Hey there..Happy Holidays!
New member here.. I have my dad's 1993 Buick Park Ave, that I picked up 4 years ago, after he died, as a daily driver---Had 129K miles then and has 151K now... Haven't had to do a thing except tires/brakes-- until NOW --> Heater core needs replacement. Have done it on other cars--GM's-- and have NOT had to remove the dash. On this one, Im not so sure However, neither Chilton, nor Haynes, has any detailed step by step instruction other than what to do inside the engine bay and in front of the firewall. And I cannot find ANY YouTube video that is about this generation Park Ave OR Lesabre.-- None. Not even a "cousin" Olds 98 or Pontiac Bonneville.
Some online diagrams don't show much about how to get TO the heater core, but only after you've gotten to it.

Any mechanics that may know, or be able to provide step by step help, or a link to a shop manual or some sort of guide----Much Appreciated!
The damn core was only $30, and I've by passed it so there is no leaking--but even here in Cali it's getting cold. Wouldn't mind some heat at 6am on way to work!

Thanks in advance for any help!

 

For starters this is an old high mileage car, nothing wrong with that but not exactly in antique collectible car status. I'd try looking into similiar models from either Pontiac or Olds. Both extinct now but maybe the Pontiac Bonneville would be close enough other than cosmetics with a more complete install/remove set of directions?

Perhaps only a faulty hose connection? I'd of definitely tried some of today's radiator sealant products, absolutely nothing to lose here (make sure heater is up full blast).

GUNK today as example makes an excellent product for home oil burners leakage (i.e. Beckett/Burnham models). No, they don't have cracks unless frozen solid at some point. Rather plates connected together as the old steam radiators. With age they will seep between seams (even brand new) and quite an amount of water will be on the floor. A small container of sealant will stop all leaks within an hour, no blockage of passages whatsoever. Has to be in service, goes without saying?

So reconnect the heater hoses (if possible) and try some sealer, probably car is primed for radiator and gasket leaks by now anyhow. Again controls for full heat of coarse, the results may be a surprise?

My opinion only here, what I would do. Don't see any other answers lol. Forgot, do my own oil burner service work, it's over 30 years old now and runs like new still. Is a Shadow under oil line on absorb mat, not oil leak That section has the oil strainer and fittings, bleeder, messy area.

 

The concensus seems to be the dash has to be removed for heater core replacement, Pontiac Bonneville forums Heater core replacement on the '93 : 1992-1999 I'd seriously try adding two containers of radiator sealant not just one, before tearing dash out......