How to test for a bad head gasket

Here is another head gasket test video where I am using a chemical kit and comapring it to the gas analyzer for accuracy.

Engine Performance Diagnostics chapter 1 page 13

Symptoms
- misfire with a cold engine
- white smoke from tailpipe
- loss of coolant
- long crank time
- overheat

Fix
- replace faulty head gasket

Tests shown
- how to use a gas analyzer to test for a blown head gasket
- why checking for milkiness in the oil is not a fool proof test

Tools used
- 5-gas analyzer
- combustion leak detector

Playlist
- (Chapter 1) Misfire ID, Compression Tests, Vacuum Leaks, Fuel Trim, Head Gasket, Restricted Exhaust, Low Power, DMM

Related videos
- How to test for a bad head gasket (chemical test)

This is a review of a test procedure I have in my ebook. Section 1 "Universal Testing Methods" page 13. There are other ways to do this test. I am just showing the one I use the most when looking for a bad head gasket.

On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!

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Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.

[ScannerDanner]

Hey guys, you can buy a kit for around $50 that will do the job of this gas analyzer that I am using in this video. Here is the link
and here is a video of me using it

[reyzapata]

Hi, I’m Rey Z. I had the same thing done to my 70 Impala last month I have a 350 engine. and the reading for the HC was 15. The smog guy and the mechanic said I had a blown head gasket. But when I took off the intake my intake gasket was blown.. because I had no water in my oil. on the valves. And no bubbles in my new radiator. Gasses was leaking throw my intake. I cleaned up the intake and replaced the old gasket with a new Fel-Pro gasket. Now my car doesn’t over heat and it runs beautifully.😇🙏🏽👍

[ScannerDanner]

Good tip Jeff. I believe another one to watch out for is the GM 3800 engine. Not sure about the HCs in the coolant but all the other symptoms of a head gasket will be there

[ScannerDanner]

No problem man, all of those tests are good. I just found this one to be the quickest and most accurate. Although I've never used the "blue fluid kit".
You know as well as I that all of the other tests you mentioned are NOT 100%. This one is. I have had many cars pass all of the conventional head gasket tests over the years with an early head gasket failure.

[steveguest]

I must say some of the derogatory comments on here towards Paul are completely out of order, I've been in the motor industry for over 30 years and have learned a lot from his videos, please show the guy the respect he deserves.

[racingdreamz]

I used a bottle of Steel Seal to fix my head gasket, drained the coolant, removed the thermostat, flushed the cooling system really good, Then use a radiator cleaner to clean the cooling system, Make sure to flush out all the cleaner 100%, When engine is 100% cold add steel seal with distilled water, turn heater on high & let idle for 30 mins with the radiator cap it cool for 1 hour the let idle again for 30 mins with the radiator cap morning let it idle for another 30 mins then removed all water from the system to let the steel seal cure for 24 hours, Replace the thermostat, fill with coolant and your good to go. Mine has been running perfect for 70k miles now as i use the car for uber & lyft, Only cost me about $120 total.

[kevinkinney]

This is the second video of yours I watched, neither pertained to a problem I had in common, they just appealed to my intellectual principle by intrigue and interest.
...You, My friend, are now My favorite YouTube Mechanic. Hopefully, I'll have a problem that You have covered. Until then, the educational value is very high. Thanks for knowing WTF you're talking about. Good job!

[ScannerDanner]

Yes, you can buy a test kit, kind of like a litmus test where your looking for the color of a test strip to change a certain color. I never used one but I know they are out there. In fact I think there are some videos on it on youtube.

[ScannerDanner]

"As a mechanic you should identify and eliminate problems first"
what do you think I did? and it took me 5 minute to do it.
there was no tailpipe white smoke, no milkiness in the oil and compression would have tested good too. (typical early stages of headgasket failure)
why would you not want to do this easy test first? not sure what you are fighting me on here. simple test to do, present the customer with his options right away. No need to be a parts changer to figure out the problem

[MIdru]

You are a true master of your craft ScannerDanner. I find all of your videos extremely informative and educational. Even though I will never be able to afford a full feature scanner like a Modis, I can still take something away from your videos. I really wish I could work with someone as knowledgeable as you, instead of all these pre-maddonas and hack-jobs, its very disillusioning and frustrating. Im saving up to buy your book, and thanks again for all you've done for the learning community.

[ScannerDanner]

if I was doing the repair I would most likely follow up this test with a leak down test. this way I would know exactly what cylinder and would be able to focus better in that area once the cylinder head was removed. also if I'm pulling 1 cylinder head off they're both coming off.

[modfydgarage]

long crank startup and leaking oil (wet spots) near the head gasket area = confirmed blown head gasket in my case. I also experience loss of power and bad gas mileage. I love these videos. So much information!

[ScannerDanner]

just based on the symptoms I decided to do that test first as it was very quick and very easy to do

[simonjohnhinton]

i have a mk2 mondeo 1.8 zetec-e which had a top end de coke, valve stem oil seals and piston oil rings because it struggled through the emissions test. i also had in the past a 2.0 zetec-e which had a small combustion leak with an occasional mis fire and I remember having to top up the coolant once and a while. head gasket failures were more common on the 2.0 zetec engines than than1.8 and use to fail on no.3 cylinder.

[stressedout]

Also people when he says check the Oil cap sometimes there is a little milkiness in some of those Doesn't mean the head gasket is blown up Humidity does get in

[Jerkwaad]

CORRECTION TO THE VIDEO: The fact that there's milky color on the cap/dipstick does not determine whether you have a bad HG or not, and here's why: For every burnt unit of gasoline, the largest byproduct is water. Now some of that water gets by the piston rings and enters the crank case. This escaping of burnt gas is referred to as Blow-by. Now disregarding unburnt fuel and Nitrous Oxides, this gas is mainly CO2 and water. Mostly water even. And since it has just been burnt, it is still warm. Thus is a fair quantity of water vapor present in the crank case, and water vapor likes to condensate on the closest cold area. In many cases (depending upon engine design) the oil cap and the top of the dipstick are the coolest part of a warmed-up engine. And that's how and why you get the condensation on the dipstick/oil cap. 

[nickrtvt]

love your videos man, I'm a second year apprentice and have learned a lot from you.

[Goultek]

haters gonna hate, but I'm a pro and everytime I watch one of those videos I learn something

[crystrezerexlife]

I had a vehicle that was passing the engine block test Everytime, no overheating, The overflow bottle was losing coolant on a consistent basis, I had to keep adding coolant. Turns out the headgasket was only bad on the coolant port at cylinder #1, so Raw fuel, plus coolant was just exiting the exhaust pipe and causing the pipe to glow red.

[EdwinHenryBlachford]

more and more modern engines have direct firing fuel injectors, where the injector nose is in the combustion chamber & is cooled by coolant fluid passing through the head. If the injector seals leak, combustion gases can enter the coolant. With such engines, many times a head is changed mistakenly since the symptoms are exactly the same as a cracked head. Always read the workshop manual thoroughly. most injector/combustion chamber seals are of copper and as cheap as $4 each