So, to determine the health of a head gasket between two cylinders, try doing a bubble test.
If you believe you have a leak, but just cannot find it, doing a bubble test may be the answer.
Because, there are occasions when either a compression or leak down test, will not show a very minor leak. For example, when the leak is between the cylinder sealing surfaces.
So, why do a bubble test? Well, when you do a leak down or compression test, there is always some leakage. It may be from rings or valves, so you may have to do, next level testing.
How To Confirm A leak Between Two Cylinders On Any Engine
There are many ways to do a bubble test. Each way can find a different problem in a different place. But, for this blog post, we are going to talk about a cylinder head gasket leaking between two cylinders.
It is done in conjunction, with a cylinder leak down test.
How To Do A Bubble Test ( In Six Easy Steps )
- The first thing you have to do is, remove all the spark plugs.
- Use a cylinder leak down tester, and hook it up to one of the cylinders.
- Apply 100 psi of air pressure, to that cylinder.
- Use another hose from a compression tester, and hook it up to the adjacent cylinder.
- Place that second hose in a container of water, and look for bubbles in the water.
- Bubbles in the water, confirm sealing issues.
So, all cylinders need to be done. Since, there may be an occasion where, the gasket leaks only in one direction. That is the reason for, the bubble test.
Though this condition is rare, it must be understood that the purpose, is to diagnose a problem. Consequently, no assumptions or short cuts can be taken.
So, there is no pressure reading with the bubble test, only a visual confirmation of bubbles in the water.
Helps Find Very Small Leaks, In Many Places
- Sometimes there is a very small leak in a cylinder wall. ( From cracks or perossidy in cylinder ).
- Incorrect cylinder sleeve installation. ( Possibly too much crush, causing a cylinder to distort and leak ).
- Blown Gasket or leak between cylinder. ( Gasket, cylinder damage or cylinder head damage ).
- Even a (MLS) gasket leaking internally. ( Because of multiple layers of material ).
- Damage to a cylinder from hydro-locking. ( Liquid entering a cylinder ).
So, as you can see, doing a bubble test, can find issues you were not even looking for.
Conclusion
So, if you really believe that there is a leak, between cylinders on your engine, try doing a bubble test. The primary use of this test is, when all other tests fail. Finally, easy to do and you most likely already have the necessary tools.
