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Still high EOT a after new cooler and cooler bypass valve HELP?

17K views 42 replies 11 participants last post by  vitaminjoe 
#1 ·
I apologize ahead of time that this is so long but I want to make sure I cover everything I can think of.

Ok I've done oil cooler 3 times in 2 years now, after this time the delta was 20+ degrees the next day. After research and weeks of looking for a new bypass valve I found that BPD sells them for $20 without having to buy the whole housing, installed it today and went out for a test. Air temp outside was around 50 coolant 189-199 oil got up to 225 before I got off the highway (it seemed to be still climbing). I'm about to beat my head against the wall what else could cause this? Truck has 175k miles stock bolts, gaskets, injectors, turbo, sct tunes by Tony Wildman, straight 4", custom egr delete(made my own delta kit by plugging front cover where it comes out of intake and rerouting coolant out of the cooler and back into the heater hose under the degas bottle. Also the truck will lose coolant and get hot but only if on the highway for extended time pulling a load (im thinking it's flash boiling the coolant in the oil cooler because the oil is getting so hot, can't test that theory till I fix the EOT problem though) otherwise it will keep the same coolant level for weeks, no signs of head gasket problems that I can find.

I do work at a shop on my days off from the FD, I don't consider myself anywhere close to a real mechanic especially diesel but I have turned a wrench or 2, that being said I have access to pretty much any tool you could think of so someone please just tell me what I can try.

Thank you so much!

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#2 ·
If I'm understanding you correctly, it sounds like you've bypassed the oil cooler as well.

 
#3 ·
OEM oil cooler or one from Sinister, et al?

My guess would be insufficient coolant flow through the cooler due to your version of an EGR delete. Possibly a kinked hose or a dead head problem. Try running it with the heater on and see if affects the delta.
 
#4 ·
S20055 the bypass is where the coolant comes out of the oil cooler and would normally go into the egr cooler/delete. I just did away with the return through the intake to the front cover and rerouted it to under the degas bottle same way ipr's delta kit does.

G8orFord thank you for your thoughts on the issue I'll check the hose for kinks and I'll try it with heater on tomorrow to see if anything changes.

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#6 ·
I tried that once. You need to remove that plug you installed on the front cover that's your problem. You have to realize the oil cooler is nothing more than a heat exchanger. When you plug the port on the front cover you're letting coolant rush through the cooler too fast so It doesn't have time to cool the oil. Remove the plug. Your problem will be solved. Reroute the hose from the intake. Trust me. I pulled almost all my hair out trying to figure this out


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#12 ·
Help me out with this one Sean. I can't see how high coolant velocity through the cooler could cause higher oil temps. The coolant should be a relatively constant temperature and increased velocity shouldn't make much difference in its ability to transfer heat from the aluminum. Now oil flowing through too fast may not get cooled very well, and coolant moving to slow may cause higher temps from heat saturation (clogged cooler), but I'm not seeing the problem with high coolant flow. More coolant at a lower temp should transfer more heat from the cooler the way I see it. But I've been wrong before.
 
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#7 ·
s20055 I haven't really found anything out I can't find a kink in the hose and when I turn the heater up the coolant temp comes down but oil temp keeps rising.

LoxDiesel let me get this straight I need to remove the plug in the front cover and then reroute that coolant path to where? Do I still leave the coolant coming out of the oil cooler going to the heater hose under the degas bottle? If so how does the coolant moving through the intake/front cover change the speed of the coolant through the oil cooler?

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#9 ·
No the delta kit was added same time as oil cooler being replaced so hard to say. The delta kit that you buy and numerous people are using plugs the coolant there also so why does theirs work and mine doesn't or it works on some trucks at least?

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#15 ·
Im sorry i have to agree with G8orFord on this one... Coolant going thru cooler faster = better heat exchange... if it goes slower, that allows the coolant more time to heat up which would then reduce the efficiency of the cooling affect... Regardless of how fast the coolant is moving, the oil will be in contact with coolant.. would it not?
 
#17 ·
If the coolant is moving slow enough to heat up from the oil (heat transfer) than it is working correctly. It the coolant is flowing too quickly to heat up from the oil (no heat transfer) than it is not working correctly and you will run higher EOT.


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#19 ·
Hahahahaaa, but really...whatever man.

Does the coolant heat up because it's pulling heat from the oil? Or does the oil cool down because it's pulling "coolness" from the coolant?

Riddle me this Batman, why do you have a radiator?

Heat is transferred from oil to coolant, thus cooling the oil and heating the coolant; heat is then transferred from coolant to air, thus cooling the coolant.


