2006 F150 5.4 Towing Difficulty

[Al and Missy]

We recently had an overheat situation with our F150. We were pulling the 8 mile 6% grade up to the Blue Ridge Parkway westbound on US 421 towing our 2001 Safari 25. While I do not have weight data as loaded, based on previous weights I'm certain that the trailer was under its GVWR of 6300#. The truck was probably about 100 -150# over its payload capacity, but the GCVW should have been under the GCVWR. Per the owner's manual the Max Tow is 8600#. Deducting the truck payload of around 500#, that still leaves 8100# for a trailer around 6300#.

As we climbed up, temperatures rose and speed dropped. The truck is a 2006 F-150 Lariat 4x4 with the 5.4 V8, automatic transmission and a 3.73 limited slip differential, running Shell regular gasoline. I have the Edge Evolution tuner installed and running in Tow mode. I have the display set to show cylinder head temperature, oil temperature, and transmission fluid temperature. I figured the engine temperature gauge on the dash would be sufficient for water temperature.

About 1 mile from the top, cylinder head, oil, and transmission fluid temperature reached around 230 degrees but the dashboard engine temperature remained on the center mark. I heard a metallic pulsating noise that sounded like a belt flapping around hitting stuff under the hood. I pulled over and checked under the hood and, aside from smelling hot, everything seemed normal. We sat for a while and let the temperatures subside to about 220 and then did the last mile.

I don't understand how the truck overheated with the temperature gauge right in the middle of normal. It hardly moved from its normal position. It acts normal when the engine is warming up. My guess is that the noise was coolant spot boiling on the head or fuel detonation due to the high cylinder head temperature.

Does anyone have any ideas as to what the noise was? IS there anything I could have done with driving technique to minimize the overheating?

Thanks,

Al

[ggoat!!!]

It's common knowledge that the Ford dash lights (and other makes) are glorified idiot lights. On my Chevrolet SSR, the dash temp gauge stays on 210 when the actual temperature can vary from 185 to 230; and only then, it MIGHT move 1/32 of an inch. I've been as hot as 238 climbing McClure Pass in the summer heat of Colorado (a long 9% pull) and my dash gauge never really moved; I relied on an app called "Torque" on my android phone using a bluetooth OBDII connector.

Don't rely on the dash gauges for anything...

BTW...230 isn't high for coolant or oil temperatures, but it IS getting warm for an automatic transmission. You won't boil coolant at 230 unless you have a leak in the system or don't have a sufficient coolant to water ratio in your cooling system.

[Al and Missy]

Thanks for the data. I now have my Edge Evolution displaying all temperatures, cylinder head, oil, transmission, and coolant. I'll keep an eye on it. Water should not be hotter than cylinder head or oil, and the coolant ratio should be good, but i'm assuming the dealer filled it properly when they changed the coolant 5-10k miles back.

The 1/4 tick on the gauge corresponds to about 150, and the center tick is around 190. But maybe it sticks there. If it were linear the 230 that i saw should have been reading around the 3/4 tick, but it didn't budge off the center when all the other temps were 230.

[jcl]

Originally Posted by Al and Missy

The 1/4 tick on the gauge corresponds to about 150, and the center tick is around 190. But maybe it sticks there. If it were linear the 230 that i saw should have been reading around the 3/4 tick, but it didn't budge off the center when all the other temps were 230.

I don't know specifically about your vehicle, but on my last four (non-Ford) vehicles the temperature gauge has been buffered, which is to say that it is a warning light masquerading as a gauge. Within a wide range of actual engine temperatures, it stays at exactly 12 o'clock. Just after starting it goes to the centre (straight up) position, and it doesn't move unless it has an extreme overheat, at which point it jumps to the far right. Interpolation is not possible.

Jeff

[Road Ruler]

Wondering what gear and RPM you were running at going up the climb?


Note.... For years we towed our 23' with a small V6 Nissan Mini Van. It was the GXE that came with a tow pkg. No problems.

Once a lady walked into our campground and asked if we towed the Airstream with the Quest. We said yes. She said they tried to tow a small pop-up with a Quest and it was always a struggle with power and overheating. The Nissan dealer found nothing wrong with the vehicle.

I suspect (an educated guess) her Quest had a problem (lurking in the background) that was affecting the performance when under load.

Perhaps your F150 has a similar quirk. ???

