Issue fixed, cracked radiator cap

Nope! 2 dealerships did leak down test on mine. Passed everytime!

Friend who owns a shop... spotted the problem months before, by ear.

I picked him up for lunch one day, asked how long have your head gaskets been bad? I literally laughed, no probs with head gaskets, he said yah, there is!

He said I heard water!

He was right, after all the leak down tests, he said scope the cylinders, I TOLD YOU your head gaskets are bad! He was half right, one head gasket was bad.

Buy a dang scope, there cheap, you can even get one to connect to an android phone for $20 on ebay! If you suspect a head gasket, pull a spark plug and look, its in your face obvious if you have a bad head gasket.

People spend a fortune on diags, its really a simple process...

You either see water in oil, coolant in cylinder, or scope the cylinder, if it looks like its been freshly steam cleaned... it has! By a trickle of coolant being burned off during ignition!

 

Some are really not that simple. I have seen some really weird blown head gaskets before. Some do not manifest themselves in "steam cleaning" the cylinder.

 

Kool, please share. Literally, it will help everyone diag in the future.

 

Putting 175 psi in through the spark plug hole and rotating the crank to close valves and watched for bubbles is the only way we found a leak once too.

 

You're getting your tests confused.

Simply going off the appearance/cleanliness of a cylinder could result in false positives. There are no false positives with the block testing kit I'm referring to.

Spoken like someone who does not wrench for a living.

 

Take the radiator cap off. Start your truck. Look in your radiator. Watch for bubbles. If you see bubbles you have a bad head gasket. This is the easiest and best way to tell.

 

This is also a valid test. Simple, and you wouldn't think it works, but it is valid.

 

In my experience you don’t even need to take the cap off, the bubbles will go into the overflow resi and you will see them there....and again mine never went much over 205

 

My guess is you do not repair vehicles for a living. Neither do I.

It would seem you've been the victim of an '05 / '06 4.0L head gasket problem. You may have learned a thing or two about this issue from that experience, but the way you've been rambling on in this thread, it's as though you are the only guy on the planet who knows anything about blown HGs.

Years ago, a Ford engineer told me that head gaskets fails in multiple ways:

chamber to coolant, coolant to oil, oil to coolant, coolant to chamber, chamber to chamber, and oil to the outside of the engine.

This may be why so many here have experienced success diagnosing HG failures using methods that you believe are not valid. Their type of failure was different than yours. What works for one situation may not work for another. The Petersen method that I presented may not be the holy grail in all of these cases, but I'll take the word of an experienced L1 tech over a diyer forum blow-hard any day.

 

This is how we found for sure that my 2005 had a head gasket issue at 136,000 miles since it didn’t show on any other tests. When my motor was torn down to the heads my gasket had a very small hole in the gasket. It was showing a white crusty material around the overflow bottle filler.

 

I have had every one of those failures, on my 1GR's. Literally.

 

I had a head gasket leak on my 88 toy 4x4
coolant would leak out the block at the head only when engine was hot

no bubbles in rad
no exhaust in coolant
no oil in coolant
no coolant in oil
good compression

on a cool night when engine was hot with AC on for a bit of load, you could see a little wisp of steam escape at the head gasket mating area

 

1) Coolant to outside leak
This one’s not as easy to spot as some of the others, especially if the leaking coolant dribbles to the ground while driving, or evaporates, and leaves little trace of where it is leaking. If a head gasket fails between a water passage and the outside of the engine, the cooling system will eventually run low on coolant. When the coolant level drops too low the engine will overheat.

2) Compression leak to oil galleries
If the head gasket fails between the cylinder and an oil gallery, compression will enter the oil system and pressurize the crankcase. Hot compression gasses will compromise the lubrication of vital bearings, such as the crankshaft main bearings. The same failure will also allow the piston to suck oil into the cylinder, where it will be burned off as part of the combustion process. This will eventually cause a drop in engine oil levels, and will also cause blue smoke from the exhaust from burning oil.

3) Water to oil leak
If the head gasket fails between an oil gallery and a water passage it will allow the engine oil and coolant to mix. This will result in contaminated oil (the white milky sludge or "milk shake" associated with a blown head gasket) and a compromise the cooling system.

4) Compression leak between cylinders
If the gasket fails across the fire rings it can allow the compression to leak from one cylinder to the next. This causes a loss of compression, and sometimes allows exhaust gasses back into the intake, depending on cam timing. This sort of head gasket leak typically results in rough running, misfires, and a loss of power.

5) Compression to outside leak
This type of failure is not as common as the others, but some engines are prone to the head
gasket leaking between the cylinder and the outside of the engine. This allows some of the compression to escape out of the engine, causing a ticking noise at idle that can sound like an exhaust leak. You will also experience rough running, and a loss of power.

6) Oil to outside leak
This one is fairly easy to spot, and if the head gasket fails between an oil gallery and the outside of the engine you will be able to see the oil leaking down the engine. While not as immediately dangerous as other types of head gasket failure it will still require repair as it will only get worse over time. Depending on how the engine is designed, this sort of leak may result in less oil pressure getting to an overhead camshaft. Keep an eye on the engine oil level and don’t let it run low.

7) Compression leak to coolant
If the head gasket fails between the cylinder and a water passage it will allow exhaust gases to enter the cooling system, resulting a pressurized cooling system and overheating. Often times this presents itself as a radiator hose blowing off its fitting. This, in turn, can result in a damaged radiator, hoses, and other cooling system components. This leak also results in a drop in coolant level, causing overheating. The same failure will also allow coolant to get sucked into the cylinder, where it is then burnt off as steam, or white smoke out the tailpipe, and a sweet smell. The steam that is burnt off can also cause lead to damage in the catalytic convertor as it exits through the exhaust system too.

https://haynes.com/en-us/tips-tutorials/7-different-ways-head-gasket-can-fail