looping coolant lines together

[Triathletedave]

I think I know the answer, but can anyone confirm if these two pictures both represent the same two cooling lines that need to be looped together at the back of the engine? The short connector in the first picture is recommended to be replaced with a 'fill tube'? What purpose does this serve?

fill tube1.JPG

fill tube2.JPG

[wallace18]

That is so someone can flush out the cooling system. An aftermarket part. You can leave it or get rid of it. Those are the correct lines.

[AZPete]

Those coolant tubes feed the heater core in the donor, don't they? Can someone please tell me which is the outlet that goes to the heater core?

[Triathletedave]

Thanks! This is as I suspected. I'll consider putting that in at some point after the car is finished. Certainly no need to rush on installing a flush valve now.

[ruckus racing]

Fill tube not needed. Just maks sure what you are using isnt kinked. There are 180º bend silicone hoses. I have 2 in my spare parts collection

[Wayne Presley]

Those coolant tubes feed the heater core in the donor, don't they? Can someone please tell me which is the outlet that goes to the heater core?

The one coming from the coolant log on the top of the motor goes to the heater. The one that goes to the waterpump/thermostat housing is the return.

I think I know the answer, but can anyone confirm if these two pictures both represent the same two cooling lines that need to be looped together at the back of the engine? The short connector in the first picture is recommended to be replaced with a 'fill tube'? What purpose does this serve?

fill tube1.JPG

You must loop these or your thermostat will never open.

[Triathletedave]

You must loop these or your thermostat will never open.

Thanks Wayne. I understand the need for the loop, but I was questioning why it should be 'replaced' with the fill kit attachment instead of just having the simple loop. It just seemed like a very odd location for a fill attachment.

Cheers,

Dave

[AZPete]

Wayne, you wrote, "The one coming from the coolant log on the top of the motor goes to the heater. The one that goes to the waterpump/thermostat housing is the return." I can't follow these tubes to see where they go among all the stuff on the engine.

I've searched my photos from when I was cleaning the engine and found this one that shows to 2 tubes at the top of the engine. If that's the "coolant log" then the top tube goes to the heater, right? And, does this black tube (bottom tube) go to the water pump/thermostat housing? I want to be sure so I don't screw up the cooling system as I plumb the heater core. Thanks!
engine top 2.jpg

[Wayne Presley]

Wayne, you wrote, "The one coming from the coolant log on the top of the motor goes to the heater. The one that goes to the waterpump/thermostat housing is the return." I can't follow these tubes to see where they go among all the stuff on the engine.

I've searched my photos from when I was cleaning the engine and found this one that shows to 2 tubes at the top of the engine. If that's the "coolant log" then the top tube goes to the heater, right? And, does this black tube (bottom tube) go to the water pump/thermostat housing? I want to be sure so I don't screw up the cooling system as I plumb the heater core. Thanks!
engine top 2.jpg

Your photo is correct. Make sure you have a constant flow through the heater and your heat unit doesn't turn vary the water flow to control the heat. If it has a water valve then you will have to get a shuttle valve so total water flow stays constant, the valve varies how much water goes to the core and how much gets run to the motor.

[AZPete]

Thanks Wayne. I tried to find the answer in the factory service manual before bothering you but I couldn't find it. I understand about the heater valve and keeping some flow. Actually I'm connecting to a heater core in a Vintage Air mini unit that fits nicely under the dash. Here in the AZ desert A/C adds 4 months to the fun. Thanks!

BTW, a friend stopped by to see my build and he admired the K-Tuned shifter more than all the nice work I've done. Next time I'll cover it up!

[Wayne Presley]

BTW, a friend stopped by to see my build and he admired the K-Tuned shifter more than all the nice work I've done. Next time I'll cover it up!

It really is the coolest part to add to an 818

[JeromeS13]

Not sure it's been mentioned, but be VERY careful not to confuse the two caps. The one on the upper reservoir vents under pressure and draws a return on vacuum. The OEM cap on the radiator only opens under pressure.

[Bob_n_Cincy]

Not sure it's been mentioned, but be VERY careful not to confuse the two caps. The one on the upper reservoir vents under pressure and draws a return on vacuum. The OEM cap on the radiator only opens under pressure.

Subaru fixed that on the forester so you couldn't mix up the radiator caps. They didn't put one on the radiator.

47775437.jpg

Notice that there is an air bleed hose from the top passenger side of the radiator to the "Engine coolant filler tank" (degas tank) Wayne's hose take cares of that getting the air out of the top of the engine.

Bob

[FFRSpec72]

OK, I went to do this over the weekend and I don't have these 2 lines, I only have one line, the engine is a JDM EJ207v7, anyone else have this issue?

Here is a picture and you can see just the one line coming out near the starter area.

WP_20140316_002.jpg

[Bob_n_Cincy]

OK, I went to do this over the weekend and I don't have these 2 lines, I only have one line, the engine is a JDM EJ207v7, anyone else have this issue?

Here is a picture and you can see just the one line coming out near the starter area.