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#20 ·
Lol Here we go putting words in my mouth... I said that the coolant moving thru the cooler faster will not cause higher oil temps... Let's use your radiator comparison now that you've brought it up.. If the heat is transferred to the coolant like you say .. That means the faster the coolant gets to the radiator it will get rid of that heat faster... I guess this is rocket science for Ya and usually people get mad when they don't know what their arguing about
 
#25 ·
Okay if you say so
 
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#26 ·
So let me ask because now you guys have me lost. Why is his coolant moving too fast through the system. Did you install a smaller pulley ?

Aside from that , your water pump fins could be cracked or broken not pumping enough coolant fast enough through the system causing the eot to rise although the radiator is cooling the ect.

Back when I built race cars we used air to water intercoolers and would need to compensate for the resivoir capacity to properly cool the charge air. Why .. because if there wasn't enough coolant in the system the intercooler / heated air would see the same coolant twice in one pass and therefore wouldn't cool down enough prior to making its way past the intercooler again.

Your issue is either 1) your water pump isn't working the way it should be 2) you didn't flush the system and something is clogging the cooler 3) you installed one of your delta mods incorrectly and it's blocking coolant flow.

I will bet money your system isn't seeing enough coolant / have a leak.

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#27 ·
They are trying to say that coolers that allow coolant to move to fast through it, will cause insufficient cooling for the oil ... Which in my mind it would be the other way around but i guess I'm wrong
 
#35 ·
You all are overlooking one vital piece in the cooler puzzle. The coolant does not cool (or remove heat from) the oil. The coolant removes heat from the aluminium structure. The aluminium structure, in turn, removes heat from the oil. I'm not arguing the point with anyone, but my feeble mind can't grasp the idea that more coolant at a lower temperature would not remove heat faster or at least as fast as less coolant at, what one would assume to be, a higher temperature.
 
#43 ·
You all are overlooking one vital piece in the cooler puzzle. The coolant does not cool (or remove heat from) the oil. The coolant removes heat from the aluminum structure. The aluminum structure, in turn, removes heat from the oil. I'm not arguing the point with anyone, but my feeble mind can't grasp the idea that more coolant at a lower temperature would not remove heat faster or at least as fast as less coolant at, what one would assume to be, a higher temperature.
This is a good point. In an exchanger like this, there are three heat transfer operations:

1. Heat from the hot fluid to the inner wall of the hot side (convective)
2. Heat through the wall of the exchanger (conductive)
3. Heat from the wall of the exchager to the cold side (convective)

For our oil coolers, operation 2 is usually affected by a build-up of gunk from the coolant itself. The more silicate deposit and other junk in the coolant system reduces the conductive heat transfer between the coolant and oil sides of the exchanger. Eventually the coolant passages are clogged completely and the flow-rate/heat transfer rate drops to zero.

Heat exchangers have a few factors to consider:

1. The heat transfer co-efficient. This is generally the number that represents how the metal casing conducts the heat from one side to another. It also includes the mass flow rate, specific heat capacity of the fluids, etc.
2. The surface area of the exchanger.
3. The logarithmic mean temperature difference (LMTD). This gets technical, but whatever: https://en.wikipedia.org/wiki/Logarithmic_mean_temperature_difference

A faster fluid flow is generally a good thing. Higher fluid velocity usually increases turbulence in the fluid which helps to pull heat from the metal walls of the exchanger. By the looks of it, the passages in the oil cooler are designed to induce some turbulence which aids in thermal transfer. High turbulence also reduces the chance of any solids settling out of the fluid.

The more coolant flow through the cooler will cool the exchanger faster. Time in the exchanger has little to do with it... in fact, you'd be hard pressed to find a heat exchanger forumla or calculation that takes time into effect. Surface area is the bigger factor. It's all flow rate, surface area and heat transfer co-efficient. (Although, I guess if you have a bigger exchanger and the same flow rate, the fluid would be in contact with the exchanger for more time.)

The Sinister oil cooler has larger, but fewer passages. This increases the flow rate, sure, but it more importantly decreases the surface area. In order to make the passages bigger, they had to take out a layer or two, since the cooler as a whole is the same physical size. Same is true of the updated Ford oil cooler. The 3C3Z-3A642-AA has fewer passages than the 3C3Z-6A642-CA. Guys running with the 3C3Z-6A642-CA will have lower oil temps than the original coolers. Surface area is key.
 
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#36 ·
Forgive me if I seem blunt about the issue. But, this trial was done on 3 trucks when the egr was removed and a new cooler was installed. All 3 had the same result and I had to pull the intake and remove the plugs. They all went back to normal


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#37 ·
Like I said, I'm not arguing. I'm sure your results are valid. Just having a hard time wrapping my head around it.
 
#39 ·
My brain hurts
 
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