There is one other remote possibility for pressure remaining in the system when the car had not been run for weeks - if the ambient temperature had gotten very low between when it was run last and when you then opened the cooling system at a significantly warmer temperature. That would cause the coolant to expand and some small amount of pressure to be present when you opened it.

 

^ that possibility does sound rather remote. I'm going with the retained air - it doesn't take a lot of pressure to splash the coolant out the cap, just a moderate amound of volume moving through the cooling system. If the air is trapped somewhere other than the filler neck then that means a splash.

As for the test, sounds like an excellent plan.

Dave

 

Yeah the ambient temp was basically the same. Hooray for NC weather.

 

Forgot about this thread. . .

Update: It was coolant sneaking into the front rotor housing. The engine's out, stripped down, and on it's way to Kevin at Rotary Resurrection for a rebuild (in the back of my Mountaineer since I'm close enough). I've got a huge list of things to take care of while the car is down but the car should be up in 5-6 weeks better than ever.

 

Same thing happened to my `94. Same rotor housing too. Engine is out right now & I am taking things off of it to re-install on the other block. I hate coolant leaks!

 

Sorry to hear you're in the same boat Speeder165. Good luck with your project.

 

Thanks & good luck with yours also. I have heard of Kevin at RR. Almost took mine there but since I am a DIY guy, I figured what the heck! Have 2 1st gens I have done engine swaps in. This is my first 3rd gen. Boy do they have a BUNCH of stuff on top of that motor! Wanted to save some money as I am unemployed at this time. Automotive careers are bad news nowadays. Maybe soon we will both hear the whine of that engine & that familiar Pssssssssss as we shift gears! Looking forward to it!

 

Yeah I'm a DIY guy myself. I've never let anyone else do any work on my car so far, but with all the little things that can cause an engine to die in short order I decided to let a pro do it. What's nice is that it's giving me more time to focus on other little things that need to be addressed (eg. airpump idler pulley, delete P/S, install fuel surge tank cover, install sway bar mount reinforcement, DIY motor mounts, oil pan brace, refreshing coolant hoses, re-wrapping engine harness, cleaning up wastegate port, etc, etc, etc, etc).

 

So I went over to RR last weekend. Quite the sight over there.



Diagnosis: Blown coolant seal on front rotor, chipped apex seal on rear rotor (I had no idea about this), shot main/rotor bearings, and carbon galore. Rotor housings are reusable but not in the best shape.

Here's a picture of the sucker who was causing all the issues.



Now it's off to KDR this weekend to go pick up a late model rebuilt transmission.

 

Man! Kevin has a nice "stash" over at his place!! Very nice!

That broken "rubber band" makes me cringe. LOL! Still spending money here on account of it. Mazda is sucking me dry. I just keep looking forward to the day I will have the car back out on the road & driving it. It will be worth it.

To sunny days & open road ahead!

 

Hm. Did Kevin or anyone else have any guesses as to why this particular piece at that location decided to give way? Almost looks like a hot spot or something that burned through. A few guys I've talked to say that poor cleaning and assembly errors will contribute to a coolant seal failure like the one you pictured. How many miles were on the engine and who put it together last time if you don't mind me asking?

 

Kevin didn't say much more than "well there's your problem right there". It's certainly a possibility that it's on the cast iron heatsink ex mani side of the engine but I really didn't check. It was the original engine with a little over 78k on it, so I'm guessing Mazda put it together.