WP_20140316_002.jpg

Hi Tony
The pipe by the starter is hot feed to the heater.
My engine has a second tube that returns water to the bottom driver side port of the water pump.

water pump.jpg

I suspect your engine has a hose that goes there directly.
Bob

[FFRSpec72]

Hi Tony
The pipe by the starter is hot feed to the heater.
My engine has a second tube that returns water to the bottom driver side port of the water pump.

water pump.jpg

I suspect your engine has a hose that goes there directly.
Bob

So still not sure what to do but i will chase down where the bottom hose on the water pump goes.

[Bob_n_Cincy]

Tony,
That hose is very important. It brings hot water to the engine side of the thermostat to control opening and closing.
Bob

[GUNS]

FWIW, the 02 wrx doesn't look like the picture in the manual. Here's what I looped together (follow the line w/ the blue tape):

[FFRSpec72]

Thanks, so it looks like its these 2 lines that I have circled

HeaterLines-1.jpg

[GUNS]

Yup! Disclaimer: I haven't found any of this in writing however, I did label these when disassembling the donor and it's the only two lines that make sense. Also, car seems to run just fine .

[gwarden]

Subaru fixed that on the forester so you couldn't mix up the radiator caps. They didn't put one on the radiator.

47775437.jpg

Notice that there is an air bleed hose from the top passenger side of the radiator to the "Engine coolant filler tank" (degas tank) Wayne's hose take cares of that getting the air out of the top of the engine.

Bob

I've read something about Wayne recommending a hose to help purge air from the system but can't find that post
Can anyone help me find it?

[wallace18]

I've read something about Wayne recommending a hose to help purge air from the system but can't find that post
Can anyone help me find it?

http://thefactoryfiveforum.com/showt...ooling-burping

Here is one reference I also show it in my build thread.

[gwarden]

The one coming from the coolant log on the top of the motor goes to the heater. The one that goes to the waterpump/thermostat housing is the return.


You must loop these or your thermostat will never open.

I have an 02 wrx with the heater lines spread wider apart. it also had smaller lines going to the throttle body that I eliminated and looped over this is about a 1/4" line is it good enough for flow to make the thermostat work and can I just plug off the heater lines?

[Wayne Presley]

Not enough flow, you must loop them or your thermostat will never open

[Turn In Concepts]

As mentioned you definitely need to loop the lines. If you don't cylinders 2 and 4 will run hotter than 1 and 3 which is bad considering that 4 is the "hottest" cylinder in the motor in terms of ECU tuning.

Coolant flow for an older EJ turbo motor, but still more or less applies.

[Bob_n_Cincy]

Tony,
If you remove the oil warmer (under the oil filter) Can you just block off those lines or should you loop them?
Bob

[billjr212]

Along the same line as Bob's comment, any reason to not just block off the throttle body lines at the source t's rather than looping them together?

[gwarden]

I don't think looping the throttle body lines would be needed as long as you are looping the heater lines

[billjr212]

I ended up just going back to the sources and tying them together. It was such a short run and tucked away, so I figured why not.

[Turn In Concepts]

You can block off the throttle body lines and the oil warmer lines without issue. If you do it though don't just use rubber caps as they will fail. A 1/4 npt plug fits the water pump well. Pull out the spigot for the line and tap the hole for the 1/4" plug. No drilling of the hole required. On the other end get the large threaded cap off an engine that does not have the warmer to cap it off permanently.

Tony

[Mechie3]

I cut off the nipples for the throttle body feed and return lines and welded them shut. Put rubber caps on the nipples on the throttle body itself just to prevent dirt from getting in.

[FFRSpec72]

I cut off the nipples for the throttle body feed and return lines and welded them shut. Put rubber caps on the nipples on the throttle body itself just to prevent dirt from getting in.

So on my JDM the TB feed just connects to the 2 lines I looped, so why do the TB ?

[C.Plavan]

I bypassed the throttle body nipples, then just looped the two lines together. Then put rubber caps on the throttle body nipples.

I did that right, correct?

[Mechie3]

So on my JDM the TB feed just connects to the 2 lines I looped, so why do the TB ?

Not sure I wrote a good description. I welded shut the nipples on the aluminum crossover pipe and the steel coolant pipe under the manifold. You can just loop these together but, since my parts were off the car and easily accessible, it was a little bit cleaner to not have the loop. I bypass the TB so that I'm not heating it up.

[FFRSpec72]

Not sure I wrote a good description. I welded shut the nipples on the aluminum crossover pipe and the steel coolant pipe under the manifold. You can just loop these together but, since my parts were off the car and easily accessible, it was a little bit cleaner to not have the loop. I bypass the TB so that I'm not heating it up.

OK, understand, I will look at bypassing the TB also

[CU9DZ]

I have the 02 WRX donor with the heater lines about 12 in apart. How long of a hose do I need to loop them and what is the interior diameter? Also is there some pre bent hose from some car that fits?
Dave

[Wayne Presley]

I have the 02 WRX donor with the heater lines about 12 in apart. How long of a hose do I need to loop them and what is the interior diameter? Also is there some pre bent hose from some car that fits?
Dave

some 5/8" hose works fine

[metros]

I believe I used 16" of hose to get a decent shape to line without kinks. Get a little more and trim it to your liking.

[CU9DZ]

Great Thanks. Next time I go to parts store. Will get 16"+ of 5/8" hose.
Dave

[ben1272]

Thanks for all the input. I have same layout and glad to find all you contributions. Great community here!

-Ben