High EOT's AFTER repairs.
 

Hello all,

I'm in head scratching mode and need any and all input to find a solution to my problem:

The truck is a 2006 (September 26, 2005 build date) with the 6.0 liter diesel, auto trans and 4 wheel drive. The mileage stands at 139,500 now and was about 133,000 at the time of the head gasket failure.

I blew a head gasket on September 20, 2012 while towing one Polaris RZR (1,100 lbs) and one Jeep CJ-8 (5,300 lbs) on a 30 foot equipment trailer (I’m guessing 3,000 lbs). As the coolant level dropped I refilled the system with water (this becomes VERY important later). I took the flattest route I could find after the wheelin’ was over and had to add very little water.

I drove the truck for nearly 3.5 months in this condition…as long as it wasn’t loaded I never lost coolant (water). The EOT and ECT stayed within 8* of one another for a couple of months. I decided to go ahead with the repairs when my engine oil temp (235* oil temp with 190* coolant temp– truck unloaded) started to climb due to the rust in the cooling system as a result of not having refilled the system with the proper coolant.


I took the truck to a quality repair shop on January 1, 2013.

The following items were upgraded or repaired:

1. New heads - aftermarket.

2. New Ford head gaskets.

3. ARP head studs.

4. New Ford oil cooler.

5. New Ford HPOP.

6. Sinister Diesel coolant filtration system.

7. All related gaskets - Ford.

8. Fuel pressure regulator (it idled poorly) – Ford.

9. Oil temp sending unit after the oil heating problem was discovered - Ford.


The following items had been upgraded or repaired PRIOR to the head gasket failure:

1. EGR cooler delete by Sinister.

2. HPOP high pressure line connector.

3. Fuel injector interconnects and o-rings – pardon the layman jargon…I don’t know the appropriate acronym.

4. Waterpump – Ford.

5. BullyDog GT tuner – in “Tow” mode 99% - in “Performance” mode the other 1%...I’m afraid of “Extreme”.

6. Remanufactured 5R110 from Ford with every available upgrade from Ford and a new trans cooler.


We learned some interesting things…

1. We should have flushed the system BEFORE teardown.

2. It would appear that my engine was replaced before I bought the truck. It should have an “18mm” engine but has a “20mm” instead.

3. Clearwater Cylinder Head Exchange will tell you repeatedly what they’re going to do and then not do it and then act like you’re being a jerk for being upset with them.


Phase 1:

1. Lift the cab.

2. Teardown.

3. Rinse block and radiator while apart.

4. Reassembly with parts listed above.

5. Restart and discover poor idle and engine oil temp issue (215* unloaded oil temp, 170*unloaded coolant temp).

6. Replace bad thermostat (engine would not come up to operating temp).


Phase 2:

1. Discuss issue and decide that the NEW oil cooler is plugged.

2. Flush cooling system per Ford’s instructions using VC-9 – FYI…it’s $26.50 per quart…2 are required…just sayin’.

3. R&R oil cooler – new Ford part installed.

4. Test and find idle issue resolved but that the oil heating problem persists (250*oil temp and 190* coolant temp – towing the CJ-8 on a 2,500 lb trailer).


Phase 3:

1. Discuss issue and decide to cut the old cooler and new cooler #1 in half with a bandsaw.

2. We found the old cooler to be blocked 50% or more…we found NO blockage in new cooler #1.

3. Scratch heads repeatedly…


Phase 4:

1. Seek counseling to cure odd eye twitch and drooling.

2. Drink a lot.

3. Call for backup.

4. We did a flow test on a known good 6 Liter to compare to mine. We disconnected the line that interconnects the intake manifold and degas bottle and filled a 16 oz bottle. The time to fill was essentially the same. Based on our research, if we’re getting coolant from that hose the coolant MUST be flowing thru the cooler.

5. Further research on the engine found the drain back valve at the base of the oil filter (allows the oil filter housing to drain prior to completely removing it to prevent a mess) was missing…how you ask? We have no idea…it has since been installed with no effect on oil temps.

6. Scratch head repeatedly…

7. Drink…a lot.

What do the EOT/ECT sensors read after an over night soak? Have you tried swapping temp sensors between these two? I see the EGR delete, is the EGR valve still plugged in? not sure if it is possible to swap the connectors between the ECT/EOT and see if the problem follows where the connector is plugged in.

mustang_309

We check the temp readings each morning before start and they are within 1 degree of each other and within a degree or two of ambient.

We took an EOT sensor known to be good from another truck and find the readings on the donor truck to be the same as before and the readings on my truck to be the same as before.

We considered the EOT/ECT connector swap but the sensors are too far apart.

I believe the EGR valve was deleted as well and the Bullydog Tuner handled the check engine light.

Thanks for the input...keep it comin'!

Have you removed the BD tuner just to see what happens? Might be worth a try.

