My 87 XJ6 has been sitting for some time now, 7 years now, with the exception of occasionally taking it out for a short spin. I have been focusing on finishing up the resto on my 73 Vette. Now I am going to focus back on the Jag.
The A/C didn't work even before it went into hibernation mode. But now the heater core is leaking. Getting coolant coming out of the drain tubes on either side of the transmission.
So, for now, I have temporarily bypassed the core by connecting the two heater core in/out hoses at the firewall under the bonnet/hood with a pipe nipple. My question being, can I drive the car this way without issues? The core will eventually get replaced along with completely going over and fixing the A/C system at the same time. I just don't want to do it immediately.
Thanks for any input.

 

Sounds OK to me; I don't see how anything bad could happen

Cheers
DD

 

I agree with Doug, BUT.

With the HOT coolant going direct TO the return line and flowing into the lower hose spigot AFTER the radiator has cooled things down by design, you run the risk of "pre heating" the coolant BEFORE it gets to the engine. This can give a rise in engine temps, based on how effficient the radiator etc is.

3 V12's people did down here ( I know different engine, but same system) did run hotter than "N". I plugged both lines of those cars, thats all I did, and all back to "N".

Under normal operating conditions the tap closes flow until its called for, then it flows thru the heater core and dissipates heat to the passengers, before returning to the radiator spigot somewhat cooler than it left the engine.

I am not bagging the idea, just my experience over a few years.

 

Yes, I see. Looping would "deprive' the cooling system of the heat transfer afforded by the heater matrix whether or not he fans were on increasing the transfer. I dunno.

Many a leaky heater core has been deleted by the loop the hose method. I'm not aware of any issues.

Thinking that the heater hoses are far smaller than the radiator hoses. another i dunno.

Now, my car is a bit different and plumbed differently, i think. Reverse flow.
I installed a manul valve on the hose that does not have the vacumn operated valve. My idea was to eliminate any coolant flow to the heater matrix in summer. Therefore, i can run the fan and get power ventilation of coolish air. Not bad when AC is overkill.
I call that valve my summer/winter valve.

Older critters did something like that in pre AC days.

Carl