Bypass throttle body coolant hoses? (2016 KIA Forte)

MR 22

MR 22

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I thought about doing this cheap "mod", but I am curious. Has anyone here on BITOG ever done this to their vehicle before? Good idea, or a HORRIBLE, foolish one?
My car's Throttle Body has two coolant hoses running to it, SHOWN HERE.
I was thinking of this mod because:
  1. Removing the Throttle Body in the future will be easier so I can clean it.
  2. I've heard that coolant runs to the Throttle Body to keep it warm & prevent it from freezing/sticking. However, without coolant heating it up, the Throttle Body will stay cooler, and so might the air passing through it? (Maybe?)
Our Summers are VERY hot where I live (up to 115°F), but temps can occasionally go below freezing during Winter (as low as 28°F).
What does everyone think? I value your advice, Thank you.:) (I have not yet attempted this mod; seeking advice first.)
 
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I've did on a few but always put it back. Never any issues just leads to non factory coolant routing. And if you get that wrong and it comes loose rubs against the belt.. doesn't make a pleasant time on the side of the road.
 
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MR 22 said:
I thought about doing this cheap "mod", but I am curious. Has anyone here on BITOG ever done this to their vehicle before? Good idea, or a HORRIBLE, foolish one?
My car's Throttle Body has two coolant hoses running to it, SHOWN HERE.
I was thinking of this mod because:
  1. Removing the Throttle Body in the future will be easier so I can clean it.
  2. I've heard that coolant runs to the Throttle Body to keep it warm & prevent it from freezing/sticking. However, without coolant heating it up, the Throttle Body will stay cooler, and so might the air passing through it? (Maybe?)
Our Summers are VERY hot where I live (up to 115°F), but temps can occasionally go below freezing during Winter (as low as 28°F).
What does everyone think? I value your advice, Thank you.:) (I have not yet attempted this mod; seeking advice first.)
Click to expand...
It’s a great way in subzero weather to get ice buildup around the shaft and hang the throttle open. This was a cheater mod back in the 80s with the Mustang 5.0s. I’d call this a hard pass if you ever get below freezing.
 
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Yes, I bypassed it on my 02 Corvette. I drive it all year and I live in TX. No issues. I only drive it to CO in the summer though.
Its the blue hose.

DSCN7856.JPG
 
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It really won't make any measurable difference with regard to intake air temp. The heating is there to prevent icing. If it's a performance car, with other mods, sure why not maximize the situation and reduce the chance for coolant leaks. But in general, every day use, immeasurable.

Remember, it takes one heck of a lot of intercooler surface area to change the intake air temp significantly.
 
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Something leaked in there on my 1st '88 528e. That being the only place it could leak from, I deleted it with a hose barb.Not sure of anything,I bagged the pieces and stapled it to the shop wall in case I needed.it. That was around 2K, it's still where I put it :cool:
 
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I have done this on a few of my cars, but for a different reason. While I have not had any issues down to single digit temps, i'm not sure I would recommend it. My throttle body is literally an inch or two above the exhaust so that may be keeping it warm enough not to have issues. Pretty sure yours is no where near the exhaust. You would never feel any difference in actually keeping things cooler anyway.
 
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A few previous threads on this or a similar topic which may be of some interest:

Coolant Bypass

Will a coolant bypass filter using TP work? Will such fine filtration buy me anything compared to running a standard filter in the coolant system?
bobistheoilguy.com

Why are IAC Valves Heated?

Why are modern computer controlled IAC valves heated with coolant? From what I have read, it appears coolant is there to prevent freezing. However, many believe coolant warms the IAC and controls operation. I think that used to be true with older designs where IAC valves had bimetallic springs...
bobistheoilguy.com

Intake air regulated at 131°F / 55 °C !

...this is according to the factory manual. Until last summer I was zooming about with sensor calibrated about 100 °F / 37 °C. Then I discovered this on the service manual and re-adjusted it accordingly to see what happens. Specs are very detailed like, heat door should crack open @ 100 °F...
bobistheoilguy.com
 
