I am new to the forum. I have owned Fords for many years and I hate to even think of how many F 150s. I am hoping to glean from the experiences of the rest of you, a little help on a problem I'm having with a 1998 F 150 with a 5.4.
I furnish this truck to my Son as transportation for he and his family as he attends College. He brought it home and got mom's car because he says it is blowing out coolant. It has not been overheated and the temp guage stays normal. He had the radiator drained and refilled with new coolant. The problem occured afterward. I have had it in two different shops. They tell me they drive it and cannot get it to blow any water. They also tell me it may have a blown head gasket, or cracked head. No steam out the tailpipe, no water in the oil, no oil in the water????? They also tell me it would be cheaper to buy a used engine. It has 137,000 miles. Any ideas as to why it would blow water, then stop doing it?

 

Strange problem, I would flush it myself and make sure there wasn't air trapped - (the air might be working itself out) The proper way to flush is unbolting the block plug after draining the radiator. Pulling the top hose on the refill and fill until water starts to come out of the top hose, no air that way..
I would also replace thermostat.

Good Luck

 

I had a 93 F150 with the 302 and approx. 187,000 miles and started doing this. The only time it would happen though was when the engine temp got near the 210-220 area(under a load) it turned out to be a hair line crack in one of the heads. I found this out because I decided to replace the head gaskets as recommended for the "blowing antifreeze" problem... During the inspect of my heads(magnafluxing) they found a minute crack in one of them. I replaced it with a salvage yard part and resolved the problem. Seems like the cost of repair was around 400 bucks. BoB

 

I appreciate the replies and sound advice. I do believe there is air trapped. Possibly from the radiator being drained and refilled. I am hiring the work done (not really up to it anymore). The guy called saying he couldn't find anything wrong. I went to pick it up this morning and he had driven it again, and it puked out coolant. I asked him to flush the system and replace the radiator and heater core if he determined it was needed. I hope he knows about the block plug. I didn't! Where is it located? Maybe I'll call him and inform him. Am I to understand this is something easily removeable and not a freeze plug?

 

The block plug is on the drivers side directly in line with the exhaust to manifold connection. You have to remove drivers side tire and inner fender-well to access easily - it takes a allen wrench to remove. Simple to remove and no , it's NOT a freeze plug (there next to it and on the other side aswell) This plug is there to drain the block and is in the shop repair manual - specific 4.6 stroked(5.4L) -non stroked blocks - same locations. Standard flushing procedure - If a shop flushed it previously , it seams like they would know this. With a shop hoist, you can get at it without tire/wheelwell removal.

This is the flawless way to flush and works very well - when filling and the top hose off , you can here the water slowly work it's way through your motor until full - then it creeps out the top hose.

NO air No problems and 100% flushed.

 

Thanks for the heads up on the plug. I will make sure it gets done. I never knew it was there. I don't have a shop manual. I usually never do anything other than oil changes etc. anymore.

 

No problem, let us know how it works out

All manuals on ebay's site - dirt cheap and model/year specific.

 

When I flushed my cooling system last summer I too looked for the plugs. I fiound the one on the drivers side but the passengers side plug is behind the starter. I didn't pull the plugs I just spent extra time carefully flushing the system.
Both plugs have to be pulled to get the system empty. Each side of the block is independant from the other. If you only remove the drivers side pulg only that side will drain. The other side will still be holding coolant.

When I refilled the system I filled it as far as I could, ran it till it heated up and opened the thermostat, then carefully cracked loose the upper radiator hose and pulled it back so I could bleed the air out. Any residual air will "burp" itself out as you drive.
And don't forget to use distilled water, not tap water. Distilled water has no minerals in it to cause rust or clog the radiator and heater. or it's easier to use the pre-mixed coolant.

 

[QUOTE=Iggy]When I flushed my cooling system last summer I too looked for the plugs. I fiound the one on the drivers side but the passengers side plug is behind the starter. I didn't pull the plugs I just spent extra time carefully flushing the system.
Both plugs have to be pulled to get the system empty. Each side of the block is independant from the other. If you only remove the drivers side pulg only that side will drain. The other side will still be holding coolant.

