ping damage or ??

[luket]

hey all, first post, and an embarrassing one, so go easy on me

got a 79 spider 2000 about 6 months ago for a commuter and doing some casual restoration work while i enjoy the breeze.

I adjusted my timing about 3 months ago to best idle minus a couple degrees as i couldn't find a good angle to view the tick mark on the fly wheel. One of the first warm day of spring i had it out and noticed a slight ping when shifting gear and climbing a hill. it being very occasional on warm days and me being a procrastinator i left retarding the timing on the to-do list. Now in august, the subtle ping continues but i might hear once a day for a second or two per drive under the same loaded conditions. The other day coming home from work on a warm day i noticed it was running rough had lost maybe 20% of its power, also the ping had become much more consistent and audible, at this time the thermostat, which works great, read the normal 190. This being a noticable change, decided i would go right home and poke around. on the last stop sign before my house, my heater core ruptures and a coolant waterfall soaks my floorboards. I gun it once and kill the engine for a stealth glide into my driveway a quarter mile down the road.

I pulled out the heater core and bypassed the system, checked with a bowl of hot water to find that the thermostat was seized. Also, my radiator fan may not have been working this whole time, (relatively new car, still finding surprises)

So ive got a new thermostat on order, but in the meantime, ive pulled out the goodies inside the old one so it would flow freely and i can check the engine. The loss of power is still there and the more audible and consistent ping as well.

so im trying to figure out if the loss of power is due to my bad procrastination and damage from the ping, or damage due to overheating, and whether these are isolated occurrences or if the overheat caused the ping which caused the damage, or if the ping caused the overheat which caused more ping causing damage etc, you get the point. The ping is just coming to mind tonight and i havent even pulled the plugs yet, but that'll be my first move tomorrow.

Any thoughts?

[131]

Something to start with:
What's it like at idle? Is it carbed or injected? In head or external thermostat? seized open or closed?

[luket]

carbed, in head, seized closed. Previously idled more or less smooth, with the occasional hickup. now it idles lower with a constant vibration like on of the pistons is firing poorly

[So Cal Mark]

the pinging could have destroyed the head gasket or a piston

[azruss]

you may be jumping to conclusions thinking the 2 are related. make sure the dizzy isnt loose, you are firing on all 4, vaccuum hoses are good and connected. how do your plugs look.

[luket]

idling a bit better with new plugs and firmed up the wires but the pinging still bad. Found a leak in the intake manifold which i think ties the overheat to the pinging.