[xrvr]

What gear and rpm. Sometimes dropping down a gear can help. Jim

[Al and Missy]

To be honest, I'm not sure about the gear and rpm, but I think at the end I was doing around 30 MPH in first at around 2500-3000 rpm. I definitely was not lugging it at low RPM. I think the Edge Evolution tuner was doing a good job of matching the load. On this trip I saw something I have never seen when not towing. At times the transmission would lock the torque converter clutch while in third gear. Going up slight hills I would see it drop from 4th and locked to 4th and then to 3rd and locked and if a serious incline to 3rd and unlocked. I have never seen that in my flat road towing in Florida.

It has been suggested in a PM that I may have air bubbles in my cooling system or an improper mix of antifreeze and water. I'm going to look into those possibilities before my next tow.

On the way to Falluminum I'm going to look for a CAT scale and weigh the rig, but I think I'm within limits. I may be pushing truck payload, but not GCVWR.



Al

[Al and Missy]

I had a coolant flush and refill as a part of my 100K service 13K ago. I just looked at the coolant and based on what I read in my shop manual, there is very little coolant in the water. It is supposed to have a pronounced yellow/gold color and it looks mostly like water. I'm going to get an antifreeze tester to be sure but I have scheduled a flush and refill at the local dealer here in NC and I'll be having a discussion with the Service Manager of my local dealership when I get home. This is going to be a two strikes and you're out deal. They short filled my oil one time a year or so ago. Ever since I check the oil after I have a service.

I started having them do the service because oil changes on this truck are a pain because of the filter location. I guess I'll have to take it somewhere else in the future or buy the $180 filter relocation kit.

Al

[Nomad518]

You didn't say if the engine fan was running when you pulled over to open the hood and check the engine. I also have a 2001 Safari and I pull it with a 2012 F-150 5.0 V8. I haven't had any problems with overheating on this TV and I've towed over some pretty high passes here in California. However, on a previous TV I had overheating problems that turned out to be a failed clutch on the engine fan. As a result, the fan never clicked on to help cool the engine. The engine overheated and the radiator boiled over leaving me stranded on the side of a narrow winding mountain road until the engine cooled enough to drive on. You may also know that turning on the heater in your truck cabin helps to reduce the engine temperature in a pinch. On this particular trip, until I was able to get a repair made that's how I had to manage the overheating problem although it was very uncomfortable riding in the TV with the heater on, the windows down, and outside temperatures over 100 degrees. That's a trip I'd rather forget.

[Tuco]

Originally Posted by Al and Missy

It has been suggested in a PM that I may have air bubbles in my cooling system or an improper mix of antifreeze and water. I'm going to look into those possibilities before my next tow.

Your coolant system is designed to remove air as you thermally cycle the engine. As long as your coolant reservoir stays between the cold and hot marks, your coolant system will almost be air free after a few cycles. The antifreeze/water ratio is also not the problem. Water transfers heat almost 60% better that antifreeze (you stated in your next post that you thought there wasn't enough antifreeze in the coolant). I wasn't able to find any information on a 50/50 mix to see if the heat transfer coefficient becomes better than water at that ratio (but I doubt it). Things to look at are, a blown head gasket, stuck thermostat, bad fan clutch or cooling fan/temperature sensor or a plugged radiator/condenser. I am assuming Ford designed the cooling system with reserve capacity, but stranger things have happened.

[ggoat!!!]

Pure water is actually the most efficient coolant for your engine; it removes more heat than any coolant combination. The problem is that unless under pressure pure water provides no boil-over protection; that's why antifreeze/coolant is used. Not only for the anti-freeze properties in cold weather, but to also raise the boiling point (hence the "coolant" name). Concentrations of nearly pure antifreeze are not desired because while they raise the boiling point drastically, pure antifreeze is HORRIBLE at cooling the actual engine and while your engine may not boil over, it will run hot and gradually increase as you overload the thermal capacities of your cooling system.

Having not enough antifreeze in your coolant mixture definitely can cause your vehicle to overheat, especially once you hit the boiling point of your mixture under pressure. At that point, it's bubble city.

[Tuco]

I agree, so we need to add the radiator cap to the list of culprits. It looks like we gain 15 degrees to the boiling point with a 60/40 antifreeze/water mix @15psi. (250/265 degrees). With a bad radiator cap, corrosion or cavitation at the water pump may have damaged the impeller also, but after 13k miles that might be a stretch.

