Making sense of the temp delta... Trying to think it through.

[Dante04SRT]

Since getting my gauges installed, I've noticed about an 8-10* delta between my oil & water temp. I have done the complete swap and ELC swap but unfortunately didn't have the extra gauges beforehand, so I have no idea if it changed at all...

That being said, I began to think about why the delta matters. If I understand the logic correctly, if the oil temp is more than 15* warmer than the coolant temp, it means that the coolant passages in the oil cooler are somewhat clogged and restricting coolant flow. In my case, my ECT is around 180-184* and my oil temps never exceed 190-195*. NOW - In thinking further - Aside from the coolant hitting a bottleneck, the cooler is still working well enough as the oil temps are still well within acceptable levels. Isn't that the main concern?

I'm trying to think of the harm of a large delta (15*-25*)... Even if my EOT reached 20*, my ECT would most likely still be say 180* and my EOT would be 200*. Both of those numbers independently still sound pretty good.

Realizing of course that a high delta means that the cooler isn't as efficient as it SHOULD BE, but in the case of oil potentially only being 200-205*, where is the harm? I don't have the EGR system anymore and assuming my temps are both in fine shape, I don't think I'm at risk of engine damage, right? I mean, if its the coolant side of the oil cooler that gets clogged, but the ECT is still consistently low, what harm is there? This would also suggest that the oil side of the oil cooler is flowing just fine, so it's not like a blockage is there to prevent the oil from flowing at a high enough rate to keep the bearings safe.

It's really late here so I hope I've articulated the point I'm trying to make well enough. Basically, even if your ECT/EOT delta is high; what is the overall harm being done if both temps are still within spec and the emissions systems have been deleted?

[colo_dually]

With the deletion of the EGR Cooler, you are safer however there can still be an issue.

That issue is this, and from what I have seen/read it doesn't happen often. You have coolant flowing at X rate with a clear cooler. Once that cooler starts to clog you begin building additional pressure in your oil cooler. That pressure can cause a rupture internally to the oil cooler. Now you have either a coolant in oil, or an oil in coolant situtation. Both of which will cause damage.

The 15* delta is paramount on a stock EGR cooler. As an indication that there is such a restriction in coolant, which causes the EGR cooler to overheat and fail internally.

That's my understanding, anyway.

[RodeoPapaStroker]

The delta being 15+ doesn't hurt your engine as long as your temps are within range. The high delta is simply a warning of eminent failure of the coolers resulting in many issues, including coolant in your oil. I Have a BulletProof EGR cooler & external oil cooler. After I first installed them I test drove and had deltas higher than what I understood were safe, oil temps being cooler than ECT. Turns out, with help from the ORG, that deltas mean nothing to me because of my external oil cooler as long as all my temps are w/in range.

The deltas only indicate how well your stock style system is working..or not!

What're you doin up so late?

[RodeoPapaStroker]

Originally Posted by colo_dually

With the deletion of the EGR Cooler, you are safer however there can still be an issue.

The 15* delta is paramount on a stock EGR cooler. As an indication that there is such a restriction in coolant, which causes the EGR cooler to overheat and fail internally.

As per Ford engineers..

[2 stroker]

Brian said---
In my case, my ECT is around 180-184* and my oil temps never exceed 190-195*.
You have a t/stat that is stuck open, a stock Ford t/stat starts to open at 192.2* and is fully open at 219.2* running cold is also bad on these motors.
2 stroker

[Dante04SRT]

Originally Posted by 2 stroker

You have a t/stat that is stuck open, a stock Ford t/stat starts to open at 192.2* and is fully open at 219.2* running cold is also bad on these motors.
2 stroker

That's what I thought at first, too. The P/O installed a fuel pressure and ECT gauge in before I bought it so I was able to verify temps before my swap to ELC. As part of my coolant flush and ELC swap I also replaced the thermostat with a stock Ford one. Even with the new 'stat, I'm running about the same ECT that I was before. It is strange, but I guess I'm attributing that to the EGR delete. The truck doesn't have any problem getting up to running temp, either.

One more thing, I did notice on the tstat (both old and new) it had something like 174* stamped on it, which would make sense considering my running temps.

[Dante04SRT]

Originally Posted by colo_dually

With the deletion of the EGR Cooler, you are safer however there can still be an issue.

That issue is this, and from what I have seen/read it doesn't happen often. You have coolant flowing at X rate with a clear cooler. Once that cooler starts to clog you begin building additional pressure in your oil cooler. That pressure can cause a rupture internally to the oil cooler. Now you have either a coolant in oil, or an oil in coolant situtation. Both of which will cause damage.

