mike200

About 7 years ago, the fan switch went bad and my wife ran the engine very hot. She took it to her uncle's shop and he said that a head gasket was blown. He said that he fixed it but it continued to run slightly hotter than normal. A few months ago, I had to change the radiator because it was cracked bellow the filler neck. It ran fine for about a week before it ran hot again. The temp. gauge would flucuate from cold to hot and the heater would blow cool and hot air in 96 degree weather! Now when I start the car in the morning, it misses until it warms up. There is no oil in the water, but I think the head gasket is blown. Maybe that one cylinder is filled up with water causing it to miss. Also I removed the thermostat to see what happens and no improvement. I have backflushed the heater core thinking it may have blocked, but it flow freely. Today I went to check the water in the radiator after 5 hours from driving it and there was pressure behind the cap. It shot out some water that was cool. Where did the pressure come from? Defective cap? Need help bad.

FEAnt

3.8liter engines have a history of head gasket issues in Mustangs. Get it to a mechanic, I have a feeling the issues at hand are pretty significant.

mike200

I thought so. What about the water pump? I hate to say it, but I have run straight water in it for a while. The reason was because it was loosing so much water and did not intend on driving so much until it was fixed. A friend told me he had the same thing in a truck and the impeller rusted off. When I change the head gaskets, I will pull the water pump and check it out. I will also take the the haeds off and have them shaved. I want to squeeze everything I can from that little v6. Thanks for the help.

FEAnt

Although its not a given, water pumps can last upwards of 120K miles. Running straight water is not a good idea. In addition to a different temperature range, antifreeze also offers anti-corrosion properties that is not in straight H2O. Don't forget to fill with a 50/50 antifreeze & water solution.

mike200

Thanks again. The Mustang has 122,000+ miles on it. I will change it when I do the heads.

sammy51

I know the answer! Mike200 I bought a 95 Mustang that did the same thing and I figured out what the problem was. A Ford dealer mechanic should have no problems figuring this one out. In the return heater hose, there is a reducer valve that went defective. It blocks the ammount of liquid that goes to the fan sensor. remove the valve and blow in the hose. This will solve the problem of overheating. Let me know if you need to put a reducer valve there, because I have'nt yet. If I'm not clear, let me know, I'll explain better. If the water pump don't make noise or leak, its not broken!

sammy51