If your Ford 3.0L, 3.8L Taurus (or Aerostar, Mustang, Windstar, Sable, Cougar, etc.) is overheating, and you have already verified that the thermostat, the fan motor (or fan clutch), the water pump are not the problem, you may have a blown head gasket on your hands. This article will help you to get to the bottom of the issue with three easy blown head gasket tests.
All three head gaskets tests are explained in a step-by-step way and more importantly, they include and interpretation of your test results (after all, what good is a test if you don't have the info to interpret what you just did and the results you got?).
Two of the blown head gasket tests I'm gonna' describe here, are done with no tools at all. The third head gasket test is done with an engine compression tester.
Contents of this tutorial:
TEST 1: Oil The Color Of ‘Coffee With Too Much Cream’
The first to two tests are the easiest and will take you less than 5 minutes to do. In about 90% of the time, these two first head gasket tests will positively confirm a blown head gasket on your 3.0L, 3.8L Ford Ranger (or Topaz, Probe, Tempo, or Mazda B3000, etc.).
If this first head gasket test confirms that the head gasket is burned, you don't need to do the other tests. OK, I'll stop yakking and we'll get this show on the road, this is what you need to do:
Open the hood on your 3.0L, 3.8L Ford car (or mini-van, pick up) and once open, pull out the engine's oil dipstick.
Now, check the oil. What color is it? How thick is it? What you're doing is confirming one of two things:
1.) Either the engine oil will be a creamy tan/off white color and as thick as syrup Or...
2.) The engine oil is a normal color and viscosity.
Now, let's find out what each of the two results mean:
CASE 1: The color of the oil is a tan/off white color., this is not good and proves beyond a shadow of a doubt that the head gasket is blown on your 3.0L, 3.8L Ford, Mercury or Lincoln vehicle.
Why does the oil look like this? Mainly because your 3.0L, 3.8L Ford car (or mini-van, pick up) over-heated and :
1.) The overheating caused the cylinder head (or heads) warp. This in turn causes the head gasket (or gaskets) to burn.
2.) Now since the head gasket's job is to keep everything separated and sealed (engine oil, coolant, compression and exhaust gases, etc), when it gets blown... stuff starts to mix...
3.) ...and so when coolant mixes with engine oil, as the engine runs or cranks, the resulting mix turns into an off white/tan color.
CASE 2: The color of the engine oil is normal, So far so good, but you're not out of the woods yet. You'll need to do the other two tests to further confirm a BAD head gasket or exonerate the head gasket. Go to HEAD GASKET TEST 2.
Here's why: Any automotive mechanic or technician will confirm that one of the most common results of a blown head gasket is oil mixing with the coolant. This usually happens in about 90% of the cases of a blown head gasket... the other 10% of the time, you're not going to see this happening. And so, further testing is required to make sure that the head gasket is really blown or not. The next test is to see if the engine's compression/ combustion gases are escaping thru' the radiator.