Oil plug size

[mitchell2345]

Hi,

I ordered a oil drin kit so next year oil chaning is much easier...I ordered a 1/2 - 20 thread size and its just barely to small. This is a 95 Chevy 5.0 305. I am guessing i need 12mm x 1.75. Can anyone confirm?

Thanks,
Mitchell

 

[Don S]

Re: Oil plug size

You may not have a drain plug, have you checked? You should have your dipstick tube fitting on the bottom of the pan instead of the plug.

 

[mitchell2345]

Re: Oil plug size

oh its there...i just drained the oil out of it!

 

[mitchell2345]

Re: Oil plug size

Engine serial 0F274600

 

[Don S]

Re: Oil plug size

Should be 1/2-20 according to this chart.

 

[mitchell2345]

Re: Oil plug size

def not...it went right in the hole. I Had to take it off with a 12mm socket. which I though was really weird. Looks like its the one below that.

 

[NHGuy]

Re: Oil plug size

Take the plug you removed and check it with a thread checker. BTW if an inch is 25.4m then a 12 is even smaller than the 1/2 20. Do they list a 14 mm or a 9/16 or a 17/32d's?

 

[Fishermark]

Re: Oil plug size

It's also possible someone installed an oversized plug due to stripped threads.

 

[mitchell2345]

Re: Oil plug size

well this project will just have to wait for next year...i just gave up and put the org plug in and and filled the oil back up. 5.0 should take about 5 1/2 qt's right? Dip stick is tough to tell....

 

[ktbarrentine]

Re: Oil plug size

My 1990 5.0L has the 1/2-20. +1 to the possibility of an oversize plug installed. Do you have the maintenance history on the engine?

 

[ktbarrentine]

Re: Oil plug size

well this project will just have to wait for next year...i just gave up and put the org plug in and and filled the oil back up. 5.0 should take about 5 1/2 qt's right? Dip stick is tough to tell....

Your service manual gives the capacity, but also advises to use the dipstick as the primary means of determining if you have the "right" amount.

http://boatinfo.no/lib/mercruiser/manuals/mercruiser17.html#/28

 

[mitchell2345]

Re: Oil plug size

My 1990 5.0L has the 1/2-20. +1 to the possibility of an oversize plug installed. Do you have the maintenance history on the engine?

haha...i only wish i had any docs. def dont have that luxury.

 

[Don S]

Re: Oil plug size

haha...i only wish i had any docs. def dont have that luxury.

Where did the serial number you posted come from? Decal on the plastic flame arrestor cover?
Is there a serial number tag on the back of the block just above the starter and next the the flywheel cover?
If there isn't a tag there, you may not have the original engine. Happens a lot in boats. Usually from cold weather freeze damage from improper winterizing.
Don't forget, the information we give is based on the information you give. If you have a newer engine or a newer oil pan due to rust, we have no way of knowing.

 

[mitchell2345]

Re: Oil plug size

Where did the serial number you posted come from? Decal on the plastic flame arrestor cover?
Is there a serial number tag on the back of the block just above the starter and next the the flywheel cover?
If there isn't a tag there, you may not have the original engine. Happens a lot in boats. Usually from cold weather freeze damage from improper winterizing.
Don't forget, the information we give is based on the information you give. If you have a newer engine or a newer oil pan due to rust, we have no way of knowing.

ill take a look in the morning. that would be good knews for me if its a newer engine!
thx.