Need less to say I've been doing tons of research on coolant leaks specifically combustion related.

I'm lead to believe I have a cracked block yada-yada (slipped liner/ white smoke/ waterfall dash/ mystery fluid drop)

I bought a combustion test. Ran it twice with thermostat completely open and the results are negative.

Not even sure if I'm asking this correctly but can coolant leak into oil chambers that can't be detected by this type of test?

Temp doesn't go above 195. I also flushed and bleed, heater core included to try and rid bubbles.

Truck runs cherry. No codes except Amigos.

What can this be?

Any input would be appreciated. Thanks for welcoming me to the forums. This is my first post!

 

Very often head gasket leaks are external so there would be no combustion gasses in the coolant. The weak spot in the head gasket is at the rear of either head. That is where a water passage is very near the edge of the gasket, and there is only a very narrow bit of gasket.

The best thing to do to track down a coolant leak is to get a cooling system pressure testing kit from any of the major auto parts chain stores. They will loan it to you for free. Follow the instructions and pressurize the system as specified. Any leaks should then be revealed.

 

If it were me I'd remove all of the spark plugs and then borescope the bores internally and then run a compression test without any spark plugs as fluids can also raise the pressures as well. It doesn't matter how many revs turnover on each test as the ultimate cylinder pressure is the ultimate pressure achievable. Once done then report your findings on the forum. IMHO it does sound like a head gasket has blown.

https://www.google.fr/search?q=pictu...hrome&ie=UTF-8

Just ensure the borescope camera can fit through the spark plug hole.

 

Just wondering what if your leak is not in the combustion. It could be other places. If no misfires, youre good. If you have leak in the combustion chamber, most likely you will overheat since it adds more pressure coming from the crack then into the cooling system. If you are not overheating and you still have waterfall in the dash then you have a better chances you are ok. Just get that air out. White smoke could be just vapor especially during cold season. Slipped liner? That need to be checked, though it could only be a stuck lifter, better oil combination etc, Cheers

 

Leak down test. YouTube it.

 

An Autozone just opened up on island (Thank God). I just called they have a 24 piece kit in stock.

I'll go this route for now since it's available and affordable ($250 up front deposit and returned upon equipment being brought back).

Thanks a lot mln01, this will narrow down possibilities~

 

And would I use a borescope to reveal cracks or coolant, all of the above? Never used one before.

I'm going to go the coolant preasure test for starters and then compression after that. I'll consider a borescope as well thanks.

 

Thanks for your input. Pardon my ignorance I've never dealt with a vehicle with misfires before but what would the symptoms be?

A little more history on vehicle:

I just acquired it about a month ago. It had I'm assuming original thermostat, temps got upwards of 220 every time I drove it so it may have had overheating issues prior to my ownership, I don't know. However; in my possession nothing crazy has happened. Just swapped it out for 180 degree unit last weekend. Numbers are great.

I did buy some hyper-lube to add to the crankcase to quiet noise and enhance seals etc, but was steered away due to reading their safety sheet that it becomes hazardous when mixed with acid aka coolant, so I passed. Weird how it states 100% petroleum based though hmmm. Is this what you mean by oil combination or just trying different brands/weights? I'm running Rotella 15-40.

Anyway, things are likely pointing to head gasket now that I know leaks can be undetected due to exterior breach. I'll give the tester kit a shot and report back.

Have any of you done head gaskets and how difficult it it? I'm not the most knowledgable mechanic but I sure as hell aint afraid to get my hands dirty and endure whatever frustration comes my way.

*edit*

What's also strange is this is a newer rebuild, 30K miles or so. Am I wrong or would you think that an engine would hold up to NOT have a cracked block at this rate? I guess if it's had high temps this whole time it could be possible but a head gasket would be more quickly to fail.

 

You would know if you had misfires. Rough running, spitting and sputtering under load, and the check engine light will flash until the situation stabilizes.

The fact you don't have misfires indicates no internal HG leak and probably no internal cracked block type leak. The cracked block scenario plays out similar to an internal HG leak, coolant enters combustion chamber from behind liner causing misfires from fouled plugs. No misfires, no problem here.

You've also found that you have no exhaust gasses in the coolant which can also be a symptom of a head gasket leak. This is where the HG fails between a cylinder and a coolant passage. Exploding gasses find their way into the coolant passage. That is what your "combustion gas" test proved.

Did this start after you changed the thermostat? It's possible your first attempt at bleeding did not fully work. Very common in fact that a bubble remains in the system and then burps out. A small bubble in the system will give the waterfall sounds.

It often takes more than one try to completely bleed the system. I make sure by looking in the bleed hole when the engine is stone cold. If there is any room at all in there then you have found a small amount of air. Top it off through the bleed hole each morning with cold engine until it no longer needs it.