how to tell if Head Gasket is blown?

[Hognosh]

Just wondering how to tell if your head gasket is blown. Ive been having issues getting tractor over 2200 rpm. and i have another post on this talking to others now im wondering if it is head gasket issues or just air issues. what do i look for to rule out head gasket.
thanks

http://www.tractorbynet.com/forums/parts-repairs/305474-cant-get-over-22-000rpm.html

 

[pmsmechanic]

Run the engine with the rad cap off. If you see bubbles in the antifreeze that would be a good indication of a blown head gasket. Check your oil and make sure it's not a greyish color. You can also stretch a balloon over the radiator neck and see if it fills up.

 

[2458n]

You could also do a pressure test on your radiator. pump it up and set the pressure and see if it bleeds off. Are you using antifreeze without it leaking. Can you smell antifreeze at the tail pipe? All are good clues.

 

[tractorboy3011]

I had this ploblem too look for water in oil.

 

[GManBart]

White smoke in the exhaust, and coolant in the oil are two primary indicators.

 

[LD1]

Three ways a head gasket can fail.

1. Cylinder to water jacket.
2. Cylinder to oil passage/pushrod passage
3. Cylinder to air
4. Cylinder to cylinder

No way to pin things down 100% without popping the head. But advise given so far is a good start.

Looking for bubbles in the coolant is a pretty good bet that the gasket is blown into a water jacket. But not seeing bubbles dont rule out the gasket.

Water in oil is also a good indication of being blown, (or cracked block). But clean oil dont rule out the gasket either.

If it were leaking to air, a simple walk around feeling and listening around the head should tell you.

After those quick visual checks, you need to do a compression test. Cause even if all of the visuals pass, it could still be blown cylinder to cylinder.

And even the compression test isnt foolproof. You may show a low cylinder or two, and think that you have a head gasket problem, so pull things appart and it could be something like a busted piston or ring in that cylinder.

So I guess to sum up what I am saying, there is nothing you can do to 100% verify if it is a head gasket short of pulling the head. But there are alot of steps that can help point you in the right direction.

Now if she passes all the tests above including the compression test, I'd be looking elsewhere for the issues you are having. Valve adjustment?

 

[john_bud]

Head gaskets keep the combustion gasses in the cylinder and separate from the liquid coolant. A leaking head gasket can leak ;

1) cylinder to cylinder
2) cylinder to coolant
3) cylinder to environment

symptoms can be hard to start if pressure is bled off to adjacent cylinders. Can be coolant out the exhaust or exhaust bubbles in the coolant that you can see in the radiator. Can also be a pulsing sound as cylinder pressure is leaked out between the head and block to the environment.

Pretty easy to determine a bad leak by inspection of the exhaust / radiator flow. A leak down test will tell you more and let you determine which cylinder is leaking and where it is leaking to.

My suspicions are more toward fuel system than head gasket, but from this distance .... its only a guess.

 

[rsallen]

I've run into head gaskets burn between cyl.'s as well or into an oil gallery.
They don't always burn into the coolant system.

 

[rsallen]

The most reliable way to test for head gasket leakage is to pressurize each cyl. in turn.
While it's not possible to pressurize the cyl's to ignition pressures it is the most reliable way to test head gasket integrity as well as a number of other suspect causes of problems.
Pressurize the cyl's and check for where the air pressure escapes. Simple concept and it works.

But from the op it sounds to me like he's looking in the wrong place for his problems.

 

[LD1]

The most reliable way to test for head gasket leakage is to pressurize each cyl. in turn.
While it's not possible to pressurize the cyl's to ignition pressures it is the most reliable way to test head gasket integrity as well as a number of other suspect causes of problems.
Pressurize the cyl's and check for where the air pressure escapes. Simple concept and it works.

But from the op it sounds to me like he's looking in the wrong place for his problems.

But even that is still no gaurentee. IF you pressurize a cylinder and get bubbles in the coolant, it "could" be a head gasket. Or it could be a cracked block, or cracked head.

There is NO way to be 100% sure until you pull the head.

I would do some of the checks that people have advised. if any of them checks fail, pull the head and see. But if they all pass, it "could" still be a headgasket, but that would be my last resort to look into. There are far simpler things to check and rule out that could be causing your issues.

