I though he was a bit cool on the ect too but his first post said it's running 188-190, a new Tstat will bump him up to 192-194 and that ain't gonna help 246* oil temps
There's more to ECT/EOT delta spread than "it's a clogged oil cooler". This is why I posted to get a tstat done first.
A) It's WAY cheaper....even at dealership prices over swapping an oil cooler that just might be
working correctly where the coolant system is the problem.
2) His ECT numbers of 188-190 show a HUGE problem.....Where as the EOT numbers are a mute point until the coolant system is functioning correctly.
First off the Tstat controls the overall function of the coolant temp, along with the coolant pump it also controls the coolant flow path.
With the tstat closed the coolant pump circulates the coolant thru the flow path....(i.e. the oil cooler). When the coolant reaches temps the tstat will start to open at the set temp (i.e. 190*). Why?? Cause the coolant system needs to flow into the radiator to transfer heat off the coolant...after which time the now lower coolant temp causes the tstat to close. Then as the cycle goes again....second verse the same as the first. SO one should always see the ECT ranging between 190-199* (driving conditions dependent).
This tells you the tstat is working and the coolant is flowing properly being effective
in it's J.O.B..."absorbing heat and transferring it to the outside air via the radiator."
IF the tstat fails....and they sure do.....what happens???? The tstat should fail OPEN.
Why??? This should prevent any significant issues as coolant flow is CONTINUOUS to the radiator along it's path thru the motor.
Okay...why is that "bad"???
CAUSE the coolant is now NOT being as efficient at the
"absorption" of heat (effective heat transfer) from the oil that circulates thru the oil cooler. So your coolant is running wide open thru the oil cooler straight to the radiator...hence the oil cannot transfer the heat at the same rate of flow as the coolant is flowing thru the oil cooler.
How would you know???.....High EOT with a low ECT readings. Shown where ECT is NOT operating in the normal range which is OVER it's lower opening limit of 190*F.
So the the OP.....unless you see ECT ranging thru 190-199* (or thereabouts) you have a tstat problem....not an oil cooler problem. Once you control the coolant flow correctly THEN you should see the coolant doing it's J.O.B....collecting heat from the passages of the oil cooler....which just so happens to LOWER overall EOTs......who would have guessed.
IF by some chance your ECTs are already or start ranging correctly and your EOT delta exceeds the accepted "6.0 ECT/EOT delta" (I recall that to be more like a 15* delta) then by all means replace your oil cooler.
At the end a system functioning properly should show ECT ranging 190-199*, and EOT generally holds a pretty steady 2-5* range that follows the ECT temps. As ECT drops....EOT will hold for a bit...then drop a little (ranging 2-5*). Now the 190* coolant is circulating thru the motor collecting heat....rising to say 199* as the tstat is now full Open flowing thru the radiator as well as the other flow paths (i.e. the oil cooler)....EOT will tend to creep up a tad (ranging 2-5*)....then start dropping as the coolant exits the radiator.......it's a cycle.