2004 4.0 Head gasket issue?

[steamyfirefighter]

I have an 04 4Runner with the 4.0 in it, I bought it 3 years ago with 138,000 miles on it bone stock. I have since put a 3in Toytec lift on it, added 4.88 Nitro gears, Shrockworks bumper and rock sliders, 9500 Superwinch, 285 70 R17 STT Pros, and MT Classic wheels. She is my daily driver and we wheel it almost every weekend. I keep meticulous maintenance records and fix any tiny thing that comes up. My new problem that I have is while at an overland rally 2 weeks ago, my hubs checked the radiator level and we couldn't even see the fluid. (I have NEVER overheated her or even came close) We topped it off, went on a trail drive and we are finding that it will push fluid into the reservoir but will NOT pull it back. We changed the radiator (we did find a tiny pinhole leak) cap and top and bottom hoses and the problem is still the same. I had the coolant checked by two different places and they both say that it is the head gasket. Oil has NEVER had any traces of coolant. Could the hole be sooo tiny that the only symptom of a bad head gasket is within the coolant? There is 195,000 miles on it now. If I have the head gaskets done what else can I do to make sure it wont happen again?

 

[Johns06yota]

I have an 04 4Runner with the 4.0 in it, I bought it 3 years ago with 138,000 miles on it bone stock. I have since put a 3in Toytec lift on it, added 4.88 Nitro gears, Shrockworks bumper and rock sliders, 9500 Superwinch, 285 70 R17 STT Pros, and MT Classic wheels. She is my daily driver and we wheel it almost every weekend. I keep meticulous maintenance records and fix any tiny thing that comes up. My new problem that I have is while at an overland rally 2 weeks ago, my hubs checked the radiator level and we couldn't even see the fluid. (I have NEVER overheated her or even came close) We topped it off, went on a trail drive and we are finding that it will push fluid into the reservoir but will NOT pull it back. We changed the radiator (we did find a tiny pinhole leak) cap and top and bottom hoses and the problem is still the same. I had the coolant checked by two different places and they both say that it is the head gasket. Oil has NEVER had any traces of coolant. Could the hole be sooo tiny that the only symptom of a bad head gasket is within the coolant? There is 195,000 miles on it now. If I have the head gaskets done what else can I do to make sure it wont happen again?

From some of the other threads on here it seems the issue is that once the engine is to temp it creates a small gap just big enough for coolant to come into the cylinder but not cause too much blow by. To my knowledge if you have the head gaskets replaced they should be putting on the newer design which I believe is larger. (they created a new design after the 11th month of 2005) This is why most of the head gasket issues are for the 2003-2005 and early 2006 model years

 

[rumfoord]

How quickly do you lose coolant? I'm getting the impression its quite a bit quickly? If so would be more than a tiny hole. Do you have a check engine light? Do you notice a rough start/idle after starting when engine is cold or white smoke out of the exhaust? My head gasket went and these were they symptoms I had. Check engine code read a misfire in cylinder 6.

Someone else did point out that I could blow another way though. See below post.

http://www.toyota-4runner.org/4th-gen-t4rs/254971-2005-v6-4runner-over-heated.html#post2972285