janarvae

'91 L98. I see mist coming out of the air vents. The flow of mist increases with engine speed. I also see some drops of liquid on the passenger side footwell. Car almost overheated today in the Florida heat (~85*). Intake gaskets and thermostat replaced, coolant recently flushed well and system burped. No visible leaks, except inside the passenger compartment.

The droplets and mist point me to the heater core. I'm thinking of bypassing it until I have the time to install a new one.

I know the older models had a door/flap that sometimes malfunctioned. Will removing the heater core affect temperature control?

Can a bad, leaking or clogged heater core cause overheating? I'll check coolant level as soon as it cools down enough.

Thanks,

Jonathan

floridamale

I also live in Florida my heater is by-passed car runs fine. Heater Core = Corvette Part # 00001 car was built around it

janarvae

Thanks for the input. From reading the experience of others, I'll have to dedicate an entire weekend to it. I can't this weekend though.

Do you know if a bad heater core can cause overheating? And if the symptoms I mentioned above point to a failing heater core?

Thanks,

-Jonathan

engle1147

If you had/have a busted heater core the engine coolant will escape while running and air can enter the block once the engine is shut off creating air pockets on the next run cycle...at this point it can cause overheating issues. My heater core is bypassed as well....I have no over heating issues currently. Just pick up 2 90 degree elbows and a short piece of heater hose to connect the loop...oh and 4 clamps. Fix the heater core when you have the time for an all day event....and when your done you can come up here to Tampa and fix my busted core too

floridamale

If you come to fix mine I'll buy beer and fire up the grill

janarvae

Sounds good guys.

I picked up a 3/4" to 5/8" hose adapter and some 3/4" heater hose. I'll remove the upper 3/4" hose that goes from the surge tank to the heater core. Then I'll attach that to the 5/8" heater hose coming from the water pump. The TB is already bypassed, so it'll be a straight shot from the water pump to the surge tank.

It looks like the 90-96 heater cores are much easier to replace than the 84-89s. I'd be willing to give a hand though when needed.

Thanks,

Jonathan

MrNuke

Not by a longshot. I've had to replace the heater cores in my '85 aswell as my '92. F'ing PITA on both counts. (Unless you're Gumby and can bend in really odd shapes)

Although on the '92 I bypassed it until the winter , then did it in the garage nice and slow.

floridamale

I can do mine it’s just I don’t feel like spending 4 hours being a contortionist. That and living in South Florida how cold dose it get right