Holy #@$%#$ Iggy!!! I didn't know there were two!! Sure enough. That's just great , all these years lop siding my motor lol. I learn something all the time here. I know where all my sludge is hanging out - geezzz..
I probably didn't hurt it much. I pretty much do it the same way as you , I add a chemical flush aswell after the water turns clear and I'll take my method on the filling part over yours - don't wanna risk it if I don't have to - I'll follow the manual there , never a problem anyhow(knock on wood)..

I'll pull the starter next time (it's getting frickin rusty - Michigan rds.) if I have to in order to get to that other block plug. Rounding 200 thousand miles and curious to see what comes out of the other side now- maybe some tools I lost over the years

Thanx for posting that..

 

This may sound funny but I had a similar problem after changing out the thermostat. I found out there is a small hole in the thermostat the burps out the air on start up and heat up. If it is not in the 3 o'clock or 6 o'clock position, the air can build up and pukes out as soon as the thermostat opens. This sudden rush of air gets into the overflow and will surpass the pressure of the cap. Then the fluid will gush out. It only happens on initial start up. Once up to temp then you can go all day without a problem. That is why it is so hard to duplicate by the service center.
The first thing is to get a genuine Ford thermostat. Then install it with the air hole in the 3 or 6 o'clock position. See if that helps. It can't hurt.
It fixed my problem.
Good luck.

 

The passengers side drain plug is actually behind a mounting bracket that attaches to the starter. If I had the time and ambition I could have pulled the bracket and gotten to the plug...but I didn't.
If the manufacturers used a drain plug like my marine engine has it would be a snap. One turn of a wrench and the plug is open. No hassels.

As for lost ools, I seem to drop things down through the intake manifold and lost in the valley beween cylinder banks. Must be some creature in there that sucks them up cause I sure can't find them.

 

there are two ways that you may be able to determine that you have a combustion leak (i.e. cracked head or bad head gasket)

1. Go to NAPA and get the kit to check for head and block combution leaks. It has a tube filled with liquid that you place over the coolant fill opening. If carbon dioxide is present the fluid will change colors. In your case you would need to let the vehicle idle until quite warm since it only seems to puke when hot and under load. I would block the air flow through the radiator and let the engine idle with the cap off.

2. The other technique is cheaper and maybe more effective. Disconnect the hose that goes to the overflow bottle and replace it with a longer hose. Fill a two liter clear bottle with water. Place the hose in the bottle. Start the engine, trapped air will bubble out and eventually stop. If there is a combustion leak the bubbles will not stop or will resume bubbling after the initial air is purged. This may take sometime - you will need to be patient.

 

There's one other way to tell, actually two ways.
One, is to use a cooling system pressure tester. The tester had a gauge on top. You pressurize the system and watch to see if the gauge looses pressure. if it does then you start looking for external leaks. if none are found then it must be internal.
The second is a leakdown test. A special tool with two gauges is attached to the spark plug hole. Compressed air is injected into that cylinder and sealed off by a valve. And as before you watch the gauge to se it pressure drops. Not only will this check for coolent leaks, blown gaskets, or cracked block/head, it alos checks your piston rings and valves.

 

This has to be the best/most informed group I have run across! I called the mech and told him about the drain plugs. He already knew, but somehow I doubt he used them. He found a bad radiator, as I expected and has a new one ordered. Not sure what it will cost. This truck has the factory towing package, thus a larger radiator I assume. I didn't ask about the heater core, but I've already told him to replace it too, if at all suspicious. This shop is primarily a radiator shop, and came highly recommended, so maybe they know what they are doing. If the problem is not solved I will try the methods of determining if it is a compression leak that I've learned here. I will replace the engine if necessary, but of course as a last resort. I've been told by several folks that a good low mileage used engine is the way to go rather than tearing the heads off this one with this many miles. What is your feelings on this? I already checked and it seems one can be had for about $1,200.00 +- and labor to change them would run about 4-500.00.

 

my methods are a lot cheaper