Airstream Forums

Airstream Forums (
-   Tow Vehicles (
-   -   2006 F150 5.4 Towing Difficulty (

Al and Missy 10-01-2014 06:33 PM

2006 F150 5.4 Towing Difficulty
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?



75TH BAMBI 10-01-2014 06:54 PM

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 10-01-2014 07:52 PM

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 10-02-2014 12:03 AM


Originally Posted by Al and Missy (Post 1518872)
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.


Road Ruler 10-02-2014 05:41 AM

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 10-02-2014 05:45 AM

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

Al and Missy 10-02-2014 09:07 AM

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 and Missy 10-02-2014 10:08 AM

Looks like a coolant problem
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.


Nomad518 10-02-2014 02:22 PM

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 10-02-2014 02:48 PM


Originally Posted by Al and Missy (Post 1519032)
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.

75TH BAMBI 10-02-2014 02:58 PM

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 10-02-2014 03:13 PM

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 10-02-2014 03:18 PM

Blue Ridge
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 10-02-2014 03:53 PM

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.


All times are GMT -6. The time now is 09:34 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.