sounds like the cooling system is completely plugged up, if there are "clumps" of sealant floating around the waterpump area, it'* plugging up the thermostat, radiator fins too, the floating clumps would prevent anything going through the thermostat

The system needs sucked/flushed out, many times, replace radiator, heater core, hoses
You will need 4 jugs of flush and run it for several hours to clean the block out

sounds like severe cooling system flush needed and replace all parts.hoses/elbos/rad/heater core/ and correct water pump

sounds like it has electrical issues too

How many miles?

160200 exactly. Also, according to the PO, all of the top end gaskets had been changed on recall or something like that. Also he said that the trans had been rebuilt within the last few years. BUT he didn't have any paperwork to prove any of it. I'm always wary of that kind of info.

I still haven't gotten it put back together. Between work and the heat outside, it'* hard to find the motivation.

The possibility for a blown head gasket still exists, but it may not present itself until the engine is warm. I'll try the combustion gas / block test as soon as I get it back together. If that comes back negative for a blown head as well, I'll flush the system. I just got a Lisle funnel setup and a flush kit (but I've got to figure out where to tie in the garden hose junction.

We'll see.

Is been awhile since I've been on here. I needed a brake from working on the van and there were things I wanted to finish on my TBird.

Anyway, I changed the plugs and wires, got it all back together and was going do an engine block / compression gas test but as soon as I started it up, it ran real rough. Hadn't done that before. Sounded like it was missing on half the cylinders. And the "service engine soon" light came on. Also got some snow from the front of the engine near cylinder 6. Probably got a little anti-seize on the head but it warrants a look.


Ran the OBD2 and got a P0300 code. General misfire. Haven't done much more yet. I checked the wires to make sure I didn't wire it backwards or mix up a couple of them but that looks fine.
Maybe I got an air leak near the MAF?

What else should I look for?

Also, (honest question) are all GM'* this hard to work on? Took me hours to change the plugs.

You would hate me if I told you how generous the engine bay is in the Park Avenue. From what I gather though, accessibility isn't the best in the 3.1/3.4, and being tucked in the Van under a portion of the fire wall too