Duncannon

Ok, so here goes; this is my first time posting so forgive me if i leave anything out.
My 1994 F150 5.0 efi EXT cab seems to be leaking coolant from one of the studs that connect the exhaust manifold to head (passenger side) it appears as though this only happens when the engine is cooling down, because i dont see any signs of the coolant running/dripping anywhere but straight down. The truck has approx 200K on the body and trans, however i was told the engine was rebuilt prior to my purchase when the odometer read something like 160k. - The temp guage seems to move slightly hotter than usual at highway speeds (in and around the N and O of the word NORMAL, when it would usually stay just before the N) the coolant will drip down from one of the bolts between cyl 2 & 3(?) And drip onto the starter/transcooler lines. I dont have any oil in coolant/coolant in the oil. Could this just be a simple fix with RTV and new bolts? Or is my head just trash at this point? Has anyone else had an issue like this? This is my daily driver so i would like to get this fixed ASAP, im somewhat competitant when it comes to working on engines but lack many pro tools like air compressors, impact stuff or a tap and die. Is this something i can fix with hand tools in a drive way or would i be better off taking it to a shop? If you were to ball park the price for a shop, what would that be?

Thanks in advance,
Duncan,

Steve83

No one can guess any price without knowing what's wrong, and where you are (the local market). The price in Nunavut would be different from the price in SF, CA, or in Bunkie, LA.

If you want to find out what's wrong, remove that bolt, and see if coolant pours out. If it does: yes, the head is trash, and no, you can't fix it with RTV or anything else. It would have to be replaced, and it would probably be cheaper to replace the rest of the engine at the same time (either reman or used).

It doesn't take air tools, an impact, or taps & dies to change or rebuild an engine - the first few I did were without any of those luxuries. Just a cheap box of sockets & a Haynes manual.

Duncannon

Thank you Steve88, i will get in there tomorrow and pull the bolt/manifold to see what happens. Fingers crossed, if this thing is toast I'll end up biting the bullet and Uber my way to a dealership.... as for location; Southern New Mexico. -not sure if anyone would know of the price for the fix, provided the head isn't toast...

Chris_1

iTrader: (1)

Impossible to fix a price but - it could be a bad head or a head gasket or something else. Worse case scenario you should be able to get it fixed properly for less than a thousand. Anything at a dealership will cost quite a bit more or be old and possibly present you with a lot of it's own problems. 1000.00 isn't going to get you very far at a dealership anyway, and it may not be that much to fix - that's just a guess at the high side.
Depends how good of shape the truck is in and how much you like it or don't. Worth getting an estimate at least.

Being in New Mexico I'm guessing it probably doesn't have any rust. Us guys up here where they put salt on the roads to melt the ice wouldn't think twice about throwing a new head or even a new motor at a truck without any rust.

Duncannon

Thanks Chris_1, yeah the truck is pretty rust free, if anything i would keep it as a project/dump run truck. Being in NM rust is rarely a problem but the dust, wind and sun will tear up a paint job quick. (Not that i give two $%&@s what this rig looks like.) The only reason i am holding out hope is i have some how managed to put roughly 20k on the motor with this leak, and the truck isnt throwing any codes but some egr related stuff. What is strange to me is, the coolant in the rad seems to disappear pretty quick, i havent found any in the oil, but whats even more stange is the overflow tank, seems to be staying around the same level. - signs of a hg issue, i know but like I said no coolant in the oil, no white exhaust, and the temp just seems to fluctuate on the cooler side of NORMAL (dummy gauge) but still slightly warmer than when i first bought the thing...

Duncannon

I should also mention; a few months ago i had been looking to make this thing more fuel efficient and i took a sawzall to the exhaust after the first cat and threw a cheapo cherry bomb and some 3inch pipe and ran it back to come out just before the rear tire. (I would later purchase a K&N intake, i have the MAF model... but doubt that would play into the issue) my thinking is; my jerry rigged exhaust job created significant vibration which may have dislodged and sealant previously applied when the motor was supposedly rebuilt... I dont know if the 5.0 exhaust studs go into the water jacket but i hear conflicting arguements.... does anyone happen to know if this would cause such a leak? Ill try and get some pics up tonight, so maybe you guys can get a better idea.

sdmartin65

Lower head bolts on 5.0 do go into water jacket and must be sealed on install. A couple of those or one leaking could look as though it's leaking at exhaust bolt. If it is for sure leaking at exhaust bolt seems like only a crack could cause that. I've used copper seal before for a similar problem and the stuff is a miracle in a bottle for block leaks.

Duncannon

BareBonesXL

People have driven vehicles with small persistent leaks for hundreds of thousands of miles. In your case, the head is doing its job, the engine runs well, the truck goes, so all you really have a is a leak that bothers you. You could just monitor its condition and keep topping off with coolant. Or try to fix it with some sealant and if it works live with the knowledge that your engine isn't perfect. You can spend a lot of time and money fixing something that doesn't need fixing.

I've heard that Ford Motor Company actually uses a form of stop-leak in the coolant system as part of normal manufacturing practice. They expect small leaks and add it for prevention, in their brand new engines. Many people hate it but Ford puts in from the start. At least that's what I've heard. They do talk about their own special Ford brand stop-leak powder though. You could even try that. Sealant on the bolt seems like a better idea though.

Just an alternative thought. Doesn't seem like you need to be in a big hurry.

Steve83

Although it's not helping economy, reliability, comfort, or emissions; it's not likely that your exhaust mod damaged the manifold bolt or head.

I don't remember specifically checking, but I don't think any head bolts go into the coolant journals. The service manual does NOT mention applying sealant to them, which would be necessary if they're exposed to coolant. If the leak is coming from a head bolt, the block is ruined. The disappearing coolant is probably evaporating around the hot exhaust manifold. The stagnant overflow is due to the same leak. Have you ever checked the coolant system with a pressure tester? Fill it as much as possible (at a heater core hose), then pressurize the cold engine & follow the drips forward & up.


(phone app link)

The factory temperature gauge is not a dummy - only oil pressure. The temperature gauge is effective & reasonably-accurate.

That chart is for later engines - not these smallblocks. But I've never seen or heard of powder in the coolant from the factory. Nor have I ever read or heard of anyone adding it to a reman. I've never put it in any of the engines I've rebuilt - at the Ford dealership, or anywhere else.