 

[rsallen]

Yep, pressurizing only tells you yes, you're in going in the right direction or not. It does not definitively definite the problem.
And yes you're right there are real and multifaceted reasons that may lead one in that direction.

And given the limited information from the op'er I still maintain that the op is 'probably' looking in the wrong place.

 

[Baby Grand]

I've run into head gaskets burn between cyl.'s as well or into an oil gallery.
They don't always burn into the coolant system.

Me too - had a gas burner sucking engine oil into the combustion chamber where the gasket was gone. Real smoker, that one.

 

[skyhook]

Napa auto parts sells a test kit for this, just put it over your rad cap section
and run the machine. It will tell you if you have a combustion leak somewhere.

 

[LD1]

For $35 I think I'd pass on that kit.

And again, it will only tell you if you have a leak into a coolant passage. But it dont tell you it is a head gasket for sure.

And just because it passes that test, dont mean the head gasket is good either. It could be blown to another cylinder, blown to atmosphere, or blown into an oil passage and that kit would leave you feeling like everything is good.

 

[skyhook]

For $35 I think I'd pass on that kit.

And again, it will only tell you if you have a leak into a coolant passage. But it dont tell you it is a head gasket for sure.

And just because it passes that test, dont mean the head gasket is good either. It could be blown to another cylinder, blown to atmosphere, or blown into an oil passage and that kit would leave you feeling like everything is good.

I disagree,,

And just because it passes that test, dont mean the head gasket is good either. It could be blown to another cylinder,
It will detect that, if it blows to anther cylinder, it still has to come out somewhere.

blown to atmosphere, You would "see" this, no need for the kit then.
or blown into an oil passage and that kit would leave you feeling like everything is good.
Nope, you would also see this in the oil.
I mean, you do all your usual test first, visual, etc,,
Look at the oil for water,
look at the rad interior for oil.
Look around the head for leaks,,
but this tester will "sniff" for gases you can't see and should not be there.

 

[rsallen]

There have to be real reasons to even suspect a head gasket to begin with.

We have been given no as in zero info from the op to indicate a head gasket problem of any sort.
If we start going through all the different symptoms and scenarios that head gaskets go or all the ways we've seen them blown all we'll do is completely confuse the man and send him to places he may not need go.

Let's start with how the tractor is acting, the model, the year and hours.

 

[skyhook]

He did say he would like to rule out a "head gasket' issue in his first post.
This is the info members have given him.
But I do agree with your post.

 

[LD1]

I disagree,,

And just because it passes that test, dont mean the head gasket is good either. It could be blown to another cylinder,
It will detect that, if it blows to anther cylinder, it still has to come out somewhere.

blown to atmosphere, You would "see" this, no need for the kit then.
or blown into an oil passage and that kit would leave you feeling like everything is good.
Nope, you would also see this in the oil.
I mean, you do all your usual test first, visual, etc,,
Look at the oil for water,
look at the rad interior for oil.
Look around the head for leaks,,
but this tester will "sniff" for gases you can't see and should not be there.

You are naturally going to have leakage to the oil pan no matter what VIA ring gap. Do I guess I dont fully understand how the test can distinguish between just normal leakdown to the crankcase via the rings, or a leak to another cylinder or oil passage??

 

[skyhook]

You have me a little confused there, LD1,,
Like I said, if there's a "leak down" past the rings, then thats another story, not the head gasket.
The kit I shown will only test "sniff" for combustion gases in the coolant,
something that you nor I could actually smell.
If you see oil in the coolant, or see coolant in the oil,
then you wouldn't need this kit, you already have an "indication" of a faulty head gasket.
Also, if you have a "leak down" as you put it,, past the so called ring gaps,
you have major problems, in which case, you'll be changing the head gasket also.
In any case, I hope the OP gets this fixed without to many major expenses.:thumbsup:

 

[LD1]

Let me start by saying I dont know how that kit works. You say it is just a sniff test that checks the coolant for combustion gasses right??

Well when I said that IF it passes that test the gasket could still be blown. Just not blown to coolant. IT could blow to another cylinder, or blow to an oil passage. And you said it would detect that, it still has to come out somewhere.....

I dont see how a coolant sniff test would detect a cylinder to cylinder gasket leak?