UhOh...It started with a bad MAF sensor

[wvtuff]

then the water pump started leaking out of the weep hole. I bought the MAF first driving the Explorer ('96 4.0) to the parts store so I could change in the lot and get the exchange. I filled the radiator with water before I left but most leaked out. The temp guage arose to about 3/4 of the way to red on the way home. Last week I had bought an OBD scanner to check the MAF problem and it now tells me that #4 cylinder was misfiring. When I pulled the plug, the electrode was completely gone and the tip of the plug looked rusty....not good. I put in a new plug and still got a reading for #4 misfire. I pulled the plug and I could see a few water droplets (I think) on it. I put in a new one and switched plug wires hoping that it was fuel droplets instead. I started it and walked to the back of the truck to look at the exhaust. My worst fears. Water was blowing out the exhaust.......sigh, now I'm depressed. I'm thinking either bad head gasket, head bolts not tourqed, cracked head or cracked block. Anything I'm missing? What if it's the block and can't be repaired? Where do I get a new block and or engine? Think i can fix this for under 3 g's?

 

[adale]

Water blowing out your exhaust is not unusal as water is a by product of most internal combustion. If there is a steady stream of water then you have got real problems, but just a few drops is ok. My 4.0 lost about a pint of water every 1000 miles, took it to the dealer and they said they could not find a problem, while it was under warranty. Found all the intake bolts loose and two head bolts at about 40lbs on the passenger side , tightened them up and wadda ya know, water loss stopped! Be careful checking and retorqueing the head bolts. As for your #4 plug, have you checked to see if the plug is even firing. I have never seen this problem on a truck with a coil pack, but I have seen it on a V8 ford with a distributor. The cap had two burnt contacts on the inside causing the plugs to never fire and they were always wet with gas. Even if you water pump is leaking like a seeve you should still not loose that much water. Do you have water in you oil? If the vehicle is running, open the radiator cap, WHILE THE ENGINE IS COLD!!!!, and look to see any big bubbles, don't laugh, if you have blown a head gasket the air has to go somewhere. Sorry for the long speech!?!

 

[wvtuff]

The water is coming out of the exhaust more than normal

Not a steady stream but more like steady drops and when I step on the gas it blows out the back enough to leave about a 2 sq. ft. wet spot on the driveway. In other words, more than normal. today I'll check the intake and head bolts to see if they are up to specs. I did check to see if the plug had spark by removing it and bumping the engine over (it sparked from the plug threads to the truck body) but I'm going to check the cost of a calibrated ignition tester today and possibly get one to be sure. I forgot to mention the oil....there is no water in the oil at all and that's one thing that's confusing. Maybe all the water is blowing out the exhaust possibly? Seems possible if it's coming from a head gasket or loose head bolts. I will check the bubbles in the radiator like you suggest. Thanks for the reply. I'll post what I find later. Thanks again.

 

[Brain]

Is this on your '91? I just got through (yesterday) replacing a cracked head on my '91 XLT, and it had some of the same symptoms as you are describing. I got a used low-milage head off of an '96 Aerostar (wrecked in rear) from the junkyard for $20. The head gasket set (including 2 head gaskets, lower intake, both upper intakes, two valve cover gaskets, two exhaust header gaskets, 12 valve stem seals, and several others) from Fel-Pro for just over $100. My head problem was so bad that it had blown a long crack in the plastic side tank of the radiator (from the steam), so if your radiator is still good you don't need to add that extra $125. A head bolt set (can't reuse TTY bolts) cost about $40 for a complete set. So a minimum cost would be somewhere around $300-350 (I added in some for degreaser, valve spring compressor, acetone, etc.).

When I bought this Explorer, it had a large seam torn in the radiator (on the front where you couldn't see it), and I was told it just had a bad radiator. Well, long story short, the radiator went bad because of the cracked head. My driver's side head had cracks between the valves in the #6 and #4 cylinders (front and back, but the middle one was OK), and the passenger side was all OK.

There are three places where this head tends to crack. A crack between the valves on the cylinder side will allow coolant into the engine as well as pressurize the coolant system (like you and I had/have). A crack in the oil drainback passage will allow coolant and oil to mix. A crack in the valve spring seat will allow oil into the intake/exhaust, so blue smoke comes out. This blue smoke can also be from other sources of oil-burn (bad valve stem seals, PCV valve, oil-overfill, etc.).

You asked if YOU could fix this for under 3g's, so I'm assuming that you are doing the work yourself and not paying someone else to do/warranty it for X amount of miles. It is pretty labor intensive, as everything basically comes out of the engine compartment or pushed aside (like the A/C compressor, power steering pump, etc.), and the block and heads have to be meticulously prepped/cleaned.

Since everything had to come out, it's a great time to replace things like sprak plugs, plug wires, heater hoses, etc..BTW, here's a link to know more about the heads and what years/vehicles are compatable (anything with a T will work, but the 93TM casting is lees problematic from what I've gathered):
http://www.therangerstation.com/tech_library/40rebuild.htm

here's a bit more:
http://www.therangerstation.com/tech_library/40Problems.htm