How to install a Ecoboost oil cooler / heater in a 4.0 and why

[Steel City 06]

After falsely blaming my last oil cooler (an oil to air heat exchanger with a thermostat) for a loss of oil prime (actually was a bad oil pump) and tearing it out, I decided to take a look around and see if there was a simpler and more effective option.

Then I remembered my 3.5 Ecoboost F-150 has an oil cooler. In fact, it is intended to both heat AND cool the oil, using the heat from the coolant.

In short, coolant is warmed by the engine, pumped through the heat exchanger (sandwiched between the filter and the block), exchanges heat with the oil, and then recirculates through the engine and/or radiator to pick up or dump out more heat.

Unlike the typical aftermarket oil coolers (which are performance focused only), the oil to coolant heat exchanger not only cools the oil once it gets hotter than the coolant temperature, it also heats the oil when the engine is still warming up. Oil heats up much more slowly than coolant, and in most engines, the radiator will begin dumping excess heat long before the oil has hit its operating temperature.

Why is this important?

1. Fuel economy (and emissions, to a lesser degree) - warm oil is less viscous and takes less energy to pump than cold oil. In addition, it also flows more easily and reduces parasitic drag on the engine. Addition of a oil to coolant heat exchanger is proven by OEMs to reduce fuel consumption, especially in the first 15-20 minutes of driving.

2. Engine wear - oil at its operating temperature lubricates more effectively than cold oil. The faster you heat it up, the less wear the engine receives during the warm-up cycle. This can also be achieved through the use of specialty oils (like 0W-30), but that is generally cost-prohibitive.

3. Performance - cooling the oil once it passes the temperature of the coolant helps reduce engine wear, helps maintain the engine at a more consistent temperature, and can even reduce the need of the engine to pull timing due to high temperatures. In effect, the oil cooler allows the engine to be run hard with much less impact and resulting wear. Effectively, an oil cooler turns the oil into a second coolant.

4. Extended oil life - the heat exchanger has the dual benefit of preventing the oil from overheating and also heating it up to operating temperature in a matter of minutes. The faster heat-up helps drive out condensation that can degrade the oil, especially on cars driven short distances. Reducing the peak temperature of the oil drastically improves oil life, especially as the oil passes 250°F, which might be seen at a track, idling on a really hot day, or climbing a hill on the freeway. This heat exchanger is partly why so many new cars can have 10,000+ mile oil change intervals, including the Ecoboost F-150s.

So, how do I install one in my TJ?
Simple. Buy 3 feet of 3/4 coolant hose, a long male to female nipple extension, an Ecoboost heat exchanger, a coolant elbow, and a few constant tension clamps. Install as shown:

The heat exchanger just sandwiches between the oil filter and the engine. Simply plumb the heat exchanger in series with the heater core (the larger of the two hoses). You don't even need to drain the oil or the coolant to make the connections (a little will spill out).

The hardest part of this was finding a nipple extension long enough to connect the oil filter to the nipple on the engine block. I ended up buying a round blank and drilling/tapping it to 1/2-20 UNF, and then using a sealant to insert a second male to male nipple.

Following the install of the heat exchanger, I've noticed that the engine (coolant) does take a bit longer to hit operating temperature since it is heating the oil as well. However, I've also noticed the engine more quickly approaches a more stable state, much like when you've been driving for 30+ minutes. City fuel economy has likely improved, but due to a whole lot of extraneous factors, I can't really quantify. It also seems to have increased the pinging threshold somewhat, meaning I can be slightly more aggressive with timing on 87 octane.

Interestingly, it also seems to temper the fluctuations in the coolant temperature due to changing loads. Since the oil acts as both a heat sink and a heat source at various times, it moderates the temperature of the coolant quite well.

Part number for the heat exchanger: ML3Z6A642A
Alternatively, look up an oil cooler for a 2021 Ford F-150 3.5 Ecoboost (non-hybrid).