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MR 22 said:
I thought about doing this cheap "mod", but I am curious. Has anyone here on BITOG ever done this to their vehicle before? Good idea, or a HORRIBLE, foolish one?
My car's Throttle Body has two coolant hoses running to it, SHOWN HERE.
I was thinking of this mod because:
  1. Removing the Throttle Body in the future will be easier so I can clean it.
  2. I've heard that coolant runs to the Throttle Body to keep it warm & prevent it from freezing/sticking. However, without coolant heating it up, the Throttle Body will stay cooler, and so might the air passing through it? (Maybe?)
Our Summers are VERY hot where I live (up to 115°F), but temps can occasionally go below freezing during Winter (as low as 28°F).
What does everyone think? I value your advice, Thank you.:) (I have not yet attempted this mod; seeking advice first.)
Click to expand...
It does not have to be winter or freezing temps for carb/throttle body icing to occur, humidity even a warmer temps can cause this.
I remember heat stove pipes connected from the air cleaner to the exhaust manifold shield with a hose to help prevent icing, coolant running through the throttle body will not heat the incoming air any significant degree but will prevent icing in the throttle plate area.
Bottom line, leave it alone. To make removing the throttle body easier with less mess clamp off the small coolant lines with pinchers like this before removing them.

hose pincher.jpg


 
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On my Gen Coupe turbo I bypassed them. On my Accent I did but as I use it mainly in the winter and when it's below 0F then it really hurts the furl economy. The IAT will run maybe 40F higher with the hose on than ambient. I was freaking out watching below 0F IATs! So it went back like it should. Thought about using an inline valve to shut it off in the summer but seldom drive it then anymore.

The Gen Coupe turbo I switched the IAT sensor to a fast acting one. With the OE that is encased in a plastic it will not see much temp drop at a WOT pull even with a huge intercooler. About 1-2F is all it reacts to when the actual change is 10-30F depending on ambient temps. The IAT normally runs around 20F over ambient with no heater hoses connected.

The time that you will see freezing is when pre throttle body temps are just above freezing and the throttle plate is mostly closed. The rapid pressure drop behind the throttle plate at partial throttle will drop the temp and if enough humidity cause ice. Not so much the problem if the air is way below freeing already .
 
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SHOZ said:
The time that you will see freezing is when pre throttle body temps are just above freezing and the throttle plate is mostly closed. The rapid pressure drop behind the throttle plate at partial throttle will drop the temp and if enough humidity cause ice. Not so much the problem if the air is way below freeing already .
Click to expand...
+2

I'll never understand the science, but it's something to do with the velocity and pressure and humidity.

I've mentioned it many times before, but I used to be involved with pile-driving operations, which use a large air compressor to power the hammer. In operation, the air outlet on the hammer would get a heavy coating of frost on it from the exiting air. This happened even in summertime 95-degree heat. Everything is baking in the sun and is too hot to touch; the hammer, the hose etc and even the air is hot. But it still managed to create frost which eventually would build up and break off as chunks of ice.
 
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PF52 said:
+2

I'll never understand the science, but it's something to do with the velocity and pressure and humidity.

I've mentioned it many times before, but I used to be involved with pile-driving operations, which use a large air compressor to power the hammer. In operation, the air outlet on the hammer would get a heavy coating of frost on it from the exiting air. This happened even in summertime 95-degree heat. Everything is baking in the sun and is too hot to touch; the hammer, the hose etc and even the air is hot. But it still managed to create frost which eventually would build up and break off as chunks of ice.
Click to expand...
Really high flow and a huge pressure drop. What is the line pressure PSI running at and the volume that suddenly goes to atmospheric. We had electrical cabinet coolers that were just air nozzles with a restriction. Then they decided compressed air was too costly which it is.

The opposite happens when you pressurize. Just like a turbo pressurizes the air and raises the temp.
 
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bdcardinal said:
Ford has a couple throttle bodies where the replacement number deletes the coolant hoses. They supposedly come with instructions on how to loop the system.
Click to expand...
In a similar vein, GM had a part number for a very short, little curved hose which was designed to skip the TB coolant heater connections. I'm not sure how many models it fit on.
 
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Every car that has had these I have bypassed over the years. The Accent is the only one I keep it on as it's such a cold blooded engine anyway.

I had a TR7 with twin side draft Strombergs on it. It had the heated air from the exhaust manifold paper tube thing. I had this bypassed too of course. One day when really foggy and cold as I was going to work the car started slowly loosing speed and pressing on the gas did nothing. I was down to 30 mph and finally pulled over. Found the throttle sliders were froze in position. But just sitting idling for few minutes thawed them out.
 
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Sorry for the long delay. I found the coolant hoses for the throttle body are in an extremely tight area which would require further, more complex disassembly to reach them.
Also, some of you mentioned it won't make much of a difference but it will increase chances of freezing.
I decided it's my best interest to leave it alone, and so I did. Thank you again everyone for your advice. (y)
 
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