Questions re coolant routing

Gypsy62 · **Posted:** Tue Jan 21, 2020 3:11 pm

I'm trying to wrap some coolant system mods:
1. If all heater settings are "Off", is there a bypass at the heater core or when "Off" is all coolant flow blocked between the two hoses feeding the core? Anybody happen to know which direction the coolant flows to/from the core [left/right hose @ firewall]?
I want to insert my [h2o-cooled Garrett BallBearing] turbo coolant-line into a heater-hose path. If there's a bypass at the heater core than there'd always be flow, if not I have to relocate the insert location.
Pic:

2. Thermo closed, which ports are DIRECTLY pressurized by the water pump? Thermo open?
I suspect the pump only directly "pushes" through the engine port and all others are "downstream", but maybe not.

3. Years since Sasq I&II, I can't recall where the coolant port is from the egr to the block on engine-left. Is this bolt the coolant plug? If not, what/where?

Anybody know the flow-direction?

4. Unrelated: anybody know if "Removable Front Headrests" was an OEM option for ANY '05 Liberty?

Many Thanks!

Keys: CRD coolant anti-freeze route routing system heater-core weeks 1 2 removable one-piece headrest

TKB4 · **Posted:** Wed Jan 22, 2020 11:49 am

don't know about coolant direction but there are 2 plugs on the driver side of head. I believe the one toward front of engine was where the crossover hose went to the Y on the passenger side that went to the heater lines IIRC. I will post a picture of the two plugs that are seen below the bolts in the glow plug holes. I can't tell which plug you are showing in the second pic.

TKB4 · **Posted:** Wed Jan 22, 2020 11:56 am

here is the pic of the two plugged area on driver side of the head.
https://imgur.com/cc4DsZf
The one on right is just in front of the number 4 cylinder glow plug and the one on left is just toward front of engine from cylinder 3 glow plug..

Mountainman · **Posted:** Wed Jan 22, 2020 12:50 pm

It flows out of the head to the egr cooler, otherwise it would be feeding exhaust-heated coolant to the head. I've thought about connecting both of those ports back around to where the original egr hose went for extra head cooling. You'd think it would keep the head temp more linear...?

WWDiesel · **Posted:** Wed Jan 22, 2020 3:55 pm

The flow from the port on the head simply flowed through the EGR cooler and then back to the water pump suction.
Flows/directions shown in this flow diagram:

Gypsy62 · **Posted:** Wed Jan 22, 2020 5:41 pm

You guys are friggin' awesome.
So:
1. Coolant flows constantly through heater core regardless of control settings. K.I.S.S: makes sense, less complicated.
2. Egr coolant plug identified.
-ish: shouldn't there only be one [supply] tap out of the block, given that the other line [originally] "Y" 's back inline near the thermo spaghetti?
3. Flow directions confirmed: water pump only "pushes" into its port feeding the block. All other lines & ports are downstream in the coolant loop.

I will still need to decide which side of the heater core is more advisable for the turbo's coolant line insert, but as long as there's constantly flow across both taps it probably doesn't much matter.

Re idea to restore the hose loop out of the plugged egr block-tap in order to reduce head temps... maybe, but I'm not sure truly necessary. As long as the other coolant system components are functioning properly the system should maintain correct, component-safe temps, no? I suppose it would permit engine-heated coolant to circulate out of the head more quickly.
The original routing through the egr could only have elevated the coolant temps looping back to the thermo housing, so good riddance.

On paper, I should be rolling within a few weeks (after 10 months down!). After, I'll post a thread detailing the turbo install, intake/exhaust mods, fan mods, provent mods, airlift install, tri-function gauge install, single-din pioneer dvd w/pop-up screen (& hitch-guide cam!) w/dual-amp 8-speaker upgrade, and uppity neoprene seat covers. Yeah, I've been messing with stuff since my original turbo started blowing last March...
I Advise Against Replicating My Misery!

Many, Many Thanks!

[KISS= KeepItSimpleStupid]

Mountainman · **Posted:** Wed Jan 22, 2020 7:01 pm

The forward plug is correct for the egr, and the aft one was used for the temp sensor in Europe on some models. I'm guessing either one would be a good point to supply turbo coolant or relocate the temp sensor if you wanted to. I think somebody on here (Flash?) Relocated their temp sensor there or added a secondary one in one of those ports.

Gypsy62 · **Posted:** Wed Jan 22, 2020 8:46 pm

Thanks, MM; very useful info!