This exchanger is probably a bit oversized for the TJ, given the Ecoboost runs at twice the horsepower and 20 PSI of boost. However, since it is a coolant to oil heat exchanger and not just an oil cooler, having an oversized cooler will not overcool (or overheat) the oil.

 

[Link]

Neat!

 

[Steel City 06]

After a couple weeks of running it, I have noticed a few things:

The engine coolant temperature seems to rise quickly at first, but takes a while to reach full temperature. This is likely because of how much heat is being transferred to the oil. It also means the heater is a bit weaker for the first 10 minutes or so of driving, but not so much as to cause an issue. The coolant goes through the cooler first and then the heater core, meaning the oil cooler gets the hotter coolant.

It does a very good job of tempering spikes and drops in the engine coolant temperature, which keeps things running consistently. It obviously does not increase the overall cooling capacity of the car, but it acts as a thermal reservoir.

I have only just started measuring (numbers hopefully to follow), but I have noticed significant reductions in fuel consumption in city driving. It seems the engine will tolerate lower RPMs much sooner than it did without the cooler, allowing me to get much better fuel economy. I've been running at long periods as low as 1500 RPM without significant lugging, and still having reasonable power.

That said the increase in economy is probably due to a number of factors, the biggest being the tune I am using on the engine. Simply drastically cutting back when the engine pulls timing seems to have by far the biggest impact on both power and fuel economy. I haven't perfected it yet, as I still have a few areas of pinging, but I hope to mitigate those by installing the Windstar air intake to lower the IATs and thereby increase the detonation threshold. Generally, I have noticed pinging begins at higher IAT and higher ECT, but IAT seems to have the bigger impact. Higher octane eliminates the detonation, but the increased cost of that fuel negates any fuel savings.

I'm also running 48 PSI in 35x12.5, which actually feels fine on the road, contrary to what I expected. It actually seems to have tightened up the feel of the steering, and of course, lowered the rolling resistance. I also only have 4.10s, which I am increasingly convinced I will keep instead of regearing.

 

[Ericshere03]

I appreciate your observations!

Id argue that you actually ARE increasing cooling capacity. That hotter oil will shed more heat. That warmer oil also aids in keeping the oil clean and more viscous… this is a good thing.

I found a mopar part that will work, and looks exactly the same.

Just gave me a reason to give this a shot!

I was also planning on running my power steering through the ATF cooler on my radiator.

 

[Ericshere03]

here is the Mopar version that should work for us, the car it comes from uses the same filter as us

4792912AE

 

[chili_pepper]

Just caught this thread, very interesting. It sounds like you're tweaking other things as well, wondering what net effect this might have on a basically bone stock rig.

My "LJ escape pod" is an '04 BMW MINI Cooper S running a 1.6L supercharged four pot, and it actually uses a heat exchanger similar to this from the factory.



I hadn't really taken notice of it until I overhauled the cooling system a few years a go. Given the limited underhood space, the cooling piping is quite, uh, interesting, to say the least (only part of it below)...



I know it works on this engine, but this one's a bit high strung compared to our 4.0 AMC lumps.

I'm watching this thread....

I'm also running 48 PSI in 35x12.5, which actually feels fine on the road, contrary to what I expected. It actually seems to have tightened up the feel of the steering, and of course, lowered the rolling resistance.

I never run below 32-35 in my 31x10.50 KO2's for road use. I can confirm your findings.


And last but not least....are you a Pens fan?

 

[freedom_in_4low]

Nice find, I like it. I don't know about the performance stuff (without a tune) but warming it up faster to boil off water and fuel dilution on short trips is definitely a win.

Looks like I'd have to go to the Mopar filter instead of the FL1A I usually run but I guess the advantages of the cooler probably outweigh the extra 3oz of capacity

here is the Mopar version that should work for us, the car it comes from uses the same filter as us

4792912AE

Some of the photos on that one appear to show the nipple extension as though it's included, which would be nice.

