I have a '99 F-250 Super Duty (5.4L) with 263,000 miles on it. It developed a pinhole in the LS cylinder head right below the thermostat housing, causing a coolant leak. After sticking it with a screwdriver, I ended up with a 1/2" hole!! Has anyone ever encountered this? I can't even drill & tap it as it is near the top of the head where there is a bend in the casting. I really don't want to pull the head off - is there some "super epoxy that will stand up to the coolant temperature/pressure? Thanks.

 

Maybe get someone to Tig weld a patch on it.
I would say it was corrosion from not changing coolant ???????????
A 1/2 inch hole is to big for jb -weld
Don't forget if you have someone weld it to disconnect the battery and isolate the pcm grounds also or you will blow up the pcm.
Rich

 

I'll have to agree with Fortyfords. It sounds like your coolant became acidic.

 

OK - I went the JB Weld route. I hammered out a 1/16" piece of aluminum to fit the corners and to cover the hole by 1/2" on all sides. I sanded the area and wiped it down with acetone, then JB'd the whole thing. If this doesn't work, then I might use an expanding rubber plug. I'm afraid of what the heat might do to the head if I have it tig'd, given the thin wall thickness. I'll know by tomorrow!!

 

For what it's worth, I have had good luck using JB weld on my 1941 Ford 9N tractor. My cylinder block developed a 1/2" crack at the water jacket. I ground v-groove at the crack and applied JB weld. It's held up for 3 years now... Hope it works for you.

 

All is well with the repair. I have about 50 miles on it with no signs of leakage. While I had the opportunity, I replaced the thermostat (original!!), o-ring, tensioner bearing (got it at Grainger for $6.76), belt & coolant. My owner's manual says "if it has orange coolant, use the long-life stuff; if it has green coolant, use the regular stuff" (not verbatim). I asked my local dealer and they said the same thing. GAR! Being that my coolant was orangish-green, I flushed the whole thing and put in the green stuff. I'm keeping my fingers crossed!!

 

I heard about this as a known issue... coolant flow past that point erodes the metal, and it leaks.

I have NO idea if there is a fix or updated head, I only know what I've read on this site

art k.

 

How is your repair holding up? Interested in knowing!

 

I had this happen on my 99 V10. Ford repaired using a sleeve and epoxy in the coolent passage. There were casting issues on the heads.

 

So far, so good! I put around 300 miles on it with some heavy hauling and no leaks!! I went bananas preparing the surface, which I guess paid off. I have some pictures of it and I'll have them up here as soon as I remember how to do it! A while ago, I repaired a broken 442 emblem stud with JB Weld (then threaded it with the speed nut!) and have sworn by it ever since. It has a working temperature of 600 degrees F, so 200 degrees F is a walk in the park.

Bear1911 - Is the sleeve to which you are referring a V10-specific item? Would one be able to get this right from Ford parts?

Brad

 

You can never prepare the surface too much - unless, of course, you break through to the other side

 

I don't know if it is specific to the V10, the shop manager said this was a known issue with the heads, so my guess is that it could have affected the v8 also. It was warranty work. I do not have a part number.

 

Here are the pics. Unfortunately, I took the picture of the actual hole with my phone.

http://img26.imageshack.us/img26/5316/dsc015443vn.jpg

http://img504.imageshack.us/img504/1544/dsc015461kq.jpg

http://img469.imageshack.us/img469/4538/dsc014091rg.jpg

http://img469.imageshack.us/img469/259/dsc013951hb.jpg

Images changed to links (it's a little nicer for the dial-up users. -Beast12

 

Well, it's been almost 3 years and 13,000 miles since fixing my cylinder head with J-B Weld and it's holding up great! This stuff is unbelievable!!

 

Thats crazy!!! My truck has 130,000 on it. I hope mine lasts as long as yours. What kind of repairs have you had to do? Transmission?