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Even if a hotter running T-stat was able to lower the temp differential between ECT and EOT it is not really solving the initial problem. This is only masking the fact that the cooler may be working less efficient than intended. In my mind raising the coolant temp to get a lower differential is only masking the issue at hand.
Since the Ford spec is a 15 degree difference, unofficially may be 7 or 8, based on a 192 degree T-stat then maybe we need a new set of numbers for a 200 degree T-stat. If the efficiency changes with the ECT then we can not use the differential for 192 at 200. If the effiency changes then the measurement of how efficient it is must change as well.
My logic may be completely off base but it seems logical to me, LOL.
The official test is done with an ECT of no less than 190 degrees. If you have 189 or less ECT any testing is invalid.
As for "official" tests It was originally 25 degrees difference normal driving, then 15 degrees WOT to 49 mph then to now it is 10 degrees @ 1800 rpm driving 15 minutes.
Service Manual Procedure:
NOTE: Verify that no accessories are in use (engine block or oil heaters).
Clear all the DTCs.
Cold soak the vehicle at ambient temperature for a minimum of 10 hours.
Ignition ON, engine OFF.
Access the PCM and monitor the ECT (TEMP) PID.
Access the PCM and monitor the EOT (TEMP) PID.
Access the PCM and monitor the RPM (RPM) PID.
Access the PCM and monitor the MFDES (MASS) PID.
Record the ECT and EOT sensor temperature values.
Drive the vehicle at an engine speed greater than 1,800 RPM and 15 mg/stroke MFDES for at least 15 minutes. Select the appropriate gear to achieve the operating conditions.
Does the ECT PID and EOT PID temperature values change by a minimum of 6ºC (10ºF) from when the ignition ON, engine OFF valves were recorded?
IF Yes
INSTALL a new oil cooler kit.
IF NO
INSTALL a new ECT sensor or EOT sensor in question.
CLEAR the DTCs. REPEAT the self-test.
In a nutshell 1800 rpm is basically 65 mph for most trucks.
This thread is bringing up a lot of good points and views. However, I'd like to back it up for a minute and raise a question and get some more opinions and thoughts . What exactly are we trying to prevent by keeping the EOT within 15 degrees (or 10) of the coolant temperature? Just from what I have learned from you guys we are trying to prevent the EGR cooler from running too hot from a lack of coolant flow through the oil cooler then to the EGR cooler. In addition, we are making sure that the EOT doesn't go above the severe service temp and damage parts within the engine, or degas at 253 degrees. Now this is just a question not a diagnosis, but if the difference between my ECT and EOT has been at around 12-13 degrees for 3 years since I got my gauges and hasn't increased, and my EOT doesn't get near the severe service level unless I'm towing 13k pounds in 105 summer temps, would it be safe that my oil cooler is operating at an acceptable level? I say this because when I bought the truck it needed an oil cooler. I knew this because it was losing coolant through the EGR cooler. So I had it all fixed when I bought it. So unless the EGR cooler starts leaking coolant out is there any other damage being done by running a 13 degree difference between ECT and EOT?
This thread is bringing up a lot of good points and views. However, I'd like to back it up for a minute and raise a question and get some more opinions and thoughts . What exactly are we trying to prevent by keeping the EOT within 15 degrees (or 10) of the coolant temperature? Just from what I have learned from you guys we are trying to prevent the EGR cooler from running too hot from a lack of coolant flow through the oil cooler then to the EGR cooler. In addition, we are making sure that the EOT doesn't go above the severe service temp and damage parts within the engine, or degas at 253 degrees. Now this is just a question not a diagnosis, but if the difference between my ECT and EOT has been at around 12-13 degrees for 3 years since I got my gauges and hasn't increased, and my EOT doesn't get near the severe service level unless I'm towing 13k pounds in 105 summer temps, would it be safe that my oil cooler is operating at an acceptable level? I say this because when I bought the truck it needed an oil cooler. I knew this because it was losing coolant through the EGR cooler. So I had it all fixed when I bought it. So unless the EGR cooler starts leaking coolant out is there any other damage being done by running a 13 degree difference between ECT and EOT?
Once a delete has been done the 15 degree split is irrelevant
You are pretty much right with the EGR coolers ability to rupture with the lack of coolant flow.
With the ERG cooler deleted, you still don't want a large difference between the coolant and oil temps because of the possibility of rupturing the oil cooler.