Based on the outstanding coolant system component/flow diagram supplied by WW, I've decided to re-route the oil-cooler's coolant-out tap to the heater core "in" (right, at firewall) and keep my current setup (in pic above) with the h-core's "out" (left) feeding the turbo. I'll route the turbo's "out" to the tap at the pump housing liberated from the oil cooler's return hose.
It seems like that routing will preserve adequate coolant-volume and positive-flow: pump/block/oil cooler/heater core/turbo/pump.

The ONLY "easy" thing in this painfully-custom turbo install: astoundingly, the stock oil-supply line actually fits with this Garrett GT2560R mounted. I had to drill the tube's banjo fitting 1mm to accept the new banjo, and exert a mild modicum of tubular coercion, but it is IN. Upon ignition I shall be watching VERY carefully for leaks (with a cocked .357 in my mouth, argh).

Actually... no pistols to Mexico: = 10 years, or 50k bribe.

WWDiesel · **Posted:** Wed Jan 22, 2020 11:19 pm

Most like myself simply plugged the outlet coolant port on the head for the EGR cooler when removing and getting rid of the EGR cooler and all associated hoses and parts.
Replaced the "Y" fitting with a simple straight 5/8 barbed hose fitting.
Think about it, with the EGR coolant flow path operational and the engine up to normal temperature, you are dumping very hot coolant right out of the head (pre thermostat) right back into the water pump suction before it is pumped into the engine, head, and oil cooler for cooling purposes. That in itself would raise or increase the temperature of the coolant right after it has just passed through the radiator where it was cooled. Very counterproductive and very inefficient indeed not to mention bad on the water pump seals and bearings! :shock:

Mountainman · **Posted:** Thu Jan 23, 2020 12:48 am

This thread has me realizing why the factory ones stay warmer in the winter.

I'm impressed with your short span, simplified hose routing. I dont like running hoses all over the place, and loved removing the egr hoses.

Lol @ the bribe bit.

TURBO-DIESEL-FREAK · **Joined:** Sat Apr 17, 2010 3:29 pm **Posts:** 1167

Following along...

TKB4 · **Posted:** Thu Jan 23, 2020 9:11 am

Yes this has turned out to be much more interesting than I first thought it could possibly be! The coolant setup not the Turbo mod etc :pepper:

flash7210 · **Posted:** Thu Jan 23, 2020 10:00 am

When I did the egr delete I kept the outlet port in the head and routed it to the heater.
I cut the crossover tube shorter and the rest of the connections were as simple as clamping the hoses in place.
If you didn’t know better you probably wouldn’t notice the change.

Later I added a temperature probe to the head at the rear unused coolant port. Only the probe doesn’t actually go into the head. It’s just clamped to the threaded plug and pressed against the side of the head.
Not perfect but I just wanted to get an idea of what cylinder head temp was in relation to coolant temp.

flash7210 · **Posted:** Thu Jan 23, 2020 10:10 am

Quote:

I've decided to re-route the oil-cooler's coolant-out tap to the heater core "in"

Being that I recently replaced the engine oil cooler, I wouldn’t mess with it’s coolant hose.
The space there is really tight and you’re asking for a severe headache.

If you reroute the EGR cooler port to the heater, as described above, that will open up a port on the thermostat housing. You can now use that port on the thermostat for your “turbo cooler.”

Gypsy62 · **Posted:** Thu Jan 23, 2020 1:27 pm

In order to create adequate clearance for my big honkin' 3" turbo-intake elbow I had to modify both the pump and thermo taps: preserved the bypass hose using 2 90's in place of straight tubes, plugged 2 holes, inserted "T"s to preserve routing to/from remaining system components. Pics next week after road test.

30-seconds after ignition, the jeep will probably explode.

This routing symposium may be particularly helpful for those living in cold climes. Establishing the "hottest" tap to feed the heater core for accelerated cabin-warming? Or, maybe the temp variation between taps is only nominal and doesn't really matter.

Regardless, I'm choosing to feed the turbo post-core. A heater core is basically a little radiator, so in theory it 'should' knock-down the coolant temp upon exit. Excluding radiator-out, post-core should be the comparatively lowest coolant temp in the entire system, no?

I replaced the mech fan with a 3-fan setup; one large puller (activated by the gasser wiring's low/high) & 2 9" pushers (one tied to fan-high, one over trans cooler, both w/manual switches). Desert temps, towing, etc.
Testing with all 3 fans on "High", Dorothy & Toto were flying around the engine compartment...

The manually-controlled dance between optimum operating temps and excessive heat should prove entertaining. Maybe that idea of a 2nd temp sensor @ egr-tap is a good one... later.

Thanks again to all for piping-in with valuable info and insight.

