How To Test For A Blown Head Gasket (1991-1996 1.9L Ford Escort, Mercury Tracer)

Checking for a blown head gasket isn't complicated. In fact, you've got four different tests you can do to find out if the head gasket on your 1991-1996 1.9L Ford Escort or Mercury Tracer has failed.

In this tutorial, I walk you through all four. Two of them don't need any tools and only take a few minutes to do.

The other two involve a little more —one is a compression test with a compression tester, and the other is a block test with a combustion leak detector.

Hopefully you're not dealing with a blown head gasket. But if you are, one of these four tests will confirm it for you.

APPLIES TO: This tutorial applies to the following vehicles:

• 1.9L Ford Escort: 1991, 1992, 1993, 1994, 1995, 1996.
• 1.9L Mercury Tracer: 1991, 1992, 1993, 1994, 1995, 1996.

Symptoms Of A Blown Head Gasket

This isn't every single symptom a blown head gasket can throw at you, but these are the most common ones you're likely to run into when you diagnose one of these engines:

1. You start the engine and it overheats within minutes for no clear reason, even when the cooling system looks like it's working right.
2. You find engine oil mixed with coolant, causing it to turn into a milky-white color.
3. You see white smoking come out of the tailpipe (which is antifreeze burning inside the cylinders).
4. The engine cranks but refuses to start.
5. You've got no compression on two side-by-side cylinders.

TEST 1: Engine Oil Mixed With Coolant

The head gasket on your 1.9L Ford Escort or Mercury Tracer keeps three critical engine elements from crossing paths: the coolant, the engine oil, and the combustion pressures/gases inside the cylinders.

To break it down, the head gasket's job is to:

• Keep the coolant contained and flowing only through its passages in the block and cylinder head.
• Keep the engine oil in its own galleries and out of the cylinders where it doesn't belong.
• Keep the combustion pressure sealed tight inside each cylinder so you don't lose power.

When the engine overheats badly, the aluminum cylinder head warps or the gasket itself burns through, and that's when those three elements begin mixing together.

From what I've seen over the years, the most common result of a blown head gasket on a four-cylinder engine is the coolant mixing with the engine oil. When that happens, the oil turns a milky-white color, like coffee with too much creamer.

For our first head gasket diagnostic test, we'll check the color of the engine oil sticking to the engine oil dipstick.

These are the test steps:

1. 1

   Open the hood.

2. 2

   Pull out the engine oil dipstick.

3. 3

   Check the color of the oil sticking to the dipstick.

4. 4

   You'll see one of two things:
   
   1.) The color of the oil will be a milky white color (like coffee with too much creamer).
   
   2.) The color of the oil will be its normal color.

Now, let's see what your test result means:

CASE 1: The engine oil is a milky-white color (like coffee with too much creamer). This is a clear sign the head gasket on your 1.9L Ford Escort or Mercury Tracer has failed and that coolant is mixing with the engine oil in the crankcase.

CASE 2: You see the engine oil hold its normal old or dirty color. That's a good sign so far, but it doesn't mean you can rule out a blown head gasket just yet.

Your next head gasket test is: TEST 2: Coolant Shooting Out Of Radiator.

TEST 2: Coolant Shooting Out Of Radiator

So far, TEST 1 confirmed your Escort or Tracer's engine oil isn't mixing with coolant —since it hasn't turned a milky-white color.

Now, we'll check if the head gasket is still sealing the compression, combustion, and exhaust gases inside the cylinders the way it should.

We can do this easily by taking the cap off the radiator and seeing if coolant gets shot out of the radiator while cranking the engine.

If coolant does get shot out of the radiator neck (while cranking the engine), your Escort or Mercury's head gasket is blown.

IMPORTANT: Never do this test on a hot engine! Coolant under pressure can spray out and cause severe burns. Always make sure the engine is completely cold before you remove the radiator cap.

This is what you need to do:

1. 1

   Remove the radiator cap from the radiator.
   
   IMPORTANT: The engine should be completely cold before you open the radiator cap.

2. 2

   Check the coolant level.
   
   If the coolant level is low, top it off with water before going on to the next step.

3. 3

   Stand at a safe distance (from the engine) but within eye-view of the radiator.

4. 4

   Have your helper crank the engine.

5. 5

   You'll see one of two results:
   
   1.) The coolant shoots out when the engine was cranked.
   
   2.) The coolant was not disturbed at all.

Let's examine your test result:

CASE 1: The coolant shot out of the open radiator. This confirms the head gasket on your 1.9L Ford Escort or Mercury Tracer is blown.

CASE 2: The coolant stayed put (undisturbed) in the radiator. That's the test result you want to see, and so far things look good.

From here, what you do next depends on how the engine behaves:

• If the engine doesn't start, go to: TEST 3: Engine Compression Test.
• If the engine starts but runs hot, head over to: TEST 4: Using A Chemical Block Tester (Combustion Leak Tester).

TEST 3: Engine Compression Test

Over the years, I've run into more than a few vehicles with a blown head gasket that didn't show the usual signs. The engine oil wasn't mixed with coolant, and cranking the engine with the radiator cap off didn't send coolant shooting out either.