 

[Steel City 06]

You can adapt it to just about any filter thread you want. I had to make my own nipple extension as the one that came in the kit was M22-1.5 at both ends, but the TJ is 3/4-16. No reason you couldn't adapt it to a different thread at the same time. I chose to stick with the M1-301A filters since they're the same diameter as the standard TJ filter but much taller, so reduced pressure drop across the filter.

If you can find one that comes with a 3/4-16 filter nipple extension, that would certainly be the easiest and most bolt-on solution. The one @Ericshere03 posted is certainly a good find

 

[chili_pepper]

You can adapt it to just about any filter thread you want. I had to make my own nipple extension as the one that came in the kit was M22-1.5 at both ends, but the TJ is 3/4-16. No reason you couldn't adapt it to a different thread at the same time. I chose to stick with the M1-301A filters since they're the same diameter as the standard TJ filter but much taller, so reduced pressure drop across the filter.

If you can find one that comes with a 3/4-16 filter nipple extension, that would certainly be the easiest and most bolt-on solution. The one @Ericshere03 posted is certainly a good find

I wonder how much difference there is in size between the Ford and Mopar units...

 

[freedom_in_4low]

You can adapt it to just about any filter thread you want. I had to make my own nipple extension as the one that came in the kit was M22-1.5 at both ends, but the TJ is 3/4-16. No reason you couldn't adapt it to a different thread at the same time. I chose to stick with the M1-301A filters since they're the same diameter as the standard TJ filter but much taller, so reduced pressure drop across the filter.

If you can find one that comes with a 3/4-16 filter nipple extension, that would certainly be the easiest and most bolt-on solution. The one @Ericshere03 posted is certainly a good find

Mine is just the Motorcraft version of the same one you're using. My comment was simply due to me not being sure there would still be room for the extra length with the cooler stacked in there. Looks like it still fits for you.

 

[NskLJ]

Can you use the Mopar nipple to attach it to the engine block

 

[freedom_in_4low]

Just caught this thread, very interesting. It sounds like you're tweaking other things as well, wondering what net effect this might have on a basically bone stock rig.

My "LJ escape pod" is an '04 BMW MINI Cooper S running a 1.6L supercharged four pot, and it actually uses a heat exchanger similar to this from the factory.

View attachment 461446

I hadn't really taken notice of it until I overhauled the cooling system a few years a go. Given the limited underhood space, the cooling piping is quite, uh, interesting, to say the least (only part of it below)...

View attachment 461447

I know it works on this engine, but this one's a bit high strung compared to our 4.0 AMC lumps.

I'm watching this thread....




I never run below 32-35 in my 31x10.50 KO2's for road use. I can confirm your findings.


And last but not least....are you a Pens fan?

I had a 2008 Cooper S, which had a turbo instead of a supercharger.

The cooling system was my favorite.

The main water pump was of course on the crank pulley end of the engine, the thermostat was on the transmission end, and was plastic and electronic and close to $200, so I was really happy when that cracked and started dumping coolant. There was also a crossover pipe that ran across the length of the engine, which of course was also plastic and crack prone; and buried under the intake manifold. There was a secondary water pump that was electric, with it's own set of hoses, just to circulate coolant through the turbo after shutting the engine off. And of course all of it is crammed into the smallest engine compartment I've ever seen.

 

[chili_pepper]

The main water pump was of course on the crank pulley end of the engine

Mine's actually driven directly off the supercharger, a potential Achilles heel.

the thermostat was on the transmission end, and was plastic

A "yep" to both of those.

all of it is crammed into the smallest engine compartment I've ever seen.

It is tight, but having owned the vehicle longer than any other and done all the service work myself, with the right tools and information (Bentley Bible), I've actually found it relatively easy to work on.

I've taken a lot of guff for owning it, but it's by far the best vehicle I've had and still puts a smile on my face every time I drive it. Basically, it's a go-kart for grown-ups. The LJ seems to be following suit...I smile every time I drive it and if i have my way, I will be driving it for a long time to come.

