I read over all the stripped oil plug posts because mine started
leaking a year ago (1990 Integra, 120K miles). I finally took it to a
shop that said they might be able to retap it. Turns out the oil change
shops I trusted to change my oil already had the largest self-tapping
plug in, an after-market plug labeled "M14-1.5". I found the same plug
at a local auto parts store for under $5.
The repair shop that initially said they might be able to retap it said
it would cost $550 to install a new pan. The Acura dealer quoted $450 &
another local trusted garage quoted $381. I decided to have AAA tow the
car to my driveway so I could check it out myself. The Internet said
all the parts to replace the oilpan myself were just $150. How hard
could it be?
I jacked the car up in my driveway, looked under & decided it was not
the job for me. I wasn't about to risk divorce or an HOA complaint by
first disassembling everything from underneath the car that was
blocking free access to the oil pan. I did pull the plug out and took
it over to show my 70-year old neighbor who has half a machine shop in
his garage to work on his own cars.
He looked at the half-chewed up plug and the metal plug gasket that
Acura sells to go with their stock oil plug and advised me to hold onto
my $381 and try a better gasket solution. He said that the threads on
the plug & the pan don't create the seal that keeps the oil off my
driveway so the plug threads were not creating an unfixable problem. He
said the critical seal was between the head of the plug, the washer &
the outside of the oil pan where the washer rested. He said since the
oil in the oil pan was not under any serious pressure when the car was
running that the problem might be fixable with a plastic oil plug
washer/gasket if the threads could still hold just past finger tight.
He advised that he could make a couple washers for me that might work
out of a flat sheet of nylon material he had in his garage.
An hour (and two beers) later I had two nylon washers that together
were about 1/4 inch thick. One might have worked but the threads
closest to the plug head were pretty chewed up. (I told my neighbor I'd
gladly buy another M14-1.5 plug at the auto parts store but he would
not hear of it - a different generation). The inside holes of the
homemade washers were about 9/16th of an inch & just cleared the
threads on the oil plug. The outer diameter of the nylon washers were
just larger than the oil plug head.
I dropped the washers on the oil plug, cleaned the outside of the oil
plug whole the best I could and finger tightened the plug with the new
homemade nylon washers on it. I then gently tightened it just a bit
more with the wrench until it was past finger tight. I pulled the jack,
put in 4 quarts of oil and ran the car for 5 minutes. When I looked
under the car at the oil plug it was dry & drip free. When I took over
a case of beer to my neighbor that may have saved me $381 (plus tax) he
said that since I installed the washers on a cold night they would
expand slightly when the car was hot to create an even better seal.
I'll log back in & report if it starts leaking again. (I can't imagine
it will leak worse than it was leaking with the metal Acura oil plug
washer). My neighbor said he'd have made the washers out of a
polypropylene material if he had had any.
In planning what I'll do if this fix doesn't hold, at the auto parts
store I learned that the M14-1.5 plug I have in the oil pan is the
largest self-tapping plug sold locally. They did have larger non-self
tapping plugs but the auto parts guy advised that the oil pan would
need to be dropped to tap a new hole to prevent any metal shavings from
getting into the oil pan. He advised a metal shaving in the oil might
seize up the car. I took it under advisement as I'm sure the oil change
shop guys that hid my problem from me by inserting the first self
tapping plug didn't pull my oil pan off before jamming the self tapping
plug in. I assume that the oil filter would filter out any metal
shavings floating around in the pan. I told the auto parts guy that I
was trying to avoid pulling the pan. If I was going to pull the pan I'd
pop for the $150 to replace it.
Needless to say I'll be changing my own oil from now on. Does anyone
know how easy or difficult it is to change the oil filter on a 1990
Integra? Do you need the special wrench?
Good luck with your Acura oil plug leaks!