AF leak?

optionizerSS

Active Member
Joined
Apr 25, 2023
Messages
598
Reaction score
497
Location
Pittsburgh, PA
Just bought a 1995 GT 5.0 automatic. Brought it home a few weeks ago and it rained the whole week so it sat in the garage not started or moved. When I pulled it out there was a small puddle of anti freeze with 3 distinct drops about 6" wide. Looked like maybe a tablespoon full total. Monitored it for awhile but saw nothing for awhile. Parked the car this past Saturday and it sat unstarted until last night. This morning pulled the car out and again 3 drops. Measured from where the front wheels were and the drops are about 12" behind the front tires so back of block area. Measured left to right and its a little closer to the drivers side so next the drivers side of the engine.

Thoughts?

Hoping its something simple like coolant temp sensor but praying it isn't head gasket or freeze plug. I know next to nothing about the 5.0 engines as I was always a GM guy. We also drove the car about 200 miles last weekend with no issues, gauges were fine, etc. so doubt it would be a head gasket

Thanks!
 

maillemaker

Active Member
Joined
Mar 5, 2023
Messages
419
Reaction score
216
Not much coolant related plumbing on the back side of the engine, as I recall. I think the temp sensors are up near the front of the intake manifold. You sure it's not water from the air conditioning condenser?
 
OP
OP
O

optionizerSS

Active Member
Joined
Apr 25, 2023
Messages
598
Reaction score
497
Location
Pittsburgh, PA
definitely green AF and based on the tire marks in the garage and where the drips are i'd say near the back of the drivers side of the engine. i measured 37" from where the right front tire was and 27" from where the left front tire was...lol. Add the 6" or so width of the wet spot and that gives about 70" from one side to the other. Roughly 6" left of the center of the car. Wife has it at work now so I can't look at it till later but trying to gather info now.
 

ttocs

Post Whore
Joined
Oct 9, 2009
Messages
32,383
Reaction score
5,557
Location
Evansville Indiana
The only thing I can think of is maybe the back of the head gasket? I would have thought that would have happened when it was hot and there would be other signs though.
 
OP
OP
O

optionizerSS

Active Member
Joined
Apr 25, 2023
Messages
598
Reaction score
497
Location
Pittsburgh, PA
It seems to only leak after sitting awhile. We drove it 200 miles last Saturday and I kept checking every stop we made and nothing. Bring it home and pull it in the garage and nothing. 5 days later there are drops on the floor. Odd
 

RAU03MACH

Legend
Joined
Apr 23, 2019
Messages
6,716
Reaction score
6,508
Location
NEW MEXICO
tighten up all clamps on heater hoses.
sometimes after the engine cools off and the fluid cools the hosed will expand and retract along with the clamps.
thats normal
 
OP
OP
O

optionizerSS

Active Member
Joined
Apr 25, 2023
Messages
598
Reaction score
497
Location
Pittsburgh, PA
Just went out to look but it's too hot to stick my hand back there. I have one of those 'borescopes' that attach to your phone so will try using that to get good video of the back of the engine. Should be able to find it but being 'random' will make it harder to track down.
 

Pallgor

Member
Joined
Jan 16, 2022
Messages
125
Reaction score
78
Good luck. I’m still trying to find out why I smell coolant yet no puddles and held pressure when I tested it 3 times
 

ttocs

Post Whore
Joined
Oct 9, 2009
Messages
32,383
Reaction score
5,557
Location
Evansville Indiana
Good luck. I’m still trying to find out why I smell coolant yet no puddles and held pressure when I tested it 3 times
smelling it inside or out of the car? The heater core is known to leak inside the car and leave the pass floor wet with coolant. Sucks to change as you have to take the dash out to do it.
 
OP
OP
O

optionizerSS

Active Member
Joined
Apr 25, 2023
Messages
598
Reaction score
497
Location
Pittsburgh, PA
for mine i stuck an endoscope down behind the engine the other day and didn't see anything. Car sat from friday night until monday afternoon and had a few drops on the garage floor. gonna have to get it up on jackstands and crawl under it to get a better look
 
OP
OP
O

optionizerSS

Active Member
Joined
Apr 25, 2023
Messages
598
Reaction score
497
Location
Pittsburgh, PA
The leak appears to be very slow as my overflow tank has only dropped about 2" in a month. The drops were under the back of the engine but today I crawled under and looked closer. It is dripping from the rear of the oil pan, off the bottom of the rear main seal flange and off the rear oil pan bolts. Can't see any other oil at the back of the engine. So started looking at the front of the engine and there is AF slowly dripping from the front of the oil pan seal...but... up on top of the engine just under the t-stat housing on each side are little 'pockets' from the water pump and those are both full of AF so I'm thinking and hoping its the t-stat housing and its running down and back the oil pan rails. I think I might clean the floor the jack up the rear of the car and see if it still drips near the back of the engine or if it changes places now cause my initial thought was freeze plugs at the rear of the block but I could rule that out by jacking up the rear.
Anything else you guys can think of near the t-stat housing that could be leaking? I guess it could be the intake but think it would have to be both sides to fill both 'pockets'
 

Bronco2Fan

Member
Joined
Apr 16, 2020
Messages
160
Reaction score
135
Location
Texas
Whe mine was leakig, it was the hose with the special fitting on the firewall side. Slow leak ran down the hose and made it look like it was coming from somewhere else.
 
OP
OP
O

optionizerSS

Active Member
Joined
Apr 25, 2023
Messages
598
Reaction score
497
Location
Pittsburgh, PA
Went out in the car today to another cruise then back home. Went back down to the garage a few hours later and not a drop of AF by the t-stat and my plastic overflow bottle is still slightly above the full mark still
 
OP
OP
O

optionizerSS

Active Member
Joined
Apr 25, 2023
Messages
598
Reaction score
497
Location
Pittsburgh, PA
I'm confused. Gonna check it over again today but still dry as can be the other night. Seems like the car has to sit for at least 3 or 4 days to see any leaking. If you drive it at least every other day then no leaks. Weird. I'll take pics today to show exactly where I was seeing it but it's behind the timing cover on the block on each side of the distributor. There are like 2 'wells' there that are filling up. My guess is it's the intake gaskets leaking on each side. Might see if I can rent a pressure tester from Auto Zone Monday
 

Latest posts

Forum statistics

Threads
77,435
Messages
1,502,107
Members
14,917
Latest member
virocanah

Members online

Top