Well, I haven't been here in a long time. The truck has been just terrific, mostly used for towing our travel trailer. Earlier this year i developed a leak and lost 3 quarts of oil before I caught it. I would think with 15 quarts in her this shouldn't have been too big a deal. However, I am now experiencing 10-15 degree swings between ECT and EOT. Before I give the particulars, yes, I have had three new thermostats, two Ford and one brand X. Anyway, coolant temps are 184-200 depending upon load, terrain, etc. At the same time, oil temps run 205-230. There is no oil cooler to get plugged up. Anyone have an ideas? She's got 120K on the clock, doesn't burn oil, no disappearing coolant. I am concerned about blowiing a head gasket or other serious damage at these temps, but don't have a clue where to start? Yes, the fan does come on and help, but still this seems plenty hot. Thanks, gm.

 

Difference between coolant and oil tempature not exceeding 15F while pulling hard isn't something to worry over if fan come's on to bring it down. Your numbers say max of 200 coolant and maz of 230 oil,that is 30 deg difference and is something to worry about. You also say "There is no oil cooler to get plugged up." There is an oil cooler unless you removed it. How are you reading the temps?

 

Oil temp can hit 230 pretty easy while towing, but your saying you dont have an oil cooler?? What happened to it? If your oil cooler was still on the truck, then we can talk about the delta temps.

 

Okay, my bad. Yes, there is an oil cooler, I was speaking of the EGR cooler. Sorry. I get that temps can go up but in 13 years of ownership it has never, never been above 224-225 even towing over the continental divide with my 10K# trailer behind. Yes, 5 degrees is probably no big deal, but there should be a reason for it? I'm just not ready for a tear down and studs...

 

Oil temp won't blow head gaskets but coolant temp will. I'm chasing the same thing with coolant temps pushing 230 and EOT 247. I'm BPD every thing but there fan. Flushing as we speak. Changing thermostatic and wp. But I don't think that's the problem for what I can see. I don't think BPD makes a big enough oil to air cooler period. My sons 5th wheel is 40 foot, and clocks in at 16K. With out the trailer all is fine and eot is lower most the time then ect.

 

Howdy,

Take it out on the freeway (empty) and run it at 65mph on the flat.

If it exceeds 15 degrees EOT vs ECT, your oil cooler may be clogged or becoming clogged..

If it doesn't, then you don't have a problem (with the oil cooler)

But, that "test" may not be fully valid if you are not using an OEM T-stat (of the correct temp rating)

 

The 15-degree delta is a qualitative measure of how much restriction the oil cooler provides to the EGR cooler. If you have no EGR cooler Delta is completely and entirely irrelevant. Your only concern with oil temperature is how much heat before the system starts breaking down that's somewhere around an EOT of 250 plus degrees. An older truck your radiator and other coolers are probably getting plugged in with bugs and dirt and need to be washed out thoroughly

 

Yeah, you're right. I was just being lazy. Time for new oil cooler, coolant flush, radiator cleaning, maybe even treat her to a new water pump, what the heck. Thanks, everyone. I'll make the change and report back. Have a terrific evening, gm.

 

I tend to disagree.

The oil cooler is there to cool the oil. (period) ....... the oil gets very hot because it's being used in a(n) (up to) 4000PSI hydraulic system to operate a HEUI injection system. If it gets too hot, the ECM will will react whether there's an EGR cooler or not.

The FOMOCO SB that details the 65mph 15 degree test.

I couldn't find the SB that describes it but the following thread (last post) outlines it.
https://www.ford-trucks.com/forums/1...ct-spread.html

Regards,


Rick

 

That test evaluates the oil cooler as a restriction of water flow through the egr cooler,BECAUSE a restricted oil cooler will result in flash boiling of coolant in the egr cooler
Flash boiling will produce PUKING at the coolant reservoir.(which eventually will lead to 100% chance of egr cooler rupture)(THAT IS THE ONLY THING THIS TEST IS EVALUATING)actual oil temperature that Ford considers excessive is over 250 degrees where the engine derates. That test is ONLY VALID when done on level groundfor several miles at 65 mph. IT HAS ABSOLUTELY NOTHING TO DO WITH THE MAXIMUM ALLOWABLE OIL TEMPERATURE WHEN PULLING A TRAILER UNDER ANY CONDITIONS. As long as oil temperature stabilizes under 245 YOU ARE NOT OVERHEATING! Go ask a real mechanic. The semi I drove cruises without a trailer at 235 even in winter, and is 100% normal.

 

Further to that I will say that in my opinion every case where Ford did the head gaskets twice due to puking there was probably nothing wrong with the heads at any time the whole puking was caused by flash boiling because the EGR cooler was very nearly about to die. The puking problem would come back and everybody just blame the mechanic or the heads and said that the mechanic hadn't done a good job. I drove up into Northern Canada this summer pulling a camper at times on Hills my Delta was well over 30 degrees my oil temperatures were as high as 238, my coolant level is actually full to the original mark on the bottle or a whisker higher and I experienced zero puking because my engine does not have an EGR cooler to flashboil, it has been removed

 

First, do the standard 65-mph flat and unloaded highway drive to verify your coolant gets to/above 190 and observe what your OIL temp rises to. Most folks will drive for 20 minutes AFTER coolant reaches 190 to ensure a complete heat soak of the engine, this is where the 15 degree difference matter.
This is the baseline to determine oil cooler health.

Assuming, your temps are within 15*, the next step is to verify the oil bypass in the base of the oil filter housing is working properly. This is an infrequent failure part - I believe it CAN be damaged by improperly installing a new oil filter.
Did you happen to replace your oil filter around the time this problem started!?!?

The oil pressure bypass opens when it senses too large a pressure pushing the oil through the oil cooler. The problem with this bypass when it fails, is that it prevents proper cooling of the oil AND prevents proper FILTERING of the oil also.

Lastly, monitor your radiator fan. When the temps get high you should be able to hear it roaring under your hood. Check that it's actually turning at idle, is your A/C working properly when you are stationary (another verification of the fan operation)

Good luck!

 

The oil pressure bypass opens when it senses too large a pressure pushing the oil through the oil cooler. The problem with this bypass when it fails, is that it prevents proper cooling of the oil AND prevents proper FILTERING of the oil also.



This is only partially true. The oil cooler restriction being discussed is on the coolant side not the oil side. You could totally plug the coolant side of the oil cooler and it wouldn't affect oil pressure anywhere in the system in the slightest waye.

 

Absolutely right.

And you're claiming that a restricted oil cooler will not result in high(er) oil temperature?

If that "Real Mechanic" doesn't expect higher oil temperature DUE to a (coolant-side) restricted or plugged oil cooler, I am finding different "Real Mechanic"

 

Of course it will increase oil temp but as long as it stabilizes well under derate temp under full load......who cares if it's 5 or 10 degrees hotter than someone else's truck. (Sure it's not perfect but as long as it's somewhere in the "green"zone remember it isn't quite new anymore) just a thought Amsoil touts testing their oil to 300 degrees for 100 hours SAFELY. Anyone that thinks 240 to 250 climbing a hill is instant death is just silly