If old antifreeze can do this kind of damage, I'll be changing it a lot more frequently: Was enjoying my new Aluminum radiator on the way to work one morning, then I began to smell something. A few minutes later, I was on the freeway with a bathroom faucet of antifreeze spraying my feet. Not good.
Uh oh.. I've seen this once or twice. The radiator starts to leak and once it's fixed the heater core pops. Next step is fixing the bad head gaskets!
Then the leaking rear main seal. Then out comes the engine completely and the "while we're there" syndrome kicks in and your car is stripped, on a rotisserie, off the road for 5 years and $40K later
Absolutely strip that car to bare bones for a full restore. Its only a few more bucks for engine, trans, rear end, interior, paint and body work, re-chrome bumpers, stainless exhaust
Fortunately, I was able to stop at the "engine comes out" stage of my own personal "while we're here" moment. Oh, you're way light at $40k.
This is why I started to go on any drives of more then 15 miles with a long enough lenght of heater hose in the trunk to jump out the heater core!
I was being serious. Check to see if it's building excessive pressure. You might be finding the weakest link as you go.
Looks are not deceiving. I replaced this core, myself, ten years ago after I got the vehicle back from the body shop after 18 months. The water pump had been replaced earlier, and the radiator is brand-new.
Ya when I replaced mine I went to a local rad shop and he checked out the brass one I bought then pressure tested it. He said it was good but then told me he had a bunch of old 1960's/70's stuff in his shop attic. He wouldnt go up for a core for me.
Then why bother telling you? I'm lucky enough to have the only radiator shop in a 40 mile radius 5 minutes from my house. He's done 3 Harrison radiators and 3 heater cores in the last couple years. A couple of those were for board members on the other coast, too. Good radiator guys are a dying breed.
"Garantia..." Mexico. Got it from CARS....the one going in is also a Mexico re-pro from CARS. Never seen the tank crack like that. I thought it was the seams or the core tubes which were more prone to leak, not a crack in the middle of the tank.
Uh Oh... my rear main seal is leaking and Ray said to bring it up in the spring, put the motor, install the seal, hone the engine, new rings, gaskets, oil pump, timing chain and gears... I can see this getting out of control....really fast. The good part, I have all the parts I mentioned already, except the seal.
Heater core & Radiator are made of soft metals, i.e. brass/copper. Head gaskets are made of steel = hard metal & less prone to corrosion & leaking. There's 20+ years on my engine blueprinting job, still runs great & the new radiator had it running nice & cool for almost 2 weeks until the heater core gave out on me while going 70 MPH on the freeway.
I'm not sure what your point is. Lots of steel head gaskets have failed long before radiators and heater cores.. All i'm saying is you just replaced your rad and shortly thereafter the heater core pops. Looking at the failure the heater core burst. It's not excessively corroded or thin looking from the pic. Looks like it burst to me. I've seen this before, you ought to have the coolant checked for hydrocarbons. It doesn't have to be a massive leak to cause problems. Why did you replace the rad?
Is there a restrictor in the heater-core supply plumbing? VERY easy to pop a heater core if there's no restriction in the supply plumbing. Water pump pressure adds to radiator cap pressure, the heater core gets over-pressurized. My Chevy pickups have the heater-core supply choked down to about a 1/4" passage via the quick-connect screwed into the intake manifold. Olds and Pontiac had restrictors on the heater supply, too. I bet Buick is supposed to have one; the original restricted fitting corrodes, and gets replaced with generic pipe-thread pieces that aren't restricted.