Hey Guys,
Just rebuilt the engine on my 04 RX-8 (MT), or at least tried to. Putting everything back together I noticed a small crack in one of the tension bolt housings on the rear end plate (the very back of the engine, in the parts manual this is referred to as the rear housing). I was already at my budget limit, so I put some JB weld on it and installed it anyway, when I really should have replaced the whole plate. When I started the engine, there was clearly a massive coolant leak into the rear combustion chamber, so much so that I can rotate the engine (not running), and coolant drips out of the rear exhaust port.

I'm just wondering if anyone has experience with cracks in said end plate, and how that crack, which looks to be just in the tension bolt housing, could be leaking coolant into the combustion chamber. It doesn't really make sense to me, but there seems to be no other source of the leak. I'll probably have to tear into it again and replace that plate, but I just wanted to cover all of my bases first.

Thanks!

 

Coolant runs thru the irons and housings, obviously that crack extends into a coolant passage. The first order when rebuilding any engine is to check for things like this.

 

I did check, and the crack stopped before it even hit the endplate itself. I suppose it probably grew when I torqued the bolts down.

 

I just have got to ask. Why would you use a cracked iron at all when rebuilding and unless you used a die to track how bad and how far the crack realy went you really didn't know how bad it was.

 

So you intentionally used a cracked iron? That was smart, I Hope you get it right next time.

 

Never underestimate the power of wishful thinking and being completely broke.

 

Die penetrant is cheap, for that matter a good magna flux wouldn't cost much at a engine builder if it was questionable.

Its a whole lot cheaper then the cost of another rebuild if parts get damaged due to carelessness.