WonkoTheSane

iTrader: (2)

Blah. Due to the overheating problems I am constantly having on my 86 NA, with 6400 on the rebuild, I'm going to tear it apart to see what happened. I'm pretty sure it has to be a blown coolant seal or something at this point.. My question is this: What is EVERY sympom of coolant seal failure?

Here's what I DON'T have: White smoke (ever. None on startup or running or high RPMS), My Coolant DOES NOT bubble at all, ever. There is no water in the oil at all.

Here's what I DO have: Overheating and dumping all coolant into the overflow (on runs over 10 minutes), a new (used) radiator, water pump, thermostat, radiator fill cap, new (used) fan, belts, hoses. Poor idle (just started happening, i'm not sure if it's related to this or something else), good oil pressure, factory fan shoud on, lower belly pan off.

Can/should I get this thing pressure tested before I overhaul, and will that reveal if somehow the water passages are blocked or something? I'm at the end of my rope here.. I have NO idea what is causing this problem AT ALL. HELP!

Amur_

A pressure test will only tell you if you have a leak. Here's a description, plus a way to DIY:
http://home.insightbb.com/~mmartin36/Pressure.htm


Is the thermostat aftermarket or Mazda? Aftermarket thermos have a BAD reputation around here...


Forget that last question. I just found your thread:
https://www.rx7club.com/showthread.p...rheat+overflow


Have you had your timing checked? Some have suggested that out-of-adjustment timing will result in overheating...

Other than that, not sure what to tell you...

WAYNE88N/A

Did you intentionally block any passages in the housings when you did the porting job during the rebuild?

I couldn't believe how freakin small those "in & out" passages were in that front rotor housing (from & to the water pump) when I was putting mine back together...

WonkoTheSane

iTrader: (2)

nice way to do it yourself I think i'm going to have a professional leak down test done, since I don't want to rebuild my engine again so soon. To answer your last question, yes, I own a timing light, and it's pretty much dead on (advanced slightly, nothing major). . Thanks for the input, though

edit : sorry Wayne, didn't see your post before I posted mine. no, I didn't block anything when i was rebuilding it. I had no problems with my engine for about the first 5000 miles after the rebuild. One day (about 1000 miles ago), it just overheated, and it's been getting more frequent after that.