Oil drain plug leak....?
#1
Le Mans Master
Thread Starter
Oil drain plug leak....?
Been trying to figure this ever-so-slow oil leak. Tiny drops surround the drain plug and spots the floor. Takes a few days to show up on the plug and floor after wiping clean. Changed the drain plug to a new one last fall, but same results.
Since this car is so low to start with, I wonder if previous owner may have slightly hit the front of the pan or plug just enough to mushroom the pan around the plug, and maybe the plug doesn't tighten up flush?
Anyone had this issue? Leak is definitely from plug area.
Since this car is so low to start with, I wonder if previous owner may have slightly hit the front of the pan or plug just enough to mushroom the pan around the plug, and maybe the plug doesn't tighten up flush?
Anyone had this issue? Leak is definitely from plug area.
#6
Tech Contributor
It sounds like the sealing surface, on the pan drain tapping itself, is not smooth and flat.
Try a soft copper sealing washer on the drain plug in place of the rubber seal.
Try a soft copper sealing washer on the drain plug in place of the rubber seal.
#7
Le Mans Master
When you had the plug out, did you inspect the oil pan surface to see if it looked smooth?
If the rubber gasket will not seal, I doubt that a metal gasket will seal.
If the rubber gasket will not seal, I doubt that a metal gasket will seal.
#8
Le Mans Master
Thread Starter
Last fall during the oil change and plug change I believe I only concentrated on the plug, as I dont recall seeing anything unusual with the pan. Will be changing oil soon, so inspection of the pan will be next. I'm thinking its "sort of mushroomed or slightly crunched" just enough to not seal correctly, otherwise I have no clue what it could be.
#9
Burning Brakes
Last fall during the oil change and plug change I believe I only concentrated on the plug, as I dont recall seeing anything unusual with the pan. Will be changing oil soon, so inspection of the pan will be next. I'm thinking its "sort of mushroomed or slightly crunched" just enough to not seal correctly, otherwise I have no clue what it could be.
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tabbruzz (09-05-2016)
#10
Le Mans Master
Thread Starter
yup...I actually included teflon tape on the threads when new plug was installed....drip...drip...drip
#11
Tech Contributor
The plug has straight threads, not tapered threads like pipe fittings have. Teflon tape works best on tapered threads.
A thin coating of black silicone RTV over the rubber seal, before you install the plug each time, should stop the drip too.
A thin coating of black silicone RTV over the rubber seal, before you install the plug each time, should stop the drip too.
#12
Le Mans Master
Thread Starter
but there must be something wrong if that is necessary?
#13
Tech Contributor
There has to be a casting flaw or an irregular surface in the lower oil pan section, at the drain plug hole tapping. You'll have to drain your oil to do a close inspection of the area.
Look for any nicks or burrs in that area, and remove them with a Dremel tool.
Look for any nicks or burrs in that area, and remove them with a Dremel tool.
#14
Le Mans Master
Thread Starter
Well...the leak is back.......after draining oil, and inspecting pan a few months ago, I delicately filed the surface around the hole to ensure the surface was flat...installed new drain plug with seal. About a week ago started smelling the oil again ever so lightly sprayed over the bottom of the oil pan. Yet this time, no drops on floor. Smell is worse the more I drive especially at highway speeds.....is it time to change oil pan????
#15
Burning Brakes
Well...the leak is back.......after draining oil, and inspecting pan a few months ago, I delicately filed the surface around the hole to ensure the surface was flat...installed new drain plug with seal. About a week ago started smelling the oil again ever so lightly sprayed over the bottom of the oil pan. Yet this time, no drops on floor. Smell is worse the more I drive especially at highway speeds.....is it time to change oil pan????
#16
Le Mans Master
Thread Starter
When I changed my oil I cleaned off the teflon tape and put on a thicker O ring. That solved it for me. You could also try "Gasket Eliminator" on the threads or maybe the oil is coming from somewhere else and running down to the plug? You probably already checked that tho.
#18
Race Director
An idea...........Use a tap to restore thread or create new thread or buy a specially made oversize drain plug from an auto parts dealer. The one you want is designed to rethread damaged threads in the oil pan, allowing the new plug to seat properly and seal the leak. Start the plug into the drain hole by hand, and then use a wrench to seat the plug. Stop turning as soon as the plug is secure.
Different seals/washers require different torque requirements, depending on the material they are made of; do not overtighten...do not undertighten.
I have heard chrome plugs work best.
777
777
Different seals/washers require different torque requirements, depending on the material they are made of; do not overtighten...do not undertighten.
I have heard chrome plugs work best.
777
777
#19
Le Mans Master
Thread Starter
All these ideas are good ones, but have been tried.....I am almost certain oil pan must have been "mushed" at one time by previous owner thereby causing the drain hole not to be round (cannot see this by eye, BUT- there is a "flat spot" at the very bottom of the hole in the pan..)not sure if this was cast this way or been hit......
the drip is so slow it takes weeks to appear...maybe trade this in for a C6....
the drip is so slow it takes weeks to appear...maybe trade this in for a C6....
#20
Le Mans Master
Member Since: May 2007
Location: Belleville Mich.
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All these ideas are good ones, but have been tried.....I am almost certain oil pan must have been "mushed" at one time by previous owner thereby causing the drain hole not to be round (cannot see this by eye, BUT- there is a "flat spot" at the very bottom of the hole in the pan..)not sure if this was cast this way or been hit......
the drip is so slow it takes weeks to appear...maybe trade this in for a C6....
the drip is so slow it takes weeks to appear...maybe trade this in for a C6....
There you go. Problem fixed!!