Checking to see if your 1.7L Honda Civic has suffered a blown head gasket can be done in 4 simple tests.
In this tutorial, I'll walk you through all 4 in a step-by-step way so that you can do these tests yourself (if you suspect your 1.7L Honda Civic has a blown head gasket).
Contents of this tutorial:
Symptoms Of A Blown Head Gasket
If your Honda still starts and runs... the most common symptoms of a blown head gasket is that the engine overheats rapidly.
Here are a few other common symptoms a blown head gasket:
- Your Honda Civic is overheating. You've checked that:
- Thermostat is good.
- Both the radiator fan and condenser fan are working.
- Radiator is not busted (leaking coolant).
- Water pump is OK (not leaking coolant).
- Cooling system is full of coolant.
- White smoke is coming out of the tail-pipe and it smells like anti-freeze being cooked.
- Your Honda won't start. You've checked:
- There's spark coming from all 4 ignition coils.
- Fuel is reaching and being injected into the cylinders.
- The engine oil is thick and a tan to an off-white color.
TEST 1: Engine Oil The Color Of ‘Coffee With Too Much Cream’
The most common end result of a blown head gasket is coolant leaking into the crank case where it mixes with the engine oil.
As your Honda Civic's engine is cranked (or as it runs), the oil thoroughly mixes with the coolant and becomes milky white in color.
This can be confirmed by simply pulling out the dipstick and checking the color of the oil and that's what we'll do in this first test.
OK, I'll stop talking and we'll get this show on the road, this is what you need to do:
Open your Honda's hood and pull out the engine oil dipstick.
What you're looking for is to make sure that the engine oil IS NOT mixed with coolant. If the engine oil is mixed with coolant, it'll be the color of ‘coffee with too much cream’.
What color is the engine oil?
1.) Is it a creamy tan/ off-white color or...
2.) The engine oil will be its usual normal color.
Alright, let's interpret the color of the engine oil:
CASE 1: The color of the oil is a light tan, like coffee with too much cream, and your Honda starts and overheats or does not start.. then this result confirms that you Honda's head gasket is blown.
If you're wondering why the oil looks like this? Well this is what happened:
1.) Your Honda overheated to the point that the cylinder head warped (since it's made out of aluminum). This led to the head gasket to burn.
2.) Once the head gasket burns and the head warps, the head gasket is unable to keep engine oil, coolant, and compression/ exhaust gases from mixing.
3.) This leads to the coolant entering the engine oil pan.. As both of these mix... the result is an engine oil that is an off-white/tan color.
CASE 2: The color of the engine oil is normal, so far so good, but more testing is necessary to make sure the head gasket is not blown (especially if your Honda is overheating or not starting), go to TEST 2: Coolant Shooting Out From Open Radiator.
Here's the reason why: In about 90% of the times, a blown head gasket will cause the engine's coolant to mix with the oil, but not always. And so another test or tests are needed to either confirm a blown head gasket or exonerate the head gasket as blown. The next test is to see if the engine's compression/ combustion gases are escaping thru' the radiator.