I went out this morning and did a run up I35 to see what is going on with the ECT and EOT. I ran about 26 minutes and turned around and came back. Here are some pics of my gauges after I stopped when I got off the interstate and stopped after a few miles of city driving. Outside temp was 24. The only time my ECT got above 180 was when I turned around and ran it to 28psi boost merging back on I35. It went to 185 but cooled right back down. My EOT was always right around 13 degrees warmer, or about 192. You can see the total trip was 1hr 3 minutes and about 53 miles. Forgot to add, 16.3mpg.
Drive the vehicle at an engine speed greater than 1,800 RPM and 15 mg/stroke MFDES for at least 15 minutes. Select the appropriate gear to achieve the operating conditions.
In a nutshell 1800 rpm is basically 65 mph for most trucks.
Josh[/QUOTE]
I haven't been paying attention to the rpm. I did an equation I found and it turns out to be about 58 mph for my truck. I guess I should retest at 1800 rpm.
1) Judging by your EGR Error % you're valve is starting to stick.
2) You need a t-stat
Another point from your comment about max oil temp. Are you getting close to the upper limit while towing?
Josh
1) I agree. It has never been changed.
2) Yes as soon as it gets warm enough to work on it.
From the original post in this thread from last summer.
"EOT--At regular cruising speed it runs around 230-232 which is 20 degrees above the ECT. When the fan comes on at ECT of 210, it cools down a few degrees, then returns to 230-232. On the 3 grades it went up once to 247 and once to 240, then cooled right down with the ECT when the fan kicked in to 2500."
I was running it about 65 mph. If I run 60 MPH, which is where I should be anyway, it runs a little cooler. On the grade when it hit 247, I didn't let off until I got to the crest so I'm not surprised. It was a long mountain climb. After that I backed out of it and ran it a little easier I didn't see those temps again. Mostly just EOT 230, ECT 210.
This thread is bringing up a lot of good points and views. However, I'd like to back it up for a minute and raise a question and get some more opinions and thoughts . What exactly are we trying to prevent by keeping the EOT within 15 degrees (or 10) of the coolant temperature? Just from what I have learned from you guys we are trying to prevent the EGR cooler from running too hot from a lack of coolant flow through the oil cooler then to the EGR cooler. In addition, we are making sure that the EOT doesn't go above the severe service temp and damage parts within the engine, or degas at 253 degrees. Now this is just a question not a diagnosis, but if the difference between my ECT and EOT has been at around 12-13 degrees for 3 years since I got my gauges and hasn't increased, and my EOT doesn't get near the severe service level unless I'm towing 13k pounds in 105 summer temps, would it be safe that my oil cooler is operating at an acceptable level? I say this because when I bought the truck it needed an oil cooler. I knew this because it was losing coolant through the EGR cooler. So I had it all fixed when I bought it. So unless the EGR cooler starts leaking coolant out is there any other damage being done by running a 13 degree difference between ECT and EOT?
My opinion is; probably only a handful of people know how that 15° number was decided but whether it was exhaustive testing by guys in lab coats, calculated by a guy with a sliderule and a bunch of data from the dealerships, or they walked down the hall and asked Bob what he thought, they would have tried to be conservative in order to cover their butts. The origonal issue was likely not recognizing the significance of the tiny passages in the oil cooler. The surface area requirements were calculated, the part was built and it worked fine. No consideration of it becoming a filter.
I think if it's not rising, your oil cooler has got some life left in it and you're OK. Who knows for how long, just one more season or ten years. I changed coolers a couple years ago and went with the BDP egr cooler and OEM oil cooler. Temp spread was at 4-6° when I put it back together and it's still there now. It climbs very little towing. While these numbers can vary from one truck to the next, it does make it seem the overall design isn't an issue if everything is in good condition.
I agree with Josh, if the EGR cooler isn't installed it can't leak but I know me and if I would have done a delete, I would have gotten tired of the CEL pretty quick and bought a tuner, driven it too hard, and have head studs by now-lol.
I agree Rusty. If I wasn't monitoring the temps all the time and being involved in this site it may spell trouble. I won't dispute anyone who says my oil cooler is clogged to some degree, and may be on its way out. But as long as it doesn't get worse, more that the 13 or so degrees I see now, and I'm not having any other issues like losing coolant or puking, I think I will keep running it. At this point I'm starting to think about a new truck with a heavier payload and more towing capacity rather than investing in the old rig.
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