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

[Ericshere03]

I was sold on this oil cooler idea if I were to build my dream 4.6, 4.7 or 5.0 aluminum headed high compression stroker. But for STOCK 4.0 I’ll tell you I’ve had this engine on the desert floor pegged full throttle, 2500rpm for HOURS in 100+ degree weather with the AC full blast loaded with people and cargo…

The 4.0 don’t quit!!! It doesn’t care. In fact I’ve never had a vehicle with so consistent MPG, 14-16mpg, high way, city, driving conservatively or driving more spiritedly. It’s a tractor motor and just does its thing.

My current LJ has about 160k miles and I swear it runs as good as my first LJ with 12k miles on it … I’ve owned 6 TJ/LJ 4.0’s and they just do their thing!

Now! I keep my equipment maintained, good oil and fresh fluids, blah blah blah.

Just food for thought. I love the 4.0, only other engine I’d ever consider for a CJ, YJ, TJ era jeep is a small diesel.

 

[Captain Phoenix]

As for the Windstar intake, the answer to that is yes, and there is now hard data to back that up thanks to @Jezza in this thread (a few pages in):

From what I saw it looked like he was doing all the tests back to back but what people have reported is that any benefit from the Windstar intake diminishes over time as the PCM learns and adjusts to the new air density. It would be interesting to see how it does on the dyno after a few weeks of driving with the new intake.

 

[MikeE024]

That's what I was asking about. The OP cut his fitted hose and added a 90° fitting to connect the hose from the heat sink to the cut fitted hose. I was just going to get 5' of hose and not have a fitting like he did. (I'll use the fitted hose for the lower one, a gates heater hose isn't very expensive.)

View attachment 646405

You should be able to run a straight fitting, but if you had to do a 90*, I’d run an AN swivel fitting.

I have a straight fitting and a 90* fitting to and from my Wix coolant filter.

 

[MikeE024]

I was sold on this oil cooler idea if I were to build my dream 4.6, 4.7 or 5.0 aluminum headed high compression stroker. But for STOCK 4.0 I’ll tell you I’ve had this engine on the desert floor pegged full throttle, 2500rpm for HOURS in 100+ degree weather with the AC full blast loaded with people and cargo…

The 4.0 don’t quit!!! It doesn’t care. In fact I’ve never had a vehicle with so consistent MPG, 14-16mpg, high way, city, driving conservatively or driving more spiritedly. It’s a tractor motor and just does its thing.

My current LJ has about 160k miles and I swear it runs as good as my first LJ with 12k miles on it … I’ve owned 6 TJ/LJ 4.0’s and they just do their thing!

Now! I keep my equipment maintained, good oil and fresh fluids, blah blah blah.

Just food for thought. I love the 4.0, only other engine I’d ever consider for a CJ, YJ, TJ era jeep is a small diesel.

I run a turbo and my oil temps were only 5-10* more at the pan than my coolant temps after running it hard on the highway in 97* heat. I stopped caring once I had that info.

 

[Ericshere03]

I run a turbo and my oil temps were only 5-10* more at the pan than my coolant temps after running it hard on the highway in 97* heat. I stopped caring once I had that info.

Well dang … shut this thread down, who don’t ya ?

 

[Rickyd]

I run a turbo and my oil temps were only 5-10* more at the pan than my coolant temps after running it hard on the highway in 97* heat. I stopped caring once I had that info.

You don't have the oil/water cooler?

 

[MikeE024]

You don't have the oil/water cooler?

Correct, I don't have an oil/water cooler.

 

[Captain Phoenix]

You should be able to run a straight fitting

I'd prefer to not use any fitting, just use straight hose instead of the molded hose. I'll take a look when I get back in country and see what the routing looks like and if I really need the molded hose.

 

[MikeE024]

I'd prefer to not use any fitting, just use straight hose instead of the molded hose. I'll take a look when I get back in country and see what the routing looks like and if I really need the molded hose.

Of course, and that will be a judgement call.

I didn't like how much the straight hose bent when routed to the thermostat housing, so I utilized the 90* bend of the molded hose and then spliced in the straight aluminum fitting where it made sense to do so.

 

[SkylinesSuck]

From what I saw it looked like he was doing all the tests back to back but what people have reported is that any benefit from the Windstar intake diminishes over time as the PCM learns and adjusts to the new air density.

This is commonly repeated "knowledge" that isn't. Whoever claims it is just regurgitating crap they have heard on the Internet and letting their butt dyno convince them they have proof.

 

[Steel City 06]

This is commonly repeated "knowledge" that isn't. Whoever claims it is just regurgitating crap they have heard on the Internet and letting their butt dyno convince them they have proof.

I don't even understand how the PCM could adjust to make less power here.

Presumably the VE tables will be somewhat off when a new intake system is installed. The PCM will quickly adapt in short term fuel trims, and will learn via long term fuel trims as well.

However, for the density part of the equation, the PCM is programmed to ensure that 100% of the oxygen coming through is used up in combustion by the time it leaves the catalytic converter. Even as the PCM adjusts in short term or long term fuel trims, it doesn't actually change the mass of air entering the cylinder at a given RPM and throttle position. That is determined by pure fluid dynamics.

If anything, it would result in a slight increase in efficiency and power over time as it learns via LTFT since LTFT corrections are applied proactively rather than reactively.

