Failed MHG install? Now what??

[rbutton]

Here's some photos of the failed OEM head gasket after removal.
You can see that it failed on cylinder 6 and that each exhaust coolant channel seal has been deformed.
Cylinders 2 and 3 look OK to me, so not sure those "cracks" are much of an issue.

Cylinders 6 and 5

Cylinders 4 and 3

Cylinders 2 and 1

 

[hvyman]

A cracked block is a cracked block. If you dont have problems right away you will down the road.

But if you want to run it im all in for seeing carnage pics in a month or 2.

 

[rbutton]

Update -

Before going in to replace the MHG with a composite HG I had to clear-out the coolant flush I put in. While doing this I noticed tiny bubbles/foam coming out of the radiator while the engine was running. Even after flushing the system with water I still saw tiny bubbles coming out at the top of the radiator. I'm assuming this is a sign of the cylinder blow-by that was causing my coolant to be forced out of the system?? Anything else that could be causing the bubbles?

Before taking the head off I tested the cylinder compression again while cold. Here's the readings -
1-185psi, 2-195psi, 3-195psi, 4-185psi, 5-200psi, 6-200psi

I thought cylinder compression tests were supposed to indicate the health of the head gasket, valves, and rings. Still perplexed as to why I'm getting really good readings with a "bad" MHG.

 

[rbutton]

Here's photo of the plugs I removed. Cylinder #1 on the left and #6 on the right.

What's going on in cylinder #6? I've never seen an insulator that brown before.

 

[IJ.]

 

[toyotanos]

The plugs tell you that #6 Isn't having proper combustion. It could be many things, but based on the information we've been given, as well as the picture- it seems like a head gasket that is not sealing correctly.
You have 2 options:
1- Pull engine and have it machined (and hope it turns out good)
2- Replace engine (better option, given the cracks in the block)

Also, don't use those Bosch plugs- they are garbage in an older Japanese engine. Use some denso PQ20R-U plugs (originals), or NGK's (can't recall the part number at the moment)

 

[CRE]

I thought cylinder compression tests were supposed to indicate the health of the head gasket, valves, and rings. Still perplexed as to why I'm getting really good readings with a "bad" MHG.

No, nothing's certain... A leak down test along with a compression test and testing the pH of the coolant would tell you a lot more.