V6 1GR-FE Head Gasket Failure

Hi guys. I bought my '07 Tacoma used last year with around 63k miles. I've put about 10k miles on it since then. Recently, the outside temperature has been dropping, and for two days I noticed some rough idling on a cold start that quickly went away after the engine warmed up. My Ultra Gauge then displayed a warning for an imminent CEL (P0305 - misfire in cylinder 5). That same day, after a cold start, the idle was very rough and the CEL came on. This time, the truck ran very rough even after warming up. After pulling the plug on cylinder 5, I could see coolant inside. I'm assuming the head gasket is the point of failure.

From the searching I've done, it seems that many head gaskets have failed on this engine, mostly with the 4Runners. Apparently Toyota started using a new part number sometime around 2006. I'm thinking I will replace the gasket myself, although I haven't seen anyone create a guide for this. Any advice is welcome. It was disappointing to have this happen with somewhat low miles and I wish Toyota would have done something for all of the problem trucks. Just wanted to share the story...

 

That's sucks.. Sorry to hear. I think I remember reading about early 1gr hg problems.

 

Just an update in case anyone encounters the same problem:

Success! I have finally gotten my truck back together and it is running well. My ultra gauge shows a warning every now and then for Catalytic Converter below efficiency threshold (P0340) but I'm guessing that the exhaust is not fully sealed or an O2 sensor got banged up. No CEL yet so hopefully that problem works itself out.

It took quite a bit of time to do this work, mainly because you have to drop the front diff (assuming 4x4) and remove the steering rack and oil pan because the oil pan has to go on after you re-seal the timing chain cover. This is due to the fact that the oil pan overlaps the cover. There was some pitting in the head going from one of the coolant weep holes to the cylinder, so I had both resurfaced at a machine shop. I followed the procedures in the FSM (you can find it on custom tacos) and at these two links:

https://www.tacomaworld.com/threads/wishbone-runners-build.238998/page-16
I bought parts off rock auto, fluids off ebay, and tools at harbor freight. My dad and I welded some scrap metal together to hold the crank pulley to get the 185 ft lbs. Overall, I would say it was a good learning experience but if I had to do it again I might consider hiring someone to do the labor. If anyone is thinking of attempting this, I can share my experience.

 

Congrats on your success!