I plugged both ends with stainless steel Allen bolts, secured with clamps. I a have been running in this configuration for 2 years and roughly 15k miles from freezing cold in winter to 100 degrees Fahrenheit in summer and haven't noticed a difference nor any disadvantage.

 

Lots of other things are going to be critical at -12F besides the darn TBH Plate I can assure you. LR put way to much thought into it & then made the THOR setup just bloody awful. Millions upon millions of cars & trucks on the road today DO NOT even have a TBH Plate and they're all over the world in all kinds of weather daily with ZERO issues.

It might just be a 5/16 line, but it's being fed off the intake right behind the water pump. It's what I call a slow killer. It'll start off as a slow seep and if you're lucky you'll spot the famous crud Dexcool leaves behind when it seeps. If not most of it will drip down onto the hot exhaust manifold and burn off without even leaving a puddle under the LR. Then one day your coolant level will reach a critical low level and your worthless Temp gauge won't give you any clues until your engine has over-heated and it usually happens at a time you don't want a LR running hot like in the summer, out in the middle of nowhere, or when you're towing something and putting added stress on your LR.

That's when I decided to delete all the THOR TBH's I can get my hands on. I was once like oh I'll just get a replacement it's cheap, slap it on with a little RTV, then 3 months later see it seeping.... Only to replace it one more time with the same results. After strike 3 that was it for me. I even know several people that paid the $$$ for that brass unit only to be disappointed in either the quality of it or that it ended up leaking as well. Problem lies with the design with 3 bolts vs 4 bolts. It puts stress on the housing and the gasket and bingo when it expands and contracts it eventually starts to leak.

I re-route the intake line back to the reservoir for better flow just because I don't like 2 different lines eventually filling up with goo from no flow. I grew up wrenching on my dad's older 4x4's like his 77 CJ7 and his heater core was trashed so the heater hoses were just capped off. Well one day a 3/4 heater hose blew out and when we replaced it the goo inside both dead ends was nearly 6-8 long of just goo that collected there overtime. Also saw similar thing happen with my brothers 66 Series II 109 Safari Wagon. I'd rather have a nice flow going back to the reservoir vs 2 dead ends, but you do it the way you want, but deleting the THOR TBH has way more advantages vs disadvantages no doubt about it.

 

Has anyone put in a bypass valve to give the option of routing the coolant directly back, or to the TBH for really cold conditions?
I purchased a heavy duty TBH which I'm going to install, but 99% of the time it not going to be needed. It's not always winter in Wyoming or Montana.

 

just go to your local home depot or something and make your own with a bypass valve or shut off valve

 

Thanks for all the valuable input; this job is done! I found my throttle body heater hoses had visible cracking and were basically glued to the barbs so I just went ahead and removed the belt/ac compressor and ran the 5/16 transmission cooler hose from the coolant bottle to the barb at the top of the engine. I soaked the hose in hot water and applied a bit of dawn dish soap to the ends to help them slide over the barbs. I also used some 1200F heat sleeve that I had leftover from another project to protect the coolant hose run over the exhaust manifold.

 

The video you linked earlier showed that person having a lot of trouble getting the hose to go on the intake manifold outlet. How difficult was that for you, given that you were well educated about it, and soaked the hose and used Dawn?

 

I personally have had the throttle body freeze on our 2004. I was driving and everything ended up fine, had it been my wife or kids driving it would have likely ended up much differently.

If you are in a cold climate it's a bad idea to bypass...

 

What exactly happened?

I have mentioned in just about every single TBH thread that you can certainly have a TB plate stick if it's dirty enough as I personally have seen 2 act up several years ago during winter. They thought the TB froze up (both had the TBH plate bypassed), but it was actually the TB plate sticking due to grime on the very outer edge of the TB plate itself. It doesn't even have to be winter truthfully. D2's aren't getting any younger and I recommend fully cleaning the TB and the TB plate with a scotchbrite pad on the outer edge. It can look perfectly clean, but trust me cleaning the outer edge is a must. The other thing I see on almost every single THOR LR I've worked on = throttle cables and cruise control cables way out of adjustment due to the cables stretching over the life of the vehicle.

 

The 5/16" hose went on the barb at the coolant tank without issue as there is plenty of space to twist the hose. The barb on the top of the engine is more challenging since its physically larger and coolant is escaping but I was able to get it started by hand and then seat it with the help of my long needle nose pliers. If I had to do this job over I would drain a bit of coolant and cleanup the barb with an emory cloth to allow the hose to slide more easily.

 

This was about 10 years ago. The nipple for the return line on the reservoir broke off. I plugged it to get by and thought it wouldn’t be a big deal. It was a cold Minnesota day and we were traveling in the country with the cruise on. I tapped the brakes to kick off the cruise to make a corner and we didn’t slow down. I was able to smash the brakes and make the corner on what felt like two wheels. If we had been in traffic I would have rear ended anyone in front of us. At slower speeds it seemed to keep the under hood temps up enough to not have it happen again. After replacing the reservoir and repairing that circuit, we had no more issues. No cleaning or other maintenance/repair was made.

It was probably -20, but I just don’t see the benefit of bypassing it when there’s even a hint of it freezing.