Wait4it,

We have monitored temps with both the shop's scanner and the BD Tuner...the readings are within a degree of one another. It should be noted that the tuner must be disconnected to use the scanner. We have double-checked that the tuner was in "no power" mode before we disconnected it.

Thanks for your time and please forward any and all thoughts...somebody out there is going to think of the one thing we haven't considered.

06FUN

Just making an educated guess here, as I see you have verified water flow to the oil cooler. Is there a way to verify oil flow to the cooler, does it come from the turbo drain and block. Cooling in the oil cooler takes two things, water that is cooled, oil that is hot. So I am just wondering if there is a way to inline temp check, and verify flow from the input of oil to cooler. Also, I don't know this to be true I have never been that deep into the top of my 6.0 but is there a bypass of oil at colder temps and routing to cooler at hotter temps or does the oil always run and cooling is affected by thermostat control of water and oil and water sensor temps. I am also wondering if the above is not true if you have a collapsed oil hose somewhere restricting oil flow. Maybe a tech can chime in and help with a troubleshooting phase. Wow you have spent a lot of money. I would be drinking heavy too!

Not that I have any useful information to add, since you appeared to have attempted to address this issue vigorously since repair. But here are my questions. Have you tried removing the coolant filtration system out of the loop and returned back to factory setup to see if oil temps change? Have you removed the coolant filter and cut in half for inspection yet? If so, what does it look like? Throughout all of this, has the fan clutch ever cycled on at any time? The reason I ask this is because 250*F is definitely getting into some territory where I would be concerned? Is the oil really getting THAT hot as in, have you verified with an alternate method (ie infrared gun)? Sorry for more questions than answers.

By the way, I really like the fact that you typed your post using flawless English grammar, and including just about every relevant little piece of information you could to help us, help YOU.

Yes, THANK YOU! I'm getting really tired of trying to decipher the garbage people write in their posts. Best of luck with your diagnostics. I'm going to guess that maybe your LPOP is going south and you're oil flow isn't what it should be. I'd get an oil pressure gauge installed in the test port and see what kind of pressure you have.

The Coolant flow test is Hard to do Iv never saw anything about it. Its good you had flow but Is it Enough???

The reason I mention this is you said you added water and drove like that for a few months. SO that said since the Coolant Mix probably wasnt a 50/50 water-coolant mix you could have Cavitated the Front cover where the water pump sits and the water pump isnt flowing properly

I would Also Verify the EOT Sensor circuit for wire chaff/short this could alter the reading of the EOT sensor no matter what scanner is used to look at temps

Just a shot in the Dark ^^as a bad wire should/could alter the EOT Cold Soak reading But your cold readings are good from what you saying

There is a bypass in the system to prevent failure in the event the oil side of the oil cooler plugs...we'll be checking that today.

We have blocked the coolant filtration system with no improvement.

We dumped the contents of the filter in a bottle...nasty but not unexpected...even after the flush between new cooler #1 and new cooler #2.

We have taken temps at various places on the engine with infrared...and the temps are comparable to a known good engine's temps.

I'm going to look into the fan...it did seem to cycle on at odd times. Do you know if oil temp affects the turn on point of the fan or is it just ECT?

Thanks for the kind words on my original post...

I'll talk with my tech today on the low pressure check.

We intend to do a one gallon test today...we only did a 16 oz test the first time...There was a spread between the two trucks and we want to confirm our findings with a bit more structured test...I'll report when I know.

I see your point on the damage to the front cover...but the ECT is holding so steady I hadn't considered it.

We've talked about extending the harness for the EOT and ECT so we can switch them...just to see if we get a funky reading on the ECT side...

I'm making notes of your responses to pass on to my tech in a couple of hours...

Thanks for your thoughts and I'll let you know what we learn.

And by the way...For Sale...

To test the fan clutch, you would need access to a scan tool that can not only read live data, but can also take active command of some of the parameters as well. The IDS which is what I use can do this. I don't know about the aftermarket scan tools. And the way to do this, is to select RPM, FAN_SS RPM, FAN_VAR on your scan tool. Raise engine RPM to 2500 RPMs steady, take active command of FAN_VAR and switch the duty cycle from 0% to 100% while monitoring FAN_SS RPM. FAN_SS RPM should switch from less than engine RPMs to over 2800 RPMs rather quickly and accompanied by the loud "jet plane" type sound to indicate it's functioning.

And to your question regarding EOT, YES it does affect cooling fan operation. I say this with 100% certainty is because on a couple of trucks I've had apart that I had forgotten to re-connect the EOT sensor, the fan clutch was coming on a lot earlier than usual but EOT readings weren't out of range. The point I'm making is, even with the EOT sensor disconnected, you will still see temperature readings (and I'm guessing the same will be true for ECT as well).

... which is also why I was more receptive to chiming in to your thread with what I could offer. At least I could fully understand your issue, and every last little detail you included, which I can't say the same for other threads I've had to read through.