I've got a 13BRE in my FC. Haven't had any issues like this prior to the rebuild. The only difference is the LIM gasket is a OEM one from Mazdatrix. Prior it was a home made cut-out one. I haven't totally ruled out a coolant seal but I find it unlikely since there is coolant in all four runners and I don't see any signs from the coolant system besides the lose of volume. Mostly in the center iron ports. I also don't see how there would be coolant in the intake ports if it was a seal. The engine hasn't seen boost. Only idle for about 1.5hrs time total.

One question comes to mind that I can honestly answer. What the holes above the intake ports on the intermediate housing are for? Any input would be great. Just don't give me any bad news.

 

Emissions / oil pan venting is the opening on the intermediate iron.
The rotor housings on the earlier turbo engines had coolant coming out the rear rotor housing through the intake for the turbo. There where o-rings on both the front and rear housings that need to be replaced when removing/installing the LIM.

 

The RE doesn't have the coolant flow through the LIM like the Tll S4 does. I found out the issue though. Pressure tested the coolant system and it failed. There was one spot on the coolant seal wall to one of the plates that I found to be iffy. I went ahead and called it good, but forgot to look at it again after I had the plates lapped. Would a failed coolant seal wall cause leakage into BOTH housings? That's what is baffling me.

 

it can but it takes a large leak to run from one chamber into the other through the exhaust manifold.

smaller leaks are difficult to see on a pressure test, larger leaks will show up quickly.

 

What about the theory that the block had so much air in the coolant passages in the top of the engine which would keep that area from being cooled properly and causing the seals to cook? Has anyone ever seen evidence of this?

 

no

at least not the top of the seals, it may cook the compression side but you'd be surprised how resilient new seals are. if the engine got REALLY hot then the seals can liquify, but we're talking 300F+.

point is, if it failed a pressure test just tear it apart and find out.

 

No doubt. I'm so anxious to see what failed.

 

Still scratching my head with this.
I tore the engine apart and didn't find any real obvious culprits. All of the inner coolant seals were still in perfect condition. All but one of the outer coolant seals were perfect as well. The one that wasn't had strange signs of damage. It had about a 4" long section that looked liked just the very outer edge had been pinched and caused the seal to start splitting. I don't know how else to describe it. I'll try to take a close up photo of it. I had also found coolant in only one of the chambers on the legs of the rotor housings where it opens up to the exhaust sleeve. Other then that, I was able to still scrap off quite a bit of carbon and rust out of the coolant seal grooves which exposed even more pitting in the iron. The rotor housing also have pitting where the seal rests.

Here's my new theory based on what I've found. The outer seal leaked into the chamber or the rear rotor housing leg and into the combustion chamber. Would it be possible for the coolant to make it's way into the combustion chamber of the front and rear housing fighting against the exhaust flow and the gasket? The engine what only idling before I took the LIM off and found the coolant in all four intake ports.

Lets here some thoughts.

 

look around the spark plug bosses and exhaust port inside the coolant passages for pitting. if the electrolysis is bad enough it can allow coolant to get into the engine even if everything else is perfect. the outer seals can't really allow coolant into the engine so i would disregard the chafing. or are those an aftermarket inner seal? (hard to tell since all OEM seals are square/rectangular)

 

Still never found anything wrong with the irons and housings. I decided to get a pineapple racing coolant pressure tester and reassemble the block with just the old coolant seals. I reused the tension bolt seals as well to not mess with the new ones yet. After pressurizing the block I had to tighten down the tension bolts a little to stop some leakage there, but so far it is steadily holding 15psi without any internal leaks. If it holds over night I'm planning on reassembling the block properly and testing it again. Handy little tool from Pineapple Racing.

 

Update:
Back to original problem. I rebuilt the engine with oem coolant seals. Pressure tested it with the pineapple tester which it held 20 psi perfectly over night. Reinstalled the engine and now it's still dumping coolant into the the combustion chamber. So much that before it even gets to normal running temp, the radiator hose swell up and coolant starts spitting out of the overflow resevoir. I'm out of ideas and really frustrated. My only guess is that the plates or housings are warped. There's no other explaination. I neither have the time or money for this anymore.