351W water leak behind timing cover

[salesco]

has anyone had this problem? is there a water jacket inside the timing cover? water seems to be leaking from the gasket between the timing cover and the block not the water pump gasket. ford crete motor only 1500 miles. help!

[GREENSNAKE]

Try to re- tighten the bolts on the timing cover and the water pump.They will lossen up after the first few hundred miles on a fresh engine . Lonny

[Rick Parker]

As stated, retighten the entire group of bolts that secure the front cover to the block. Included are 4 long bolts that effectively secure the coolant passages from the pump to the front cover and the front cover to the block. After this you might consider using a small amount of cooling system stop leak, just don't go overboard; consider it insurance for future or present minor leaks. To visualize the passages you are attempting to seal, look at a bare block or a bare front cover, the bolts extent through the pump, through the front cover and into the block.

[Woodz428]

There's really only 2 possibilities, one, a hole has eroded through the timing cover( the pump uses the cover as it's backing) or the 2 big passages have a bad gasket. If it is a pretty good leak, I'd pull it off and inspect. If it is a minor bit, tightening may seal it. If it does, I'd still pull it at the earliest convenient time, it probably won't stay sealed permanently.

[Tongue Pirate]

Mine is a 64' block & there was quite a bit of corrosion around that front flg. I sealed it up & torqued everything down originally. Haven't had a problem. With a new crate I can't see any reason why there should be anything other than a bad gasket or incorrect torque unless there is something unforseen like a defect in either of the mounting faces or joining parts

[trularin]

Only once, turning out to be a bad cover where the water pump bolted on.

Got a new one and pulled the engine completely appart to check and clean everything.

Water in the oil is not a good thing.

BTW, this was not on my Cobra, but on my mustang.

[w-lewis]

My 351W crate motor has same problem, a very slight leak that allows a small amount to coolant to collect on top on block, behind the front engine cover, just below the themostat housing. I thought it was in expansion tank and changed it to new tank that uses o rings instead of gasket for themostat housing. After couple of weeks with new tank/o rings, leak reappeared. Have tightened all water pump and manifold bolts. Odd thing is leak will appear after a couple weeks of car sitting up, whereas after driving car and even after cool down, all is dry. I now have dye in system to try to identify leak. Any ideas?
Walter

[salesco]

Tried bars leak, leak is gone for now. seemed to be top right of timeing cover where it meets the block. i didnt think there was a water jacket there

[Wammy]

W-Lewis-

I would try another thermostat housing. Had the same problem, bought a genuine Ford housing and new gaskets and took my time putting it on. I had some aftermarket on before, no problems since.

Good Luck,

James

[HI Cobra]

w-lewis,

I had a leak like that on mine a while back. Pulled the thermostat housing,
replaced the gasket and filed a casting ridge on the intake to flatten it. So
far so good. I was getting coolant in the same location you described.

[w-lewis]

My original expansion tank was a beautiful, custom made "427 look alike" tank, made for my 351W. It utilized an original Ford thermostat housing that used factory gaskets. The tank was somewhat fragile as you could not press down on coolant cap without supporting underside of the tank with your other hand for fear the neck to tank weld could break. I removed tank several times and replaced gasket, but leak always returned. Odd thing is, it always came back after a week or two, usually while car sat up. Assumming the leak originated from a pinhole or the tank neck's weld, I replaced it with a sturdy welded aluminum tank from Finishline that utilizes O rings between the thermostat housing and mounting bracket and a conventional Ford gasket between the bracket and manifold. The new tank did not leak untill several weeks after installation, the last few weeks while the car sat idle. I've not put dye in the coolant, hoping to give me some clue as to where it's coming from.

[kidcobra]

w-lewis,
If you are still having the leak do like i did with mine.
I had the same style leak on my 351 and it did the same as yours did. just show up after it had been sitting for a spell. All I did was drive it for the day parked it and opened the hood. Every time I went out to the garage for a smoke I would look at that area with my little $3 mirror and a flash light till I could see where it was coming from. What it ended up being was the groove on the finishline housing was just a little bit to deep and the temp would make the housing swell up and it would seal but when it started cooling off good it would start leaking ever so slowly. Just enough to make you pull your hair out. I ended up having a buddy machine the housing down just a hair and put it back on with new o-ring and nothing else and walla no more leak.
Matt

[w-lewis]

Matt,
That makes a lot of sense. Since the leak is so small, I'm not going to do anything now, but next time the car will be down for awhile, I'll give that a try. Many thanks for the idea.
Walter

[kidcobra]

Walter it took me about 6 months to finally have timeto fix the leak and I just kept wipping the puddle up before i drove it.
Good luck.
Matt

[Rick Parker]

After this you might consider using a small amount of cooling system stop leak, just don't go overboard; consider it insurance for future or present minor leaks.

........We're not flying the President over burning oil.