3.4L coolant disapering

I have a 3.4L with 230k and am mysteriously losing coolant. it's not leaking. About every 500 miles it will go through the entire resolver and be so low in the radiator that you can't see it. it never runs hot according to the gauge.

 

My Guess is a dreaded Head Gasket Failure.

 

This is almost exactly happened to me with my 2TR-FE at like 157K miles, though it was oil into coolant instead of coolant into oil. There was no damage to the engine block and not even a warped head because I caught it so early.

 

if there was no coolant in the oil when it was changed where would it be going?

 

In my truck, the head gasket blew in such a way that it wasn't getting into the oil. My truck never had coolant in the oil, either. However, the smell of coolant at the tailpipe was overwhelming. The coolant was likely being sprayed into the combustion chamber via the fuel injection system.

 

Blown Head gasket. Have had this before as well... Sorry!

 

Hole in radiator? Do you see any signs of leaks?

 

Check your radiator cap seal. Had this issue with mysteriously disappearing coolant over time. Turned out the seal was deteriorated allowing coolant to escape slowly but not staining anything to make it apparent. $9 cap from O'Reilly and problem was solved. Went through a lot of coolant before someone recommended checking this simple thing.

 

Out the exhaust

 

this the compression per cylinder in psi.

 

Mine does the same thing and has for a long time. I refuse to believe it's a HG leak because my compression is good and the radiator stays full, it's just the overflow tank that loses coolant. No signs of pink crusty dried coolant anywhere in the engine bay. No puddles of coolant under the truck either.

 

I had the same issue recently with my automatic 3.4L 6cyl. Turns out my lower radiator hose clamp was loose on the engine side. Tightened it and no more issues. For now they are tight however they tend to loosen with temperature fluctuations. The clamps are the screw-type ones which you tighten with a flat head screwdriver or socket.

I did replace the upper hose clamps with spring clamps and will do the same with the lower.

 

Anyone with this issue convinced its not the HG should also check their transmission fluid.

 

my trans fluid is brand new with my new clutch ~800 miles ago. With the compression out of speck, I would not be surprised if it is the HG. this is the plug in the cylinder with 132 psi my Toyota neighbor thinks the slight rust color could be from burning coolant.

 

thanks for the help i will probably do a leak-down test and check the hoses. BTW this is my truck:

 

Don't forget the "coolant bypass tube" when there is no other detectable leak source.
https://www.tacomaworld.com/threads/coolant-gone-no-leak-visible.525167/#post-16740632

 

nice truck