My driver side footwell gets very warm in the summer and I can feel that the added heat is coming from my Heatercore. Pretty sure I've seen where someone added a shutoff valve. (I'm thinking it was Externet but I could wrong)

My question is if anyone else has any experience with this mod and if it could cause any damage? I'm running a 180* inline thermostat that works very well, so I don't think it should effect engine temps much if any if I shut off flow.

Please share any experience or tips. My rover is black and spends a ton of time baking in direct sunlight so I'm really wanting to get this figured out.

 

I have a vacum bypass valve that I still need to install. Still playing with the setup. You will get 2 responses on this. One don't do it, and two go for it. It is said that leaving it alone helps with entire cooling system. Others have bypassed and have not mentioned any problems. My plan is to bypass during summer and activate in winter.

My planned setup Something similar to this:
http://www.summitracing.com/parts/fs...FUYA7AodhAsAgw

 

Hi.
The one I installed is here ----> http://i588.photobucket.com/albums/s...t/P1000960.jpg
Given me zero problems.

 

i did shut offs after i saw that ^ just to save on bleeding when I do some work. I have accidently driven with it turned off for a few days......no noticeable change in temps, but ambient was in the 80's.

 

This mod makes me nervous because I don't want coolant (especially dexcool) sitting in my heater core for months. I'm concerned it will lead to clogging or failure, especially if the system isn't perfectly bled.

 

I didn't know they made such a part. Thanks for posting that Ralphobell. I will probably order one later this week.

I run all green Mordo. Both discos came with dexcool and I've replaced both radiators due to sludge build up, so I won't be going back that route.

 

I put in a manual bypass valve last year and it works fine. No real impact on engine coolant temparatures. I can drive around with the a/c off and actually get relatively cool outside air coming in through the vents. When I do turn on the a/c it cools more efficiently as it doesn't have to fight the thermal transfer from a hot heater core. Definitely an upgrade in my opinion. I also run a 180 soft spring thermostat.

 

FYI that part was just a reference. Not sure if it is the correct size. The one I purchased was not from there and I can not remember for what vehicle it was for.

 

It is common practice on the old Series II-III LR. I have one on my 68 IIa. Shutting off the heater core won't affect water flow between engine and radiator. On a system that is not good due to sludge build up, etc. it may raise temps though since the system is already struggling to cool itself.

 

if you look around you can also cable and 12vt heater control valves, this one looks like an easy fit comes in veering sizes this one is 5/8 inch.
HVAC Heater Control Valve Rear Front 4 Seasons 74627 | eBay