 

[freedom_in_4low]

Mine's actually driven directly off the supercharger, a potential Achilles heel.



A "yep" to both of those.



It is tight, but having owned the vehicle longer than any other and done all the service work myself, with the right tools and information (Bentley Bible), I've actually found it relatively easy to work on.

I've taken a lot of guff for owning it, but it's by far the best vehicle I've had and still puts a smile on my face every time I drive it. Basically, it's a go-kart for grown-ups. The LJ seems to be following suit...I smile every time I drive it and if i have my way, I will be driving it for a long time to come.

View attachment 461652

Mine was for sure a blast to drive. The kids called it a racecar because it had stripes and is probably the quickest thing I've had in their lifetimes.

And even the small size was big enough to haul a Jeep axle to the shop for a regear

I just got tired after a year of what seemed like nonstop issues, I think stemming from a lack of maintenance by previous owners. I heard from the guy that bought it from me about 6 months after, and he was in for a new engine after losing all compression on cylinder 2. I felt bad because I'm me but no idea what could have caused it.

 

[chili_pepper]

I just got tired after a year of what seemed like nonstop issues, I think stemming from a lack of maintenance by previous owners

I was very fortunate in that I purchased mine from a family acquaintance at 4 years old with only 21k on the clock and full service records. From there It was just a matter of learning and maintaining.

Still a good little car and I doubt I'll ever get rid of it. They carry much used value anymore, so probably nothing in it. I've considered turning it into a track day car, but those of you who've done that kind of thing know it isn't necessarily cheap. My surplus funds have now been diverted to Tess (the recently acquired LJ).

Always liked that BRG metallic with tan interior combo. Obviously, I didn't have choice of color, and while I do like the Chili Red, I might have gone for something a little less noticeable but the deal was hard to pass on as she was...and the Chili Pepper was born.

Didn't mean to hijack this very interesting thread, so back to the oil cooler talk. Have you done this heat exchanger mod as well on your LJ? The potential benefits of doing it do have me intrigued and I'm glad I caught this one.

 

[Steel City 06]

Windstar intake installed. Certainly a different sound...

With the combination of the exchanger, the tune, the 12-hole injectors, and the Windstar intake, I seem to have increased the detonation threshold to the point that I can run 1,300 RPM at near WOT continuously without pulling timing or making it crazy rich. It also has an impressive amount of torque at such low RPMs.

Probably not as much to do with the cooler as everything overall, but very interested to see if it does result in better fuel economy.

 

[Ericshere03]

Windstar intake installed. Certainly a different sound...

With the combination of the exchanger, the tune, the 12-hole injectors, and the Windstar intake, I seem to have increased the detonation threshold to the point that I can run 1,300 RPM at near WOT continuously without pulling timing or making it crazy rich. It also has an impressive amount of torque at such low RPMs.

Probably not as much to do with the cooler as everything overall, but very interested to see if it does result in better fuel economy.

View attachment 461805

Since you’re obviously obsessed about milking that motor. I been wanting to ceramic coat my exhaust manifolds (dual cast iron type), gut my pre cats (I can fool the sensors) and ceramic coat the down pipe… or buy some long tube headers and ceramic coat them…

I was also going to ceramic coat the OUTSIDE of my intake manifold with the shiny stuff, in theory it should also drop the intake air temps a bit.

I also have a new 98 fuel rail with the pressure port and without the damper I was going to ceramic coat the outside to keep fuel cooler and perform the 12 port injectors.

Removing all that heat more efficiently can’t be a bad thing.

 

[Steel City 06]

Well, 1st tank with the these mods and I get 15.4 MPG city and mountains. I'm used to closer to 12-13 mpg. I think if I can clean up the tune and do a couple small additional improvements, I can get 1-2 mpg better.

15.4 mpg would indicate a roughly 20% reduction in fuel consumption since I first flashed a tune and started retrofitting parts, which is huge. At 10,000 miles a year, that's $600 in fuel per year. But it also means every tank gets me an extra 50-60 miles, which is an additional hour of driving time before having to fill up. (If I manage to get it up to 17 mpg, that would be a 26% reduction in fuel consumption, and could save $850 a year, and increase the range by 90 miles...)

