Engine Small Coolant Leak

StadEMS3

Dirt-Old 20+Year Member
Jun 19, 2003
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Mechanicsville, MD
I have a small coolant leak at the back of the engine above the starter. Maybe a drop every couple of seconds. Hoses look good, I can't see the freeze plugs, but I'm thinking head gasket because I can see a little wetness by the back corner of the head. I just changed the oil and it looks good, not milky at all. The engine was rebuilt to a 331 in 2006 with only 9,000 miles driven on it. It has been running great.

What do you guys think about those radiator leak additives? Do they work?
 
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No additives!!! They won't work for long if at all. I'm gonna start sounding like a broken record here.... But what kind of intake gaskets are you using? You NEED a Steel core intake gasket. OEM's had Steel core i believe but those 1250, 1262 etc. WILL eventually leak. I thought i had a head gasket leak too at first. But you will probably find out its just the intake gasket.

Heres what i just went threw...My intake water crossover leaked inside the motor. I lucked out and caught it before the milkshake seized my motor.
http://www.stangnet.com/mustang-forums/threads/help-coffee-colored-oil.861520/
 
I have a small coolant leak at the back of the engine above the starter. Maybe a drop every couple of seconds. Hoses look good, I can't see the freeze plugs, but I'm thinking head gasket because I can see a little wetness by the back corner of the head. I just changed the oil and it looks good, not milky at all. The engine was rebuilt to a 331 in 2006 with only 9,000 miles driven on it. It has been running great.

What do you guys think about those radiator leak additives? Do they work?
 
The head gaskets in a Mustang don't typically leak from the water into the oil. Usually it blows from the combustion chamber to the water jacket, and eventually out the corner of the head in the fashion you described. It could also be the intake leaking at the back. The stock intake gaskets are just paper, no steel core or anything like that. If installed properly, they won't leak. Don't use any additives. They do more damage than good.

Kurt
 
Yeah what Kurt said....

Either way you've gotta take the intake off to get to the heads anyways. So if you see the leak evident in the intake then i would stop there. But if those gaskets look fine then keep digging till you find gold. :)
 
I think Autozone rents a coolant pressurization tool for free. It's a thingy that replaces your radiator cap with a hose on it. You pump up a hand pump to pressurize the coolant system with way more pressure than the stock cap holds in, and then you can go look to see where the coolant is squirting out of of.

Kurt
 
I think Autozone rents a coolant pressurization tool for free. It's a thingy that replaces your radiator cap with a hose on it. You pump up a hand pump to pressurize the coolant system with way more pressure than the stock cap holds in, and then you can go look to see where the coolant is squirting out of of.

Kurt
yup, and they rent the block testor too. grab the tools and leave your cash. bring it back when your done and it is zero strain on your wallet. just did it last month.
 
Those gaskets suck. $45 for gaskets with cork valley seals. What a crock. Just buy the over the counter Fel Pros. They are cheaper and better. Factory replacement Fel pro head gaskets work fine too.

Kurt
 
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Those gaskets suck. $45 for gaskets with cork valley seals. What a crock. Just buy the over the counter Fel Pros. They are cheaper and better. Factory replacement Fel pro head gaskets work fine too.

Kurt

Yeah i bought the Fel-Pros 1262s-3 and paid around $33 They are made be Fel-Pro anyways. Make sure they say s-3 though. My Gaskets came with cork ends. But i use a thick bead of Black RTV to seal my intake in the front and back and have never had an issue. I also use a thin amount of the RTV around the water ports on both sides of the gasket. I let it set overnight after assembly too. "Just to make sure" Its not a job i enjoy repeating.
 
1262s are for big ported heads. AFR165s use a stock size gasket. Spending the money on 1262s is a waste of money. This is all you need, and follow the directions they won't leak. The come with the original style rubber seals too.

http://shop.advanceautoparts.com/we...set-felpro_5781639-p?searchTerm=intake+gasket

I always buy a set of these along with my 1262 kit just to get the rubber seals, and I chuck the rest in the trash. Actually I get them for a 95' F150, because then I get a spare plenum gasket for my Holley Systemax, and then I chuck the rest..

Kurt
 
Yeah that would be sweet. Like the one piece oil pan gasket. That was a huge improvement to that multi piece cork and rubber puzzle that took 2 tubes of RTV to seal.

Kurt