1990 S5 N/A motor, 105,000 miles on it...

break #2

I have torn apart approximatly 12 motors now, and have never seen a coolant seal blow through the side of the retaining wall like that.

Been there. Actually saw it on a S4 high mileage motor. Sh** happens, just one of them "thar thangs" https://www.nopistons.com/forums/pub...DIR#>/wink.png

I have never seen a coolant seal blow......ever. I hear about it but never seen it happen.



So what do you think that means???

I was about to say detonation... but then I saw it was an N/A motor...

strange.. Something bad must've happened on the combustion side of things..



Those two breaks seem to be around about where the apex seals would be sitting right about the time combustion would start to take place.

one more pic of the whole thing

I see it all the time.

It happens when you overheat the motors. When I know a motor has been overheated, I plan on replcaing at least one iron because of exactly this. This is the cause of the bubbles in the filler cap, as combustion gases physically push pass the seals/cracks and into the coolant poassages.



http://www.mazdatrix.com/faq/sidehsgs.htm

yeah i pulled a t2 front to build a shitty motor with and it was broken there!

detonation doesnt do this, this happens when u overheat for prolonged period of time. and not chaninging coolant on time weakens teh casting also.