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diagnosing a blown head gasket

Greggles_VS

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How are ways to tell if my headd gasket is blown? So far my only real tell tale sign is overheating. Cooling system seems ok but can get warm fast, could my thermostat get stuck and cause a problem? Could my heater core affect it? What would I look for in my liquids that could be a sign? Cheers
 

K-BAGZ

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Perform a cooling system pressure test and a dry and wet compression test. Minimum Ecotec V6 compression is 100psi.

Bubbles in the filler neck of the radiator can indicate a blown head gasket. White smoke out of the exhaust also. Dropping coolant level too. Coolant in oil, or oil in coolant as well. Check the condition of the oil on the dipstick, the oil would appear milky and cloudy. Also the condition of the coolant in the radiator filler neck, the coolant would have small deposits of oil floating around.

Compression Test Procedure.
1. Make sure you have a fully charged battery.

2. Run the engine until operating temperature is reached.

3. Turn the engine off and disconnect the spark plugs leads for the coil packs and spark plugs.

4. Remove the engine and fuel pump fuses.

5. Remove a spark plug and install the compression tester into whichever cylinder you want to start in. 1-6, 6-1, 1-3-5, 2-4-6. Whatever way you want.

6. You need another person to fully depress the throttle pedal and crank the engine over. Only crank the engine a maximum of four compression strokes (thumps) at a time, while observing the compression tester gauge and note down the highest reading.

7. Test the following other cylinders and compare all the readings at the end. The lowest reading on any given cylinder shouldn't be lower than 70% of the highest reading cylinder.

If a low compression reading is noted on one or more cylinders, you can 'wet test' the engine to isolate the issue even further. Add a small amount of engine oil in the combustion chamber of each cylinder and repeat the compression test again.

An large increase reading of compression pressure indicates that the piston rings, piston and/or cylinder bore are worn. A low increase reading of compression pressure can indicate burnt, obstructed or sticking valves or a leaking cylinder head gasket.
 
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RX25SE

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Check the temp gauge is operating correctly.

Not uncommon for it to show that it is overheating when in fact all is good.

A scan tool will show actual temp from the ECUs sensor rather than the sender for the gauge.


TBH blown headgaskets on ecotec's are not all that common, whereas a failed inlet gasket happens to all of them.
Causes very similar symptoms to a blown head gasket.
 

Immortality

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A good condition ecotec should get about 170-180psi when doing a compression test. If it's down to 100 psi on a hot compression test it's time for a new engine.
 

RX25SE

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Remember that the OP's complaint was overheating.
 

Greggles_VS

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I checked all my levels and put in some new spark plugs. Was a small amount of Brown build up on my new radiator cap. Coolant level dropped about .5l and my oil has dropped about half on the dipstick.
 

pendles

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buy a head gasket tester. it's a hand held pump thingo that you stick on top of your radiator with cap off.
car running when it's hot and pump it, it has blue liquid in the pumps container that will pick up co2 and if it has a cracked head gasket the blue liquid will detect co2 and the chemical reaction will change the colour to yellow.
 

K-BAGZ

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buy a head gasket tester. it's a hand held pump thingo that you stick on top of your radiator with cap off.
car running when it's hot and pump it, it has blue liquid in the pumps container that will pick up co2 and if it has a cracked head gasket the blue liquid will detect co2 and the chemical reaction will change the colour to yellow.

Combustion gas leakage tester. Very, very handy tool.
 

pendles

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thats the name hah, dont know what it's called I just use the bad boy at work. it is indeed a very handy tool imo.
 

Greggles_VS

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Would this be what your talking about?
http://pages.ebay.com/link/?nav=item.view&id=190734276084
 
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