Except that's not what he said. What he said is that by changing the parameters of the engines operating window, you can't strictly go by what Ford originally specified as an indicator of poor oil cooler efficiency. Using your example...if your coolant is at 190 and oil is at 206 in the conditions Ford says to test, that indicates a greatly reduced efficiency in your oil cooler. If you change to the 200* stat and now your values are at 202 and 212, did you unclog your oil cooler...simply by changing the stat?

 

Whats being said makes logical sense. Increasing the operating temp does not unclog a clogged or partially clogged oil cooler. Its still in the same state it was prior

So truly your deltas aren't actually getting "better" it just appears that way. It it a curious subject though. If your theory is correct TooManyToys, that as coolant temp is increased the spread between it and oil temp will need to diminish, then eventually at a certain coolant temp the spread would have to be 1°< to maintain that same plot or true accuracy of the test

 

my 550 runs a little cool, so I was going to change the thermostat out, among a slew of other things.

I've read quite a few of the pages in the 75 page long thread but didn't notice if it said these were good choices for warmer climates. Would the mishimoto 200deg one still be a good choice even if I live in the sunshine state?

Already in the 90s here, N. Central FL.

 

the stat dont care if its 10 or 90 outside,still opens and closes at predetermined rates

 

just wanted to verify since they state it's good for those in colder climates, which I am not

 

I live in Tennessee, tow a 13k lbs fifth wheel and took my mishi stat out. Mine would consistently run 204-206, but while towing, the fan would come on almost all the time because it would start to see 208 going up hills. With a new factory stat, I see 190-192 in the summer and tow less than 200, so the fan doesn't come on until big climbs up hills (like it should).


I really wish they would make one that is a 192 or 195 for those of use that tow a lot in warm climates. I like how quick the mishi would warm up and it would operate in a closer range, but it was just too high for towing.

 

How cool is "a little cool"?

I'm planning to leave my 200* stat in for the summer. Gets up in the 100's sometimes in VA, will see what temps are and if I plan to keep it in all summer.

 

I leave mine in, when towing I am usually at 206, when unloaded 200-202 even at 90 degrees.

 

Again, I'm not a physicist...I didn't even stay at a Holiday Inn last night. I do know that with my old OEM stat I ran188/190 fwt 197/198 eot....with the mishi it's 200/202 fwt 206/207 eot with an occasional 208. Now either my sensors have coincidentally gone wacko at the same time I put in the mishi or the deltas are closer than they were without it....either way neither are are nearly hot enough to concern me. When I towed my 34'T/T the temps ran 202/204fwt...212/214eot still no concern here.

....the ambient when I towed the T/T was 75* or there abouts, I live in Me. and that's about average for highs other than the rare 80's

 

I'll try to explain better than I did before...no one is doubting that your temp spread is smaller than it was before, or that temps that are being reported are too high. At least not that I've seen in any post. What has been said is that now that you have changed the operating temp parameter for the engine the Ford specified 15* delta at a certain temp and speed guideline for determining oil cooler efficiency is no longer 100% valid.

 

Not sure what's funnier:

1) Continuing to incorrectly use the term "Delta"
2) Continuing to use the outdated 15 degree temp spread.

Josh

 

I use it because everyone else seems to...plus even though it is technically incorrect, it sounds way more badass than "difference"

So, what is your non-outdated spread info? And what's it based on?

 

LOL, gotta love the newbs...

Ford Service 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.


Josh

 

I'm thinking either something is left out or incorrectly worded...because it's saying that if I drive for 15 minutes under those conditions and my ECT and EOT values go up by at least 10* from the cold soak temps then I need a new oil cooler? Is it supposed to say the difference between the ECT/EOT values?

I knew my oil cooler was clogged as soon as I got gauges for my truck...when starting ECT and EOT would be within two degrees. When driving around my ECT could be up to almost 40* higher than my EOT until the coolant got to 180. Then the oil would start catching up. On my first highway drive the oil then kept on going to 30* higher than the coolant.

 

It's usually around 188-190, i've almost never seen it go above 190. I've been suspect of a failed thermostat since I put the scangauge on it.