hey guys, I bought a stock virgin d16a6 engine today, spun freely and the price was right, from an automatic civic si.

I put it on the stand asap and started tearing it completely down, as I intend to rebuild the block for boost. As I got it apart I noticed how mint everything was, bearings, cylinder walls, crank, all minty smooth.

Got the water pump off expecting to see some corrosion as the motor came from a junked car with no idea how long it sat (although the car was new to the yard so possibly not even a week) but the water pump looked ok and no corrosion on the block side passage.

Last thing I pulled off the motor, was this plug into what i believe is a hole into the water jacket?



Just CAKED behind that plug with grey grit, the plug itself had a tablespoon of the gritty grey paste stuck to it, and with a screwdrive I picked a bunch more out.

What the heck is it from and why does it look so clean from the water pump passage?

Would a water hose clean this up? Im more curious how it built up such a thick gritty paste in the coolant system of a seemingly perfect longblock

 

Hard to see since I'm on my phone but that block looks painted. If you didn't do that I'd be willing to bet that the front side was covered in grime and that's just the leftover that wasn't scrubbed off prior to paint.

EDIT - that plug should be brass in color. Looks like it got painted with the block.

 

The block pictured isnt mine just a picture to show what plug Im talking about. My block has surely never been painted, and my plug was steel.

Just curious why there would be such a thick grit behind that plug, Ive openned a few motors with no corrosion there, just curious if I should be worried or do anything extra to clear that out

 

Excess hondabond?

 

It's silicate drop out from using coolants with silicates in them for too long. It falls out of the coolant once it ages and sits in the bottom of your cylinder water jackets (behind that plug). Use the silicate-free Honda blue coolant and this won't happen again. Of course the same stuff is probably inside your heater core and radiator as well. :\

http://www.sancarlosradiator.com/ant....htm#Silicates

 

^good info

 

I'm going to second this.

I have seen the drop out on my radiator before and it looks gross as all get out. Definitely get what this guy was talking about. That's what I plan on using when I put in my fresh radiator. You can probably just clean out the motor and be fine.

 

Very informative thank you. I did not no coolant did that, although I change mine regularly I still dont want that forming and see that as a good reason to switch to the Honda blue coolant Ill look into that.

Gladly I dont think any of that fall out is in my cars rad/heater core as my car has been flushed every 25k miles since new.

This engine came out of a junkyard car, so I guess if I jet wash the block I will be good

Cheers