Note I have the run-of-the-mill 35x12.5 on 5.5" of combined lift. It is also a Rubicon model with heavy steel bumpers and tire carrier. So not surprisingly, my fuel economy is abysmal to begin with.

As for how much fuel economy gain is due to this heat exchanger in particular, it is very hard to say. It certainly has a big impact on city driving since it heats the oil up faster, but it seems to also have a small benefit on highways at reducing detonation, allowing me to keep more aggressive timing while staying stochiometric in closed loop.

I would guess it will pay itself off in the course of 1-2 years, even before accounting for savings associated with increased oil/engine life.

Maybe I need to chase 20 mpg on 35s for the heck of it...

 

[chili_pepper]

Well, 1st tank with the these mods and I get 15.4 MPG city and mountains. I'm used to closer to 12-13 mpg. I think if I can clean up the tune and do a couple small additional improvements, I can get 1-2 mpg better.

15.4 mpg would indicate a roughly 20% reduction in fuel consumption since I first flashed a tune and started retrofitting parts, which is huge. At 10,000 miles a year, that's $600 in fuel per year. But it also means every tank gets me an extra 50-60 miles, which is an additional hour of driving time before having to fill up. (If I manage to get it up to 17 mpg, that would be a 26% reduction in fuel consumption, and could save $850 a year, and increase the range by 90 miles...)

Note I have the run-of-the-mill 35x12.5 on 5.5" of combined lift. It is also a Rubicon model with heavy steel bumpers and tire carrier. So not surprisingly, my fuel economy is abysmal to begin with.

As for how much fuel economy gain is due to this heat exchanger in particular, it is very hard to say. It certainly has a big impact on city driving since it heats the oil up faster, but it seems to also have a small benefit on highways at reducing detonation, allowing me to keep more aggressive timing while staying stochiometric in closed loop.

I would guess it will pay itself off in the course of 1-2 years, even before accounting for savings associated with increased oil/engine life.

Maybe I need to chase 20 mpg on 35s for the heck of it...

I might have missed it, but have you given a rundown of all the mods you've done to get to this point?

While how one drives has a big effect on fuel efficiency (regardless of vehicle), all things being equal I feel like there might be more in it if not turning larger tires and hauling the associated beefier bumpers and the like. Becoming more and more tempted to try this...seems like there's the potential for multiple benefits.

 

[freedom_in_4low]

Well, 1st tank with the these mods and I get 15.4 MPG city and mountains. I'm used to closer to 12-13 mpg. I think if I can clean up the tune and do a couple small additional improvements, I can get 1-2 mpg better.

15.4 mpg would indicate a roughly 20% reduction in fuel consumption since I first flashed a tune and started retrofitting parts, which is huge. At 10,000 miles a year, that's $600 in fuel per year. But it also means every tank gets me an extra 50-60 miles, which is an additional hour of driving time before having to fill up. (If I manage to get it up to 17 mpg, that would be a 26% reduction in fuel consumption, and could save $850 a year, and increase the range by 90 miles...)

Note I have the run-of-the-mill 35x12.5 on 5.5" of combined lift. It is also a Rubicon model with heavy steel bumpers and tire carrier. So not surprisingly, my fuel economy is abysmal to begin with.

As for how much fuel economy gain is due to this heat exchanger in particular, it is very hard to say. It certainly has a big impact on city driving since it heats the oil up faster, but it seems to also have a small benefit on highways at reducing detonation, allowing me to keep more aggressive timing while staying stochiometric in closed loop.

I would guess it will pay itself off in the course of 1-2 years, even before accounting for savings associated with increased oil/engine life.

Maybe I need to chase 20 mpg on 35s for the heck of it...

Is there any indirect knock detection taking place that pulls timing on a stock tune or would a tune be required to realize any of that particular benefit?