Is there a bypass on the heater core - 1997 Oldsmobile Achieva

not sure if this is what you are after but try this link..
Step 3: Connect the Hoses Together. Use a hose connector or hose coupler to attach the two ends of hose together. That way, the anti-freeze that would be routed through theheater core will instead just go through a short loop of tubing.

How to Bypass a Car Heater Core ' DoItYourself.com

www.doityourself.com/stry/how-to-bypass-a-car-heater-core How can bypass the heater core Google Search

These cars are notorious for having blocked heater cores, causing the heater to blow cold air. That's because there is a heater core bypass hose near the firewall that allows the coolant to bypass the heater core. Eventually the heater core fills with gunk and no coolant passes through it. You'll need to disconnect the hoses from the heater core at the firewall and flush the core using a garden hose. Flush both ways till water runs clear. If you can't access the heater core fittings at the firewall, then follow the hoses from these fittings back to the engine and disconnect them at that point and flush from there. If you flush from the hoses in this manner, it is important that you clamp off the bypass hose at the firewall with a vice grip pliers.
Otherwise the flushing water will go through the bypass hose and not the heater core.

No. You eventually will need the heat to defrost and de ice the windshield though.

to by pass a heater core just connect the two hoses to the heater core together with a connector and hose clamps.

This is a very common problem on the Taurus, at least up until the 2001 model and possibly later. The Taurus design incorporates a bypass hose (near the firewall) that connects between the heater hoses entering and exiting the firewall in the engine compartment. As the Taurus ages (6 or 7 years old), the heater core under the dash increasingly gets clogged with gunk because the bypass hose provides a path for the coolant to bypass the heater core itself. The fix is to disconnect the heater hoses at the engine block (too difficult to disconnect these hoses at the firewall-no space) and flush the heater core through these hoses with a garden hose. Before doing this you must crimp (with vise grips and a rag to protect the rubber hose) the bypass hose--otherwise the flushing water will bypass the heater core. I attached the garden hose to an adapter that I could clamp into the heater hose to make the connection. BTW, the coolant in the radiator was a pristine lime green color -notice the dark brown color of the gunk flushed from the heater core.

More than likely since your heater core is by-passed,your thermostat was probaly removed and you may be without one.Here's a link to check and replace it.Here's a link to heater core.Your heater core could be bad since it was bypassed,does the front floor board have water stains anywhere.

For heater core replacing procedure. I suggest you to go through this related help links.Its all complete step by step procedure: ----How to replace heater core for All car models?

Click the link below: ---

http://technoanswers.blogspot.com/2011/11/how-to-replace-heater-core-for-all-car.html

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How to Flush Heater Core?

http://schematicsdiagram.blogspot.com/2011/12/how-to-flush-heater-core.html

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How to Remove Heater Core ?

http://howtobyme.blogspot.com/2011/12/how-to-remove-heater-core-on-2008-honda.html
Heater Core Replacement?

http://howtobyme.blogspot.com/2011/12/honda-heater-core-replacement.html

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To replace heater core?http://technoanswers.blogspot.in/2012/02/how-to-replace-heater-core-on.html------

How to replace heater core?http://technoanswers.blogspot.in/2012/02/how-to-replace-heater-core-on_10.html
How to replace heater core on Buick Regal?

http://howtobyme.blogspot.in/2012/02/how-to-replace-heater-core-on-buick.html
----------This will help.Thanks.

You should be able to look down in between the motor and the firewall and see if the heater hoses are attached to the heater core. Most of the time when they are bypassed it is because the heater core has started to leak. Instead of replacing the heater core (not a fun or easy job) they just bypass it so they won't leak coolant. So, if it is bypassed your probably looking at replacing the heater core in order to get heat.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Too much blockage in heater hoses or heater core.
Bypass valve may be stuck on "bypass" .

1. Remove bypass "Tees", but don't discard.
Replace with straight-through hose fittings.
The core may start leaking under the water pressure since there is no bypass hose.

Once the heater starts working, put Tees back in place. You need bypass protection or the engine will overheat.

yes u can bypass the **** core. all you need to do is, take the two hoses going to the heater core, and take em off the heater core, take one hose comply off, and hook the other remaining hose were the other hose was hooked up at.. this will bypass your heater core, but keep in mind you will not have hot air in the cabin of the car..keith...