I have rebuilt my S4 TII, and apparently have forgotten a crucial step!

According to the manual, the coolant system takes around 7.7 Quarts, so when around 3 gallons had been put into the system with out it over flowing, something seemed very wrong.

I opened the oil filler cap, and a foamy mix of oil and coolant was about to spill out. I took out the dipstick, and milky coolant-oil mix nearly spewed out.

So obviously a full tear down is necessary, but I am wondering where to start, as I followed engine rebuild procedure closely. What could be causing there to be zero barrier from the oil and coolant systems?! I was under the impression that there is a very low possibility for the two fluids to even meet. I want to know what to look for when I tear down the engine. What could be causing this catastrophic failure?!

Any input is appreciated!!!

(attached is a picture of the horrible coolant-water-oil mix that came out when I drained the oil)

 

Also, there was a steady leak from behind the pulleys, from what looked like the bottom of the water pump. Not sure if this is related or not.
EDIT: Starting to suspect a freeze plug in the front cover, but could be wrong.

 

You have open or leaky freeze plugs in the front iron.

 

I can get to these without pulling the engine correct?

 

Yes. You can just remove the front cover. Upon reassembly, remember the Torrington bearings so keep the clutch pedal pushed down (2 x 4 and seat moved forward).

 

Perfect. Thanks for all the help, I will get started on this right away!

 

So I removed the front cover, and both freeze plugs were in place and seemed intact. Are there other freeze plugs deeper into the engine that could be causing this? Or is it possible that even though the plugs were there, they were still releasing all of the coolant into the oil? Here are some pictures of the plugs:





EDIT: Just did the water test by pouring water through were the water pump would be, all of it came out from what looks like the center iron area. Trying to upload a video right now

 

I honestly can't recall if there are freeze plugs accessible to the oil gallery on the center iron. My suspicion is yes.

The other possibility is a damaged water o-ring or cracked iron.

 

Center has no core plugs to speak of. Water jacket core is accessible from both sides so it would be adequately supported for the casting process. The core plugs in the front housing under the front cover would be the only place.

If it were a failed water O-ring, it would have to have taken out the outer land as well (difficult) and it still should not leak faster than it could get poured in.

I wonder if the center could have corroded through, or given that the oil "crankcase" runs up near the upper dowel area, if this could be a rare case of intermediate housing dowel area crackage.

 

Here's a link to the video of the leak:

 

Well, no matter what, you're going to have to R&R the engine to find the leak and repair it. Should be more visible with the oil pan off.

...Hmm. I wonder what would happen if someone used the wrong bolt at the point of the passenger side motor mount and cracked the casting there from bottoming it out.

Just for giggles, I'd pull the oil fill tube off and add water to the engine and see if I could see anything down in there. But the first step to making it right is going to be removing the engine so it's not really important to do. If it was something silly like a throttle body coolant hose routed to the breather port, it wouldn't flow like that until the engine was FULL, like water pump housing installed.

 

I'm in the process of removing the engine right now. Just curious, where are all of the breather spots on the engine? I know there's the one on the center iron next to the oil fuller neck, and one on the filler neck itself, anything else?

 

Nope, that's it. Air goes in the nipple on the housing and out the nipple in the oil fill.

 

Ok we're good there then, I left both of those open. Starting to think either a pinched seal when I was putting it together, or a cracked center iron

 

Found the culprit. Wow.

 

WOW. How does that even happen?

 

Engine ever got below freezing with coolant or just water inside?

 

Yeah we had a really cold winter, but I made sure I had drained every last bit of water out, I guess some stayed put lol

 

I had a water freeze incident once but the engine was fine. The radiator didn't fare very well, but the engine was fine... I guess the luck plane was tilted in my favor.

 

I guess the moral of the story is always use anitfreeze!

 

Holy crap, that will do it!

This is one I had to deal with. Owner kept topping the car up with water until there was just water and no antifreeze.