First Datsun Breakdown L28

[DatsWeird]

Hello all,

After some spirited driving I stopped at a gas station. Went to restart and it turned over once and all electrical clicked off. Popped the hood and played with the battery cables several times with the same repeat situation occurring. Finally turned over slow and fired while spitting out a couple quarts of steaming coolant from the tailpipe  :confused:

Driving home used up the rest of the coolant hitting max temp right as I pulled in the driveway. Thinking it was the head gasket, I compression checked it. 180-180-175-170-180-180. Pulled the intake and found this: 

Intake:

Exhaust:

 

All intake and exhaust are fairly similar. I could scrape the white off the exhaust valves with my fingernail. Looks like milky water on the intake valves, making me think it was inducting water from the fuel injection intake that does have water going to it: 

 

Motor has 180k, the water sensor on the intake is pretty crudy, is it possible some kind of seal failed and was allowing water to flow into the intake? Not sure if the piston could push water back into the intake under a fluid hydraulic lock situation? No water in the oil, everything else looked good, piston tops were all shiny clean. Any seasoned datsun owners experienced anything like this?

[Draker]

Too late for a coolant system pressure test... that would have told you something. Now a guessing game!

 

Compression numbers look fine.

 

What do the spark plugs look like?

[DatsWeird]

Spark plugs were all wet and clean like they were burning water. Didn't think about refilling it with coolant for that test. I did the head gasket 10k miles ago, head was in good shape and flat although I never decked it or the block.( Inspected by a machinist buddy) Had a visible gasket tear between 3 and 4 cylinder, possibly why those compression numbers are slightly lower than the others now(ring wear from water?) It did have water in the oil last time, bought it that way. 

 

Used a felpro gasket and torqued head bolts to turbo spec in sequence. Originally was thinking the reused factory head bolts may have stretched from age or I should have used a Jap Ishino gasket.

 

Finding water in the intake, all pistons clean, and good compression is what's throwing me. Last time I could see shiny pistons on 3 and 4. Rest had a lot of carbon. Very little compression between the two cylinders.  I know very little about this fuel injection system and why it has water going to it.

[datzenmike]

 

 

If the intake leaked..... how would the water get out in front of the throttle plate?????

 

 

 Do you have a 'cone' filter on it? Any other mods to the intake side?

 

 

Inspect the air delivery hoses to the MAF and all the way to the throttle body. Is there a split rad hose or even a rad leak that would spray coolant on them that could be sucked in???

 

 

 

The heater hoses on my '64 slat six were near the snokle on the air filter. When revved up it would spray directly in and a big cloud of steam would follow me.