Mysterious Coolant Leak
Thread Starter
Cruising
Joined: Jul 2014
Posts: 12
Likes: 0
Mysterious Coolant Leak
Hey guys I got a weird coolant leak and would love some feedback on how to tackle it..
I have a 1981 350 4 speed stock except for exhaust. It leaks about a cup of coolant a week and I've been trying to figure out from where. At first it looked like an oil leak from the rear main cause it was dripping in the same spot, but it's definitely coolant. It's not any of the hoses and isn't the intake gasket. Everything is tight and dry around those areas. It seems to be coming from lower. While under there I noticed spots of coolant on the bell housing, driver side engine mount (but not the other), driver side head is a little sweaty, pass head is dry, starter, oil filter, and a few other spots.
I'm thinking maybe it's an external leak from the head gasket... if so, how would i go about finding out for sure before tearing the motor apart? Also, are there any other areas that it could be leaking from?
A friend who took a blind guess believed it might be a freeze plug. I'm thinking it might be warped/cracked head(s).
It performs very well and has no other leaks or issues.
Thanks in advance everyone.
I have a 1981 350 4 speed stock except for exhaust. It leaks about a cup of coolant a week and I've been trying to figure out from where. At first it looked like an oil leak from the rear main cause it was dripping in the same spot, but it's definitely coolant. It's not any of the hoses and isn't the intake gasket. Everything is tight and dry around those areas. It seems to be coming from lower. While under there I noticed spots of coolant on the bell housing, driver side engine mount (but not the other), driver side head is a little sweaty, pass head is dry, starter, oil filter, and a few other spots.
I'm thinking maybe it's an external leak from the head gasket... if so, how would i go about finding out for sure before tearing the motor apart? Also, are there any other areas that it could be leaking from?
A friend who took a blind guess believed it might be a freeze plug. I'm thinking it might be warped/cracked head(s).
It performs very well and has no other leaks or issues.
Thanks in advance everyone.
Burning Brakes
Joined: Apr 2008
Posts: 1,222
Likes: 93
From: shelbyville West Michigan
could be a freeze plug, or a head gasket. if it's stock, the factory head gaskets would be suspect after 35 years. There are other things it could be, but those would be the first things I checked.
You need to do a radiator pressure test. HF sells the kit, or any shop could do it for you. Sears sells the mityvac radiator test set on sale off and on recently for cheap ($29.99). pressurize the system and look for leaks. use baby powder around the suspect areas to get a better view.
You need to do a radiator pressure test. HF sells the kit, or any shop could do it for you. Sears sells the mityvac radiator test set on sale off and on recently for cheap ($29.99). pressurize the system and look for leaks. use baby powder around the suspect areas to get a better view.
Melting Slicks
Joined: Jul 2006
Posts: 2,292
Likes: 494
From: Salmon Arm, BC
Check the bottom of the water pump.....there's a hole that can allow coolant to leak out, (You'll probably need a mirror) and the wind moves it back to the other parts of the engine.
Also have a look at the lower rad hose, heater hoses, and the water pump bolts
Also have a look at the lower rad hose, heater hoses, and the water pump bolts
Racer
Joined: Nov 2011
Posts: 374
Likes: 21
From: Charleston SC
Mine sat in the garage for a couple weeks and I discovered it leaking from somewhere I couldn't locate. Looked everywhere. I have breakfast about every morning with several friends (car guys) and one morning one of them mentioned that his "52 pickup was leaking all over the floor and commented: "I've never seen condensation so bad." Made a beeline to Lowes. One de-humidifier later, I've cured the leaking Vette. Just saying. Have a wonnerful week, Bill