The 15* delta is paramount on a stock EGR cooler. As an indication that there is such a restriction in coolant, which causes the EGR cooler to overheat and fail internally.

That's my understanding, anyway.

I did consider the additional pressure issue; Just haven't figured a way to calculate the point at which the pressure would damage it (ie, at say 10* temp delta, what is the additional pressure put on the cooler?).

The delta being 15+ doesn't hurt your engine as long as your temps are within range. The high delta is simply a warning of eminent failure of the coolers resulting in many issues, including coolant in your oil. I Have a BulletProof EGR cooler & external oil cooler. After I first installed them I test drove and had deltas higher than what I understood were safe, oil temps being cooler than ECT. Turns out, with help from the ORG, that deltas mean nothing to me because of my external oil cooler as long as all my temps are w/in range.

The deltas only indicate how well your stock style system is working..or not!

What're you doin up so late?

I think ultimately I'd LOVE to go with an external cooler. I still can't figure out why these 6.0s came with this problematic oil cooler design anyway. I mean, most every vehicle that has an oil cooler simply runs an air/oil radiator style cooler!

I guess as long as my ECT/EOT is within acceptable range, I should be ok, understanding at some point when the delta becomes too high, I may be at risk of an oil cooler rupture.

....and I've still got to get to the root of my ECT being so low.

[Geoff941]

Originally Posted by colo_dually
With the deletion of the EGR Cooler, you are safer however there can still be an issue.

The 15* delta is paramount on a stock EGR cooler. As an indication that there is such a restriction in coolant, which causes the EGR cooler to overheat and fail internally.

If you delete the EGR cooler, how can the EGR cooler fail?

[Fishermedic]

^^^^^^ I think you need to add to your highlighted text.

Originally Posted by colo_dually

With the deletion of the EGR Cooler, you are safer however there can still be an issue.

That issue is this, and from what I have seen/read it doesn't happen often. You have coolant flowing at X rate with a clear cooler. Once that cooler starts to clog you begin building additional pressure in your oil cooler. That pressure can cause a rupture internally to the oil cooler. Now you have either a coolant in oil, or an oil in coolant situtation. Both of which will cause damage.

The 15* delta is paramount on a stock EGR cooler. As an indication that there is such a restriction in coolant, which causes the EGR cooler to overheat and fail internally.

That's my understanding, anyway.

With the stock EGR it's a problem but not so much with the delete as in this case. The problem could be the oil cooler.

[RodeoPapaStroker]

Originally Posted by Dante04SRT

Since getting my gauges installed, I've noticed about an 8-10* delta between my oil & water temp. I have done the complete swap and ELC swap but unfortunately didn't have the extra gauges beforehand, so I have no idea if it changed at all...

That being said, I began to think about why the delta matters. If I understand the logic correctly, if the oil temp is more than 15* warmer than the coolant temp, it means that the coolant passages in the oil cooler are somewhat clogged and restricting coolant flow. In my case, my ECT is around 180-184* and my oil temps never exceed 190-195*. NOW - In thinking further - Aside from the coolant hitting a bottleneck, the cooler is still working well enough as the oil temps are still well within acceptable levels. Isn't that the main concern?

I'm trying to think of the harm of a large delta (15*-25*)... Even if my EOT reached 20*, my ECT would most likely still be say 180* and my EOT would be 200*. Both of those numbers independently still sound pretty good.

Realizing of course that a high delta means that the cooler isn't as efficient as it SHOULD BE, but in the case of oil potentially only being 200-205*, where is the harm? I don't have the EGR system anymore and assuming my temps are both in fine shape, I don't think I'm at risk of engine damage, right? I mean, if its the coolant side of the oil cooler that gets clogged, but the ECT is still consistently low, what harm is there? This would also suggest that the oil side of the oil cooler is flowing just fine, so it's not like a blockage is there to prevent the oil from flowing at a high enough rate to keep the bearings safe.

It's really late here so I hope I've articulated the point I'm trying to make well enough. Basically, even if your ECT/EOT delta is high; what is the overall harm being done if both temps are still within spec and the emissions systems have been deleted?

First of all, why is your ECT only 180-184? Should be 188 and up.

And second, as many of us have learned, in a PSD "well enough" is not good enough.

Third, if your cooler isn't working as efficiently as it "SHOULD BE" you will have a failure, possibly causing further damage.