Running open loop at WOT as some tunes do might change the equation a bit, but it doesn't change the simple fact that more air makes it into the cylinder in the first place.


In a really poorly tuned and really poorly running engine, I could potentially see one way that power might decrease from initial results, and that would be if the PCM is massively overcompensating at first for the change in airflow by running excessively rich (which can create slight gains in power), but then eventually learning the correct stoichiometric ratio. But that would be indicative that there is a much worse problem at play that needs to be fixed. Or alternatively, that simply tuning to run in open loop and run rich all the time might get slightly more power (at the cost of melting your catalytic converters).

 

[SkylinesSuck]

I don't even understand how the PCM could adjust to make less power here.

Presumably the VE tables will be somewhat off when a new intake system is installed. The PCM will quickly adapt in short term fuel trims, and will learn via long term fuel trims as well.

However, for the density part of the equation, the PCM is programmed to ensure that 100% of the oxygen coming through is used up in combustion by the time it leaves the catalytic converter. Even as the PCM adjusts in short term or long term fuel trims, it doesn't actually change the mass of air entering the cylinder at a given RPM and throttle position. That is determined by pure fluid dynamics.

If anything, it would result in a slight increase in efficiency and power over time as it learns via LTFT since LTFT corrections are applied proactively rather than reactively.

Running open loop at WOT as some tunes do might change the equation a bit, but it doesn't change the simple fact that more air makes it into the cylinder in the first place.


In a really poorly tuned and really poorly running engine, I could potentially see one way that power might decrease from initial results, and that would be if the PCM is massively overcompensating at first for the change in airflow by running excessively rich (which can create slight gains in power), but then eventually learning the correct stoichiometric ratio. But that would be indicative that there is a much worse problem at play that needs to be fixed. Or alternatively, that simply tuning to run in open loop and run rich all the time might get slightly more power (at the cost of melting your catalytic converters).

But Jerry knows the father of the Rubicon on Facebook!!!!

 

[Captain Phoenix]

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

I did that one and it's working fine so far. I never really paid attention to oil pressure before but I want to say it's a touch higher now.

The Mopar part needs 5/8" hose so I bought a small roll of 5/8" heater hose and just used that.

This is the oil pressure at about 3,000 RPM.

 

[Captain Phoenix]

I didn't like how much the straight hose bent when routed to the thermostat housing

I used the Mopar oil cooler which has 5/8" fittings so it's the lower heater hose that goes to the water pump pipe so no 90° bend. I just used regular hose and I'm going to try to return the molded hose.

 

[MikeE024]

I used the Mopar oil cooler which has 5/8" fittings so it's the lower heater hose that goes to the water pump pipe so no 90° bend. I just used regular hose and I'm going to try to return the molded hose.

Great to hear you pulled it off. I ended up going a different route by installing a remote coolant filter that I’m pretty happy with.

 

[lBasket]

Correct, I don't have an oil/water cooler.

Isn't the block an oil water cooler

 

[Steel City 06]

I did that once and it's working fine so far. I never really paid attention to oil pressure before but I want to say it's a touch higher now.

The Mopar part needs 5/8" hose so I bought a small roll of 5/8" heater hose and just used that.

View attachment 665511


This is the oil pressure at about 3,000 RPM.

View attachment 665512

Awesome install! I assume that filter stem requires no thread adapters?

As for oil pressure, I think it goes into relief/bypass mode at about that gage position. So you won't see any higher than that unless something is broken. The exchanger does add a small additional restriction which may increase measured oil pressure since it reads pressure before filter (I think).

That said, even with the slight increase in restriction, you'll still have more oil flow on average during warmup than before since the oil is being actively heated. You'll have ever so slightly less than before once fully warmed up, but it doesn't matter as the oil system is already oversized in order to ensure adequate flow during warmup. (Even if it did matter, the effect can be more than negated by going to a larger filter like the M1-301A.)

 

[Captain Phoenix]

I assume that filter stem requires no thread adapters?

Correct. That's why I liked the idea of the Mopar part, easier retrofit.

 

[Captain Phoenix]

Isn't the block an oil water cooler

I'm going to say no. The oil cools the block from one side and the water cools the block from the other side but it's not an oil/water heat exchanger.

 

[Steel City 06]

Isn't the block an oil water cooler

Technically, yes. However the block nowhere near as efficient as a thin-plate heat exchanger. In order for the heat to be transferred between the two, the block needs to heat up significantly, which takes time. The thin-plate exchanger has very little thermal mass in comparison. So the oil gets hot much faster. It also provides a much faster path to cool the oil as it heats up during periods of heavy load. (Also, in general, without a dedicated heat exchanger, the vast majority of the heat going into the oil is coming from combustion gases rather than coolant.)

In addition, warming oil through the block requires a temperature gradient in the block. Whenever a temperature gradient is created, this creates thermal expansion stresses in the block that only equalize once the temperatures equalize.

So every time you have a cold-start drive cycle, you create a stress cycle. In itself it doesn't matter as the block is more than capable of withstanding it, but it does limit the lifespan as a function of metal fatigue. Generally, engineers will design the block to meet a certain number of stress cycles, meaning the design life is finite.

By using a thin-plate heat exchanger with the oil and coolant, you drastically reduce the thermal gradient between those passages which thereby reduces the thermal expansion stresses and thusly extends the fatigue life of the block and some adjacent components. (One of many reasons why modern engines last so much longer than engines from the 1990s and early 2000s...)