My 302 has developed a substantial coolant leak. It appears to be dripping down where the engine meets the tranny bellhousing. It leaks before and after the thermostat has opened, and leaves a spot about the size of a cd overnight. Any ideas?

 

The leak is very likely coming from where the heater hoses go into the heater connections on your truck's firewall.

To locate the leak, run the truck until the engine warms up then turn it off. Residual heat causes the coolant system to pressurize and you should be able to find that leak.

Lou Braun

 

Well I checked all the heater hoses and connections and that is not the problem. It seems to be coming from the backside of the block somewhere. There is no pooling in the lower intake, so its not the sensors; the freeze plug in the head is fine also. My only other guess is the intake or possibly a head gasket or freeze plug within the bellhousing. I noticed that when Im parked at school with the front end lower than the rear, it doesnt leak. And with the front end higher than the rear, it leaks a lot more. Im gunna pull the upper this weekend and see what I can find. Any other ideas?

 

isn't there a freeze plug or two on the back side of the block?

 

I had leaks at back of block and finally found the front cover was leaking at the bottom edges and certain times would runback along top of pan gasket and off the back of the engine at rear seal area. Couldn't see anything anywhere along the engine till it reached the rear of the block. Just a thought.

 

just had a leak in the same area, turned out to be the timing chain cover gasket. leaked all the way to the back and hit the ground between the bell housing and engine.

 

I checked the timing cover and there are no signs of leaking there. I assume a leaking timing cover would also drip coolant from the sump of the oil pan, in which there was none. I checked it again today and it's dripping from the thin plate between the engine and the bellhousing, towards the passenger side. I also looked up some pictures of the 302 and did not find any freeze plugs on the back of the block within the bellhousing. I did notice the milkshake gunk under the oil fill cap and pcv valve, but none in the oil or on the dipstick. The intake is coming off tomorrow so wish me luck.

 

Really suggest that you locate the source of the leak for sure before starting work - just a suggestion - I have done too much work in vain to start a major operation without being sure what the problem was. Good luck.

 

Do you have a coolant line going to the throttle body? Mine has one line that comes of the back. It's a diffrent motor but it might have the same thing.

 

Let us know what it is...will ya? I have the same thing

 

That goes for me too.

 

So after pulling the upper I found a small sensor behind the intake. It appeared to be in a water passage and it was wet around it, so I pulled it and taped it up. I also torqued down the lower intake, but the problem persists. My only other idea is a head gasket, which will take all weekend. Tomorrow I might run it to the shop and have it pressure checked or dyed, and hopefully this will yield the problem. I'll post back with the results.