I have an 89 IROC 350 tpi and know that the drivers side freeze plug above the oil filter is leaking. I assume that if one is bad the others are going or already gone. My question is which freeze plugs can be changed with the motor in the car. I know there are 2 on the back of the motor that you have to pull the tranny for but there is no leaking from them yet.

 

I also saw that they make rubber plugs with a bolt in the middle to expand the rubber to form a seal. Anyone have any idea if these would work just as good as new brass plugs. Any help would be great.

 

No help? Anybody?

 

The rubber plugs are fine for a replacement. The plugs in my 89 were brass from the factory. I took one out to replace them all and left the rest of them alone when I saw the brass. Kind of surprised that you have one leaking. Are you sure it's a freeze plug and not a head gasket?

 

I was able to get a mirror down there and could see it leaking from the plug just above the oil filter. If they are all brass i might just change that one. I just needed to know which ones i could change with the motor still in the car.

 

it's a pain to install a freez plug with the eng in the car..it can be done..
use brass to replace it..they go in a bit more easy..

for a short time fix..2 to 3 years you can use the rubber plugs.

 

I was able to get it in the shop thanks to a good friend and replaced 4 plugs. Not all were leaking but i had it on a lift and all the tools so i replaced them. 2 behind the motor mounts, and the mounts had to come out but they needed replaced anyway. one above the oil filter was easy and then one behind the starter. I did use brass, about $2 each from autozone, i just hope the ones on the front and back of the block hang in there for a while.

 

i know its kind of an old post but im about to do this. lost one at the track and now im just going to replace them all. any idea if after market headers instead of exhaust manifolds will make this more challenging. id really like to do it without pulling the motor.

 

with so many makes it hard to tell, just take a look.

side note: always use sealent on them,

 

yea i will just not silicone this time around like my machinest did

 

you can use it.. but its got to be ultra blue or ultra black. it's O2 safe

 

O2 wats an O2 haha.

no silicone tends to get greesey and slick when it gets hot. my old man uses sumthin that works pretty good. cures hard so thats wat im goin to use this time around

 

we use ultra black, in place of the intake front/back seals.
and on all freez plugs. works Fantastic. never leaks.

 

a little off topic . does anyone know when G.M. started the use of brass freeze plugs ? a while back i pulled my tranny for new clutch etc. . being the type that only wants to do things once . i had new rear main seal & freeze plugs ready . did not need them , got me wondering about the brass plugs . anyone know ? thanks .

 

Core plugs aka Welch plugs have been around a long time and were used in the US as far back as the model T! The company that made/invented? them was bought by GM!
Heres some history on the Welch plug:
http://www.britishcarweek.org/welch_plug.html