3800 - No Heat When Thermostat Installed (Page 2/2)
Matthew_Fiero AUG 14, 08:46 AM
Has anyone set up their 3800 swap using a modified Fiero thermostat bracket? If so where did you connect your heater core lines to?

Thank you,
Matthew
fierosound AUG 14, 11:40 AM
Port circled in red is the suction side of the water pump.
Your heater return hose should connect there.
Matthew_Fiero AUG 14, 01:42 PM

quote
Originally posted by fierosound:

Port circled in red is the suction side of the water pump.
Your heater return hose should connect there.




And instead move the cap to the port under the LIM?
olejoedad AUG 15, 07:50 AM
Matthew, both of the ports you are using for your heater core hoses are pressurized.

The port on the front cover should be used for the heater core return line, and the port below the snout should be plugged.
Matthew_Fiero AUG 15, 09:12 AM

quote
Originally posted by olejoedad:

Matthew, both of the ports you are using for your heater core hoses are pressurized.

The port on the front cover should be used for the heater core return line, and the port below the snout should be plugged.



Thank you. This is the way I had it when I first built the engine. I'll switch it back and report back. My hose is too short now to reach back to the timing cover so I'll have to go purchase another length first.

Thank you again for everyone's input!

Matthew
Spoon AUG 15, 07:14 PM
There is also Plan "C" for the 3800sc. Use the modified Fiero t-stat housing to send water to the heater like you're doing. Dump the heater return water into the passenger side coolant pipe near the rear pass-side wheel well like the 88's. All you need is a Tee in the rubber inlet hose to the water pumps suction side. Less hose clutter at the engine too. Plug the port on the water pump with freeze plug or tap threads and plug it. Same with the one on the manifold. See pics'.












I did mine this way and I have plenty of heat. The last 2 images are respectfully borrowed.

Spoon

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"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

[This message has been edited by Spoon (edited 08-15-2021).]