2003 E250 5.4l V8 leaking coolant somewhere
 

I've got a 2003 E250 cargo van with a 5.4L V8 that I haul sound equipment in. It's been great for the 1st 10 months I've had it. A few months ago I had to replace the thermostat since it overheated a few times. It had been leaking coolant very slowly but I never saw where, there are no obvious wet spots on the ground or on the chassis.

Lately though it's going thru more coolant (I had a "coolant exchange" done at pep boys down the street. They didn't do a pressure test though (said they did one at the operating pressure of the engine. wtf), I replaced all 8 plugs about a week before this. Apparently these were the 1st plugs ever put in, they had plenty of wear on them for 120K miles.

Right now it's eating coolant, I don't know where it's going. I've been fortunate enough to marry into a family of mechanics and just want to see what I'm about to get into with this. Everything points to head gasket (no water on the oil cap or in ANY of the cylinders though), or cracked heads (these use aluminum heads right?). I had a 97 that cracked and water would piss out the top by the #7 cylinder, why did I buy another ford?

Any ideas?

yes they are aluminum heads on the 5.4l. you said no water in any of the cylinders?? How did you find that out without pulling the heads off?? When you pull the dipstick to check the oil any milky color on the dipstick?? I know the early 5.4l had a coolant line under the intake manifold that goes to the back of the engine, have you jumped under it and checked by the transmission bell houseing for coolant or coolant resiude?? If that line is leaking it will normally seep out the bell houseing of the tranny. The water pump also has a weep hole on top of it if you see coolant in the weep hole the water pump is going out and may be dumping coolant. What makes you think it is a head gasket??

I don't know if it is a head gasket, but I still don't know why it would run rough at operating temp and perfect when cold. I'll definitly take a look at those spots for leakage (after that's why I'm posting), be patient with me though I'm a bit of a newb. At 36 I've decided to really learn about fixing vehicles myself rather than being the victim of whatever comes along.

Thanx again for your help, I'll be picking at this problem this weekend. I wouldn't be suprised if it's a cracked header or head gasket. But there is no coolant on the dipstick or any plugs, more to come...

no problem keep us (the forum) updated and we will get you through it. You may have to do a cylinder compression test and leak down test to verifiy it does not have a blown head gasket. How hot did it get?? Red line on the temp gauge?? Compression tests are fairly easy to do but you have to pull spark plugs to do it. The 5.4l ford engine is great for the most part they normally live 200k + miles if maintained.

The incident that made me change the thermostat was when it got all the way into the red. I let it cool and restarted it and I could tell when the thermostat opened up (when down to the center of normal). The temp gauge read hot for about 2 sec then settled quickly into the normal range.

More later...

o.k. how long was it operating in the red?? You also said it runs rough when warm?? Any check engine lights?? I can now see why you think it may be a head gasket.

It wasn't long in the red, maybe less than 30sec. I replaced the thermostat in feb and the problem seemed to go away. Lately though I've been checking it almost daily. At this point it will eat about a gallon per 400 miles. No white smoke.

I have the air intake out right now and am looking for leaks (signs of coolant, the engine is cold now). The 2 hoses from the bottom of the radiator are fine, reservior to the juction (engine intake, heater core, radiator bottom) is ok.

I'll get a pressure test done on it this week and see where it's going if possible. Yeah the check engine light is on, it's been on (code say something about oxygen sensor) since I bought it last year.

I know this isn't really the most helpful, maybe someone can learn from this. more later

a buddy just had his 97 vic have the tube for the heater i think , under the intake go bad and cause the dain thing to overheat just as he pulled into town . it eventually within maybe 2 miles cracked the intake too . he pulled over and shut it off too see what was up , couldnt see anything as it was a hidden leak . well now an engine change later ....................................:-X15

If you're loosing coolant but can't find any leaks and aren't getting the other symptoms of a head gasket (milky residue on dipstik or oil cap and constant smoke out exhaust), check your intake manifold gasket. They are prone to fail at the front water passages right at the crossover tube.

I just went through this (well I'm still going through it I plan to button it back up tonight haha) and I had similar problems with water dissapearing (although mine never overheated...) turned out to be the intake gasket. Reach under the manifold there with a finger or two and see if they come back out covered in black soot, thats the sign you need gaskets.

I just posted an update on my thread (2v 5.4l smoking) check it out, it may help you with your problem.