Even without those symptoms, the head gasket had blown and kept the engine from starting, and it was the compression test that ended up nailing what was really happening.

What happened in those cases was the gasket burned through between two side-by-side cylinders, causing them to lose their ability to compress the air/fuel mixture.

If you take a look at the photo of the head gasket at the beginning of this tutorial, it shows you exactly that kind of failure.

To check if the same thing has happened on your Ford Escort (or Mercury Tracer), we'll do an engine compression test in this test section.

NOTE: This tutorial explains how to do and interpret the compression test in more detail: How To Test Engine Compression (1991-1995 1.9L Ford Escort, Mercury Tracer).

Here's what you need to do:

1. 1

   Disable the fuel system by removing the fuel pump relay.

2. 2

   Disable the ignition system by disconnecting the ignition coil pack from its connector.

3. 3

   Disconnect the spark plug wires from the spark plugs. I strong recommend you use a spark plug wire puller for this (to avoid having the wire's metal terminal stay stuck on the spark plug).
   
   NOTE: Label the spark plug wires so that you can reconnect them back to the correct spark plug when you're done.

4. 4

   Remove the spark plugs.

5. 5

   Install the compression tester (hand tight only) on the first cylinder you're gonna test.

6. 6

   Have a helper crank the engine while you observe the compression tester.

7. 7

   Have your helper stop cranking the engine once the needle on the gauge stops climbing.

8. 8

   Write down the compression readings.

9. 9

   Repeat steps 5 through 8 on the remaining cylinders.

Let's take a look at your test results mean:

CASE 1: Two side-by-side cylinders show 0 PSI compression. The head gasket has failed and is letting those two cylinders' compression bleed into each other.

CASE 2: All cylinders hold good, solid compression. This is the correct and expected test result.

If you're troubleshooting an engine no-start problem, this result rules out the head gasket as the cause of the issue.

TEST 4: Using A Chemical Block Tester (Combustion Leak Tester)

I've run into cases where the vehicle had a head gasket issue, but its engine still started and ran, and didn't show any of the symptoms that the first three tests are designed to confirm.

In these particular cases, what happened instead was that the engine overheated within minutes of starting, and for no obvious reason.

When you run into this type of situation, the surest way to confirm or rule out a head gasket failure is to do a block test with a combustion leak detector.

Because of how effective it is, the block test is the standard test repair shops turn to when they have to confirm a blown head gasket with absolute certainty.

Here's how it works:

• You start by filling the tester with a special blue chemical (see photo above).
• Next, you place the tester assembly on the open radiator neck.
  • You may need to drain a little coolant first, since the tool needs to gulp some of the air sitting inside the radiator.
• With the tester in place, you start the engine.
• Now you squeeze the rubber bellow to pull the radiator's air up through the two fluid-filled chambers.
  • As the air bubbles up through the fluid, it causes a chemical reaction.
• If the blue chemical turns yellow (on a gasoline engine), that tells you combustion gases are entering the radiator. This confirms you're dealing with a blown head gasket, a cracked block, or a cracked cylinder head.
• If the blue chemical stays blue, then you can conclude you're not dealing with a blown head gasket, a cracked block, or a cracked cylinder head problem.

Where can you get the chemical and block tester? Here:

Frequently Asked Questions

1.) How can I tell if the cylinder head is cracked?

The only accurate way to do this is with the cylinder head removed from the engine block. At that point, you can either perform a visual inspection yourself or have the head pressure-tested.

If the crack is large, you'll usually spot it right away without special tools. But if nothing obvious shows up, a machine shop can pressure test the head to confirm or rule out a hidden crack.

2.) How can I verify if the cylinder head is warped?

Checking for warpage can only be done with the cylinder head removed from the block. Once it's off, the first step is to clean the head gasket surface completely.

Next, you need to place a precision straight-edge across the gasket surface and use feeler gauges to check for gaps. Any spot where the gauge slips under the straight-edge confirms the head isn't perfectly flat.

This method is the only accurate way to determine if the cylinder head is warped.

And if the engine overheated (which is usually what causes a blown head gasket), you can assume the head is warped. At that point, machining or resurfacing it at a machine shop isn't optional —it's required.

3.) Do I need to resurface the cylinder head?

Yes. Any time the head gasket has failed, the cylinder head should be sent to a machined shop to be checked (with a pressure test) and then resurfaced to make sure it seals properly when reinstalled.

Skipping this step risks another head gasket failure, especially if the engine has overheated.

More 1.9L Ford Escort And Mercury Tracer Diagnostic Tutorials

You can find a complete list of 1.9L Ford Escort and Mercury Tracer tutorials in this index:

• 1.9L Ford Escort Index Of Articles.

Here's a small sample of the tutorials you'll find in the index:

• How To Test The MAF Sensor (1991-1995 1.9L Ford Escort, Mercury Tracer).
• How To Test The Fuel Pump (1991-1996 1.9L Ford Escort, Mercury Tracer).
• Common Causes Of Spark Plug Failure (1991-1995 1.9L Ford Escort, Mercury Tracer).
• How To Test Engine Compression (1991-1995 1.9L Ford Escort, Mercury Tracer).