WWDiesel · **Posted:** Thu Jan 23, 2020 1:55 pm

Gypsy62 wrote:

In order to create adequate clearance for my big honkin' 3" turbo-intake elbow I had to modify both the pump and thermo taps: preserved the bypass hose using 2 90's in place of straight tubes, plugged 2 holes, inserted "T"s to preserve routing to/from remaining system components. Pics next week after road test.
30-seconds after ignition, the jeep will probably explode.
This routing symposium may be particularly helpful for those living in cold climes. Establishing the "hottest" tap to feed the heater core for accelerated cabin-warming? Or, maybe the temp variation between taps is only nominal and doesn't really matter.
Regardless, I'm choosing to feed the turbo post-core. A heater core is basically a little radiator, so in theory it 'should' knock-down the coolant temp upon exit. Excluding radiator-out, post-core should be the comparatively lowest coolant temp in the entire system, no?

I replaced the mech fan with a 3-fan setup; one large puller (activated by the gasser wiring's low/high) & 2 9" pushers (one tied to fan-high, one over trans cooler, both w/manual switches). Desert temps, towing, etc.
Testing with all 3 fans on "High", Dorothy & Toto were flying around the engine compartment...
The manually-controlled dance between optimum operating temps and excessive heat should prove entertaining. Maybe that idea of a 2nd temp sensor @ egr-tap is a good one... later. Thanks again to all for piping-in with valuable info and insight.

Just a thought.
The heater core outlet coolant may have a reduced liquid temperature when you have the HVAC temperature control in the "HOT" position and the blower fan in the higher speed settings thus removing most of the heat from the liquid coolant going through the heater core heat exchanger due to the higher air flow.
But what about during hot summer time when the HVAC temperature control is set all the way to the "COLD" position and there is no air flow going through the heater core heat exchanger. The coolant temperature leaving heater core heat exchanger will still be at or very near the same as the temperature entering the heater core.
:ALONE:

Gypsy62 · **Posted:** Thu Jan 23, 2020 3:20 pm

That's true, but regardless whether the cabin fan/temp controls are set to hot, cold or off the coolant temp exiting the heater core cannot be any warmer than any other available coolant tap. Obviously, with the heater "On" (and fan blowing) heat is being drawn-off the heater core so its exiting coolant temp is lowered, benefitting the turbo feed.

The fact that the hoses to/from the core travel furthest may also help lower temps, but those runs are above the exhaust man so maybe not.

flash7210 · **Posted:** Thu Jan 23, 2020 3:38 pm

Well, look at this way. Hot coolant from the cylinder head was used to cool the egr gasses. So I guess that would work for the turbo too :juggle:

Gypsy62 · **Posted:** Sun Feb 02, 2020 4:55 pm

Flow Engineers: Free Beer!

So, it occurred to me that flow-VOLUME is being notably reduced due to the plugs (circled) inserted into both the thermo & pump housings. They represent a delete of the direct-feeds to/from the heater-core. The hc re-route is going to travel: oilcooler-hc-turbo-pump.
[The red line just illustrates the bypass-routing]

I'm wondering how the decreased volume is going to impact system performance. First, it seems like it will only be a factor thermo-closed. Thermo-open, the volume of flow through the radiator should easily exceed any constricted-volume concerns created by the two plugs.

Thermo-closed, in response to constricted flow-VOLUME the unchanged pump-force should result in elevated flow-PRESSURE, no?
How do folks think that Increased flow-velocity will impact the system?
Faster operating-temps from cold?
???

Thanks!
[Add'l notes: there are both fine & coarse threads for the hose-barb fittings tapped into the pump-housing, making interchangeability of barbs (& plugs) a pita. Also, the bypass-barb @ the thermo-housing is cast alum. not removable; angle-mod required cut/weld.]

A few more pics with the pump-housing & thermo installed.
The 3" turbo intake is just temp'd in:

photo upload sites

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Bonus Question: do the forces of Volume and Pressure exist in the vacuum of Outer Space?

flash7210 · **Posted:** Sun Feb 02, 2020 7:25 pm

If you are intent on using the oil cooler outlet, I'd go from oil cooler -> turbo -> heater core.

That will ensure that hot coolant, courtesy of the turbo, will be available to the heater core.

Quote:

Bonus Question: do the forces of Volume and Pressure exist in the vacuum of Outer Space?

Absolutely.
Outer space is zero BAR.
Here on earth, anything less than 1 BAR (14.7 psi) is considered vacuum. But vacuum is only relative to atmospheric pressure.

Questions re coolant routing

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