Hello To All,

Was driving my 1992, 3.0 and all of a sudden noticed temperature gauge go to extreme hot, steam from hood and engine stalls. Upon inspection, the heater hose blew out, and van does not start even the next day, plus I think the starter sound different (faster). Saw spark at plug wire, smell gas, and did a quick compression with my thumb on #1, and felt air.
Towed it to the mechanic and within 5-10 minutes told me it was a cracked engine, I was not there but he stated he did a compression test.
Is he correct, or can it be a timing chain problem?

Much Appreciated.

 

Compression test tells the whole story.
If you're very lucky, it's just the head gaskets blown out with warped heads.

More than likely, cracked the cast iron heads. These are thin cast and take no overheats.

shop repair more than the van is worth.

 

Wouldn't there have to be water in the oil for this to happen? My dipstick was clean.

 

If the block is cracked, maybe water will get into the oil. But this does sound like a head gasket or warped head problem, where combustion gases would push into the coolant. You can confirm this by smelling the coolant for gas fumes.

I know the van is at the mechanic's now, but did you check all the plugs to see if any were wet? I guess you didn't perform a compression test, so you have to see what your mechanic found.

 

You will only get oil in the coolant if a passage between and oil gallery and the coolant jacket forms. This happens a fair amount of the time, but is by no means a guarantee.

 

It's hard to believe the head could crack so fast, I only saw a small amount of steam in the hood, when the engine started stalling; there was no white smoke from the tailpipe I remember. But there is a burnt-electrical like smell from the heater hose.

shop repair more than the van is worth.[/QUOTE]

Since it is a wonderful work-van, it will be resuscitated. It is not worth repairing the head due to the unknowns and the labor, and also since a complete engine swap with a guaranteed low-mileage is about $1300 (from a reputable engine co).

Being "on suspicious-mode" around mechanics, I wish I would have done a compression test on at least the 3 plugs on the drivers bank (easier), so I could go into this assured. The only plug I saw was the #1 and it was black from carbon in trying to start it without firing on.

 

This statement seems to go along with the fact that you've lost compression somewhere. Feeling air coming from the cylinder is not the same as measuring the correct amount of pressure. Turning an engine over without spark plugs (no compression) sounds a whole lot different than turning over an engine for a normal start. You've probably lost compression on a good number of the cylinders.

 

The steam you saw was probably from the heater hose bursting. If you did not notice that happening, the engine would have been run low on coolant, so it overheated, which could cause the heads to warp. You can ask your mechanic to replace the heater hose, and do a pressure test of the cooling system. That will tell you if the heads are warped, or the head gasket is blown.

It's also possible that when the heater hose blew, some of the coolant could have gotten into some electrical components, causing starting problems.

 

I like the pressure test suggestion which is quick and will answer my nagging concerns. The steam went right over the TFI, which I swapped, but the stars were not in my favor and no-go,

 

While cracked/warped heads and blown gaskets are highly likely, from my experience, I would certainly do a lot of checking before trashing a serviceable vehicle.

I just finished (several weeks ago) a 92 4.0 and can tell you that not everytime they overheat a little it blows gaskets or cracks parts.

A reputable ford dealership told my 95 year old mother in law (daughter drives for her) that a gasket had blown and the motor would cost more to fix that it was worth. This was after a supposed radiator test for gases. They also had a lot full of vehicles to sell . It was not leaking water on floor overnite, coloring the tailpipe, or going into the oil pan, so I suspected something. It could even be driven some, but once it got in stop and go, and the temp rose a little, it would not stop going up until you stopped and cooled. Since the oem thermostat was not opening at all (discovered later) The only place I could see to circulate water was the small bleed hole at the thermostat edge. I dont see how, but that had to be it! I now even check new T-stats on the stove w/pan of water before installing. Especially as difficult to get to as these things are. Granny was afraid to trust the thing even if it could be fixed. So I wound up with it.

I replaced the water pump (was in great shape at 66K miles), replaced the thermostat (water pan test showed it was not opening at all) with a 180 deg (yea, I know ~192 deg oem) it runs at ~190 in the fl heat. Will get to about 220 with much idleing, but comes down quickly when rolling. Replaced the heater hoses and built brass "T" valves for rear heat and waterpump bypass. Replaced plugs and wires and belt. It runs great for several thousand miles now. Daughter hauls grands around for school, doctors etc.

I am not saying that yours could not be something bad, but just do your own checking. So many people do not read the entire posts and mis-quote the posts. It happens here! Sorry for the long post, but this overheat issue with aerostars needs careful diagnosis

 

Thanks for the optimistic input, but at this point, the engine was replaced with good running used one. I went to three different mechanics and when they heard the "overheat story" for a Ford Aero, they diagnosed a cracked head; most didn't even want to run any tests.
Anyway, we are up and running and thanks to all for the good advice.

 

Glad to hear you are up and running
I had read a lot about the difficulties of replacing a bad engine, thank goodness I didnt have to do that-----at least not yet Now all I have to do is dig into replacing the upper arm bushings, rubber is pretty well rotted/dried out. First thing "next" Monday or the next after that----

 

You can pull the A-frames out (not too difficult) there are 2 long vertical bolts running through the springs, and 2 horizontal through A. Take them to a machine shop for the press.

 

You can pull the A-frames out, not too difficult, there are 2 long vertical bolts running through the springs, and 2 horizontal through A. Keep the alignment shims in order. Take them to a machine shop for the press.

 

Yea, I have seen the articles on doing that. Soon as the skin grows back on my arms from doing the work I did and I can get motivated, I need to do the bushings.
After a certain age, motivation to work on stuff leaves us especially if it is not daily transportation.