Cracked Block Testing

[zipsled]

Hello,

Does anyone know if a combustion gas leak detector would work reliably on the 1.0l EcoBoost engine (2016 Fiesta SFE Manual 67k miles)? I've used them on more conventional engines, but wanted to check that I wouldn't be wasting my time using a one on the EcoBoost.
I've had a slight coolant disappearance issue for a couple years where the level will stay at the MIN mark. Replaced coolant expansion tank and "hose" that connects to tank's upper connection 16k miles ago which seemed to have fixed things but looks like not a complete fix.
Had seen TSB SSM47587 - "1.0L Ecoboost - Coolant Consumption, White Smoke And/Or Runs Rough" which suggests "investigation of the integrated exhaust manifold (iem) interface is required. Carefully inspect the manifold port area for cracks.". I've read elsewhere about there being small block cracks that eventually grow and kill the engine.
So hoping a gas leak detector could tell me about the health of my block...while the engine still works (for the most part).

Look forward to your thoughts on this.
Thanks.

 

[Handy Andy]

When you have that kind of condition - where MIN seems to stay around for a while, but when you top it off - it doesn't seem to stay "full"

Look at the driving habits - and tell them to bring it to you when it's hot and you might need to do a "bubble check" where the coolant as it's so hot and from driving - the air in the coolant is part steam and possible combustion gasses too - by unscrewing the coolant cap - that is the pressurized cap so the coolant and gasses trapped in it, would gurgle up into and out from - that release of internal pressure. You might even see it get back to "MAX" by the coolant tank deflating back into the original shape, or drop even further from the displacement of trapped air back to the upper coolant tank.

You might also detect the scents of exhaust and perhaps even "oil fumes" from the escaping gasses - tell-tale signs that you don't need a leak detector, you need a new gasket or at least a top block tear-down to re-torque cylinder head bolts.

But you 're going to re-torque head bolts, just change the gasket - if it's past 100+ miles - and you're having loss of coolant - then the level of coolant and the gasses trapped in it is partly why you have that MIN marker all this time - there is a pocket of air in the engine that foams up when running to carry the heat away. But when it sits that level de-foams and goes back into a pocket of compressed air and gasses - so it tells me the head gasket may be more of the condition than a cracked block, which if this is left unchecked, then not just cracked, warped, may occur.

The check by unscrewing that coolant cap while hot may seem dangerous, - it's not meant to be a complete removal - just a release of pressure and observe the results and look for air traveling back to that tank and the smell of odors from fumes releasing from the trapped air - then you know you have a condition requiring a tear-down and inspection.

• Much of the reason why I say the above is due to the Turbo that is in these motors. I have witnessed several events requiring a much bigger rebuild than a simple tune-up which they were led to believe was needing to be done.
• Partly the problem with gasket failure is from the "more than enough" Air and fuel charge the turbo puts into each cylinder and the amount of tensile strength the block, cylinder head and gaskets involved - provide against that combustion pressure. Looking back further as to the cause is from the needs of the Driver in the conditions they face in everyday driving may require more use of the Turbo than what was expected.
• GDi models have had to overcome the excessive air pressures the compression stroke does and still be able to dispense the fuel charge into the cylinder so as to fire it. To think of this process as the injector nozzle and the fuel pressure required behind it - does the condition become more clear.
• So with the above in mind the excessive pressure caused by that increased charge passed into each cylinder - the gaskets are the most weakest link in the process. Blow-by gasses can spill into both the coolant and the crankcase by rings - oil channels and the coolant jacket - its from that distortion of the seal for the cylinder head, is how this can happen.

 

[zipsled]

Well thank you very much for all that, quite helpful. I'll try those checks you mentioned this weekend.

 

[Handy Andy]

As another hint, look and locate the cylinder head bolts in the motor - and note how the jacket and sleeves "float"

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