352 COOLANT LEAK

rider307g · Post by **rider307g** » February 10, 2009, 1:35 pm

I was just running around town and noticed a leak. I crawled underneath and it is on the passenger side at the rear of the block, dripping down the block and front of the transmission. I had hoped it was a coolant line but have not had the time to get in there and check. I was cruising through a thread and someone referred to a similar leak and said it was a cracked block. Anyone have this happen to them and what should I look for? If the block is cracked, is it now junk?

ICEMAN6166 · Post by **ICEMAN6166** » February 10, 2009, 1:47 pm

might be a freeze plug rusting out.

cracke blocks are a crapshoot, have seen some fixed and work for many years, others not.

cast iron welding requires preheating and nickle rod.

jwh f-100 · Post by **jwh f-100** » February 10, 2009, 2:00 pm

I would suggest you buy or borrow a pressure tester. Pump it up to the same amount stamped on your radiator cap. It will let you dig around on a nice cool engine.

Slick Fan · Post by **Slick Fan** » February 10, 2009, 2:01 pm

I would suspect a rusted freeze plug too, been there a couple times.

rider307g · Post by **rider307g** » February 10, 2009, 2:10 pm

Thanks for all of your advice, I freaked out thinking the block was junk. Next step, digging into it. Good thing I like wrenching

blackagatha · Post by **blackagatha** » February 10, 2009, 9:36 pm

my money is on the plugs too.

Shortly after I rebuilt the 390, most or all of the plugs were seeping a little. I put some of that aluma seal crap in and they dried up pretty good. they might still weep a little, but not enough to concern me.

These were fresh brass plugs with some sort of yellow sealant, professionally installed. My guess is that he didnt machine the bores. Ya know it seems to me there may have even been a couple of rubber plugs when I got the motor.... No wonder it leaks.

If I have it to do again, I'll probably get the screw-in plugs installed. Maybe I'll get that done if and when I go 442 and crossbolt the block.

R Pope · Post by **R Pope** » February 11, 2009, 10:10 am

Climb in the engine compartment and check the back of the intake gasket. There's a little tab hanging out with a slot in it. It diverts any leak from the head/manifold gasket out onto the ground to keep it out of the intake port. If that's what's leaking you just have to pull the intake and put in a new gasket set.

FORDBOYpete · Post by **FORDBOYpete** » February 11, 2009, 9:21 pm

rider,

If it turns out to be a welch plug, which is a common problem, replace them all when you do it.
And if you can, go back with "marine welch plugs as they are brass & do not rust through like steel do.
FBp

Astrowing · Post by **Astrowing** » February 11, 2009, 10:19 pm

The freeze plugs on my 351C starting seeping when it was about 10 years old (at the time). Replaced them all after that started.

greenindian · Post by **greenindian** » November 25, 2009, 4:02 pm

I'm noticing coolant too coming of my 352 near the rear to passenger's side of the motor. Can freeze plugs be put in with the motor in or should the motor be pulled to do this?

ICEMAN6166 · Post by **ICEMAN6166** » November 25, 2009, 4:24 pm

they can be done with the engine in.
its of course easier with it out or with the exhaust manifolds off.

Alan Mclennan · Post by **Alan Mclennan** » November 25, 2009, 4:28 pm

These welch ( freeze ) plugs seem to be giving a few of us some trouble lately, I wounder if there is a common reason?, the freeze plug reasoning is new to me as we dont really have that problem! and our coolant is called anti boil!. I was told by the radiator shop not to run the modern coolant in Lenore as she doesnt have any Aluminium contacting the coolant, all it needs is a rust inhibiter ie; soluble oil.
FBP, what is the reason for having those plugs?, I was always led to believe they were there to aid in the casting of the block or more so to remove the casting sand!

Roger Carter · Post by **Roger Carter** » November 26, 2009, 3:17 pm

Alan Mclennan wrote:These welch ( freeze ) plugs seem to be giving a few of us some trouble lately, I wounder if there is a common reason?, the freeze plug reasoning is new to me as we dont really have that problem! and our coolant is called anti boil!. I was told by the radiator shop not to run the modern coolant in Lenore as she doesnt have any Aluminium contacting the coolant, all it needs is a rust inhibiter ie; soluble oil.
FBP, what is the reason for having those plugs?, I was always led to believe they were there to aid in the casting of the block or more so to remove the casting sand!

Alan,
You are correct. The purpose of the holes is to allow for the removal of the casting sand from inside the block. The machining and installation of a welsh plug was the factory's way of plugging the core holes.
Some Ford performance engines, (427, Boss 429, Boss 302), had threaded pipe plugs installed in the sides of the block, instead of the welsh plugs. The claim was that the core holes were weak points and the threaded plugs offered a stronger fix than the welsh plugs.

Roger Carter

352 COOLANT LEAK

352 COOLANT LEAK

352 coolant leak