[Tyvekcat]

I know that pull up 421, from North Wilkesboro. Its not a walk in the park by any means. There are a bunch of similar pulls around and everyone of them will find a weak link in the cooling system. I am glad your truck was not harmed. My brother has the same setup in his F-150, 5.4 w/3.73. Its a good combo, but I keep telling him you cannot have that transmission fluid changed out to often. New fluid transmits heat better, in my opinion.

I just changed my Coolant, week before last. I need to go out and check and see if I need to add more.
That is a pretty area around Boone NC,
have a good one,

[Al and Missy]

Nomad, the fan was running, although I didn't make a judgement as to the speed. According to my shop manual, I have a viscous clutch and it should be turning at about 2/3 the engine RPM when hot. I wasn't expecting a problem, since the water temperature gauge was centerlined. The whole thing took me by surprise. The three temperatures I was measuring were all right at 230. I didn't know whether that was bad or good, but the water temperature gauge lulled me to sleep.

Tuco, thanks, my read of the manual said the same thing - no bleed screws.

Tuco and 75th Bambi, the shop manual does say that heat transfer will be degraded if there is not enough coolant in the mix. I understand what you are saying and I have read both, that coolant helps heat transfer and that pure water is better. The manual does say not to put in more than 50%. Looking at the overflow tank, I'd be surprised of there was more than a 10% mix.

I thought about the pressure cap (which is on the expansion/degassing tank) but there was no indication of any overflow or boiling looking at the tank. All the symptoms seem to point to heat not being transferred to the coolant. I think I'll have an overheating discussion with the dealership tomorrow when I take it in for a flush and fill. Maybe a defective water pump or thermostat?

Thanks for all the suggestions and comparisons. If I find a smoking gun I'll post the results.

Al

[Tuco]

Don't let them take you to the cleaners Al!

GL

[Al and Missy]

OK, got back from the dealer. If you ever need Ford service in the West Jefferson, NC area, check out Ashe County Ford. I went in and told them the whole story, including the thin looking coolant and asked them to check the mix first. They said the mix was good, protected down to -30. I asked them to check the thermostat and they said it was OK. They also said the pump flow was good. The service rep came into the waiting room, handed me my ticket and keys and said I was good to go. No charge. I asked if he was sure, and he said no charge. I gave them several opportunities to charge me for something and they said I didn't need it.

They opined that maybe 6000# was just too much for the truck on the 8 mile 6% grade. I asked about the temperature sensor staying centerlined and they didn't have an answer. Either the gauge on the dash or the sensor must be bad, in my opinion.

The Edge Evolution has alerts that can be set for most parameters it monitors. I checked and they were turned on. The default alert temperatures for cylinder head and engine oil were well above the 230 degrees I saw. I think the ATF temperature alert was set to 230 which is what I saw just as the problem occurred.

I guess I'll just have to watch everything the next time I tow. I realized today I have an infrared temperature gun. I'll keep it in the truck so I can check temperatures with it if it happens again.

Does anyone know if the gauge on the dash uses the same sensor as the PCM which the Edge monitors?

Thanks,

Al

[Tuco]

Glad you got away clean from the dealer. Just wondering if the truck is equipped with an automatic transmission cooler? Since you have a tuner on the truck this might be a situation where the next weakest link has been found. You may need a larger radiator and/or cooler for the engine and transmission. Hit up the ford forums and see what other modifications ppl with your truck/engine do after adding a tuner. I have been down this road many times before and you don't get something for nothing.

[Al and Missy]

Dave,

Thanks. The truck has the towing package with the largest transmission cooler that Ford provided that year. I've been digging and posting on the F150 forums today with no results yet. I think I won't know anything until I tow again and see what the tuner says the coolant temperature is. It's just weird that there was no indication of excessive heat or boilover under the hood.

Al

[J. Morgan]

I don't know, my 5.3 Chevy pulled an 8% grade south of Globe, AZ at about 35 no problem, while I don't have an add on tuner, the gauge never got close to hot in the Arizona summer. 6%, I can do at 70+.

230 isn't that hot for a modern engine.

If it is getting too hot for your taste on a grade take your foot out of the accelerator pedal till you top the crest.

Identical trucks can and do have different characteristics. Adapt to your particular vehicle and you can make it through.

[Tuco]

Al,

One other thing came to mind. When the PO modified my truck he installed a 4" exhaust to lower exhaust gas temps. Since adding the tuner also adds heat, a more free flowing exhaust might help with cooling. The Ford guys would know. A cheap fix would be to install a washer bottle from a junkyard and put the spray nozzle in front of the radiator. Since you only need extra cooling .001% of the time it might help and be inexpensive.