
Not sure but it looks like U just installed your engine?
 
wonder if it's been leaking all this time?
Try the best to diagnose the exact leak location…
lotta times traveling down the rd, or even running the engine can "move the oil drip"
to displace what gravity does. Roof leaks in buildings can fool us on location (run down rafters, etc)
but this is even harder.
 
:unsure: Have you determined if it is motor oil or transmission fluid?Should be able to figure it out by smell.
Good luck.Have fun.Be safe.
Leo
 
Hi, If you determine the leak is engine oil I would GENTLY snug up the oil pan and valve cover bolts.I have stopped or slowed many leaks that way. Do not over tighten them or you can cause more problems. That should cure a gasket leak. A rear main seal or front tranny seal is a lot more work, so try the easy stuff first. Good luck
 
I've been tracking it down by wiping it off and waiting for it to drip again.

After about 24 hours... no more drips. Any thoughts? I'm going to fill it back with oil and see how it does.
 
how often do U put in how much oil?
more when driving vs just sitting?
do U see any of it burning (ie smoke out tail pipe)?
 
I just replaced the oil a few weeks and a 1000 miles ago. Something clearly went wrong on this trip to cause the leak and burn off. Hottest temps the oil pressure gauge fluctuated, which it never does.

I added a quart or two in the 6000 miles since the last oil change. I use full synthetic.
 
cmm24601":18cwujnx said:
I just replaced the oil a few weeks and a 1000 miles ago. Something clearly went wrong on this trip to cause the leak and burn off. Hottest temps the oil pressure gauge fluctuated, which it never does.
I added a quart or two in the 6000 miles since the last oil change. I use full synthetic.
Looks like you did an oil change (which includes filter) 1,000 mi ago. Not sure how much time ("...a few wks...").
Not sure if it's burning as well as leaking ("...the leak and burn...").
A Qt in 6,000 mi, not bad - 2 in same would be.

If ur concern developed after the oil change due to drips under the car & there were none B4 - look to changes created at that time.
Do U see smoke emitting from the tail pipe when running/warmed up (ie more than ~7 to 10 min when auto chokes flip for the i6)?
What color? White billow? grey soot? black cloud? 'nothing' to 'not much'…

What does the oil temp read or how high did it go for how long B4 it came to where it is now, normal?
 
I tightened down the oil pan (gently). It leaks again after idling for a few minutes. There's one bolt I can't reach due to a cylinder near the transmission. Pardon my ignorance, not sure what that is.

I'm pretty confident the leak is around the oil pan. Is it possible to replace the the oil pan gasket with the engine in the car? Basically, drain the oil, remove the pan, replace the gasket, reinstall the pan?
 
Yes you can replace the oil pan gaskets with the engine in the car it's not so hard. Good luck :nod:
 
If you have tried tightening the bolts on the pan in an effort to stop the leak, you probably have crushed the cork gasket and deformed the lip of the pan. If you do drop it, straighten it out with a straight edge and some pressure. Like squeezing it between two pieces of wood with a C-clamp. Also use a good gasket sealer and use a liberal amount of sealer.
 
leaks just while running - I'm leaning toward valve cover & its dripping down (as gravety will do).

"...the leak and burn…"
still uncertain if there's 'oil burning'.

"...possible to replace the the oil pan gasket with the engine in the car."
Oh, yes! but some R more difficult (steering linkage to move, etc).

What model do U have?
What components do U C under there? any in the way?
 
Hey Chad I have the 1969 250 "M" head.

I will check the valve cover again.

The problem seems to be getting more intermittent. I drove it to work. No leaks...

I did not see any smoke or evidence of burning this morning either
 
You know, Chad only posts all this practical stuff that actually works because he wants to keep his numbers up. That or maybe he has some valuable information to share. Something. I guess. ;)
 
ludwig":w6mtwq5t said:
You know, Chad only posts all this practical stuff that actually works because he wants to keep his numbers up. That or maybe he has some valuable information to share. Something. I guess. ;)

Yeah, like that gosh darned M head.

Not sure ur ultimate plans, cmm
( I've seen U here awhile so U probably know)
the head is an exellent candidate for the 2v direct mount carbs…

Ludwig - think U were da fourist 2 post 2 me as a "new guy" here. I remember it fondly'n have gotten some real kicks from ur sense of humor. Another dad-of-a-daughter makes a connection 4 me too (2 kids only, both, of the female persuasion).
(y)
 
You get your daughters into an activity and they won't quit. That's the truth. The Navy offered my daughter a slot at engineer school but she wanted EOD. Ended up in SAR. Now she's a CrossFit coach.

She and I rebuilt the whole suspension on the 66, front and rear. I did one side, she helped. Then she did the other side and I handed tools to her. We both dropped in the rebuilt engine. And it fired right up.

Better than sports, for a fact. Life skills.
 
'N a dad who knows how to guide (show; den step outtada way!).
God's Planned Obsolescence
we gotta get outta da way... all da way (@ some point.)
.
My Pops is 92. Better health than me. I still go 2 him for 'stuff'.
But not that way w/21 & 31 y/o daughters. Wouldn't B right, wait'n C
Wait'n C... just amazing what's happening. Simple reasons 4 joy.
:wow:
 
True dat. You never know just what you set in motion when they are small.

Don't worry. Your two will be asking dad all kinds of stuff, just not what you expect.
 
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