Just got the car on the road today. Drove about 40kms mix of city hwy.
Car runs great except a puff of something from under the hood and can't find any leaks. This is possible causes.

Heater core has gone bad it's bypassed for now and connections (line in and out coupler and hose clamps)seem to be holding.

I did a brake job last fall and decided to see how the car slows under heavy breaking. Stops great (prop spring with new fluid and pads).
Just after braking I noticed a large puff and looked like something a blown rad or coolant line would produce. I shut the car off with in seconds. Wondering if my heater core flanges would have some old coolant still splashing around and while under hard braking cause the resudual coolant to move forward towards the headers.


So hard exceleration followed by hard braking puff of something???

-Valve covers were not very tight
-breather could spit out oil?
-I've checked brake lines but everything seems tight with no leaks under the car or sitting in the engine bay

Thoughts ?

 

Almost positive it was the old heater core splashing around. Let her buck!