Another Radiator / Cooling System / Thermostat + (Housing) / Rough Idle / No Heat ...

[IAR]

So here goes for anyone who is just stumbling their way into something similar,

Sept 2014 - after a DIY tune-up (plugs, wires, oil, filters) to resolve a suddenly slight rough acceleration (approx. 40-50MPH only) the truck was running the best it ever had, save for not correcting the slight rough acceleration! Anyhow after reading through many of these threads, ordered a new EGR to hopefully save the day.

Meanwhile I was cruising the freeway in the early September sun with the moonroof open enjoying the ride and then bam! Billowing white smoke flying from under the hood and engine lights and flashing red CELs - like an airplane ****pit under duress. I'm at the top of the skyway at highway speed so nowhere to safely pull over so I drop into neutral to control steering and coast 2 miles down the other side of the bridge and there's no exit in sight... perfect! When I rolled to a stop I shut it off, sat for 5 minutes and popped the hood, coolant everywhere! About 20,000 miles previously I had replaced the factory radiator, as we all know it has its issues, so I looked it over good expecting the coolant to be pissing out, no dice. It was hard to see for all the steam so I let it sit another 10 minutes, added the small bottle of coolant I had directly to the rad and started it up to slow idle off the freeway to the gas station at the closest exit. (<1 mile)

Local garage fixed the thermostat housing which had cracked, and the thermostat
and got it back together 5 hrs. later.

The way home the truck ran real rough. Gone was the great tune-up feel from that afternoon, but at least I was able to get home.

Finally had to bite the bullet and take to Ford dealership after no heat at idle (but otherwise cabin heat was great), and the news was not good - head gasket repair!

$1500 later not including the $300 emergency thermostat housing repair, the truck was running but the no heat at anything below 2K RPM was still there.

Also there was still a small misfire in No.1 cylinder, enough to trigger the CEL here and there. Tech said maybe 1 miss in every 100K or so. Not what I wanted to hear after shelling out fifteen hundo, but hey it's just $$ right? I live in the snow belt so with a newborn so no heat wasn't going to fly. Couldn't pre-heat the car in the driveway, no defrost - at least the heated seats would work.

Back to Ford, they said the emergency thermostat housing fix had been done with silicone and then Bars Leak added which after 6 more cooling system flushings still was pushing out residue which they believe was blocking heat at low RPMs. Heater line was hot hot coming out but ice cold heading into the cabin.

Heater core fix is $800, used 62,000 mile motor is $4200 installed at Ford.

I have done neither, the truck is a 2006 4.0L EB with 120,000 miles, not sure of that ROI. Sucked it up and drove fast to hit 2,000 RPM for heat - hard to do in the city, and bought a Cadillac for the wife and baby.

Truck is leaking coolant again at a rate of 1/2 jug per week. Rad is still good but the thermostat housing made of fine Chinese plastic is a leaky sieve. Nice to see they only sell more plastic replacements, I know there is a metal solution but it's in Tennessee and I'm not - so tomorrow I'll fix with another piece of plastic....

I still like my Ford but the cooling system is really, really, really more than a joke.

 

[MotorCityFats13]

the main problem with the t-stat housing is the bond between the seams.... the one side that bolts to the engine is pinched between the top and bottom with the bolts but on the goose neck side the bolts only hold the neck to the middle and the middle to the bottom is just glue... so easy fix is to get longer bolts and drill out the threads on the cage nuts and use nuts so all 3 pieces are pinched tight.... the bonding failures are eliminated with this fix so the thing has to crack to leak and that is not the weak link to this pos contraption... you can get replacements online for under $20 and the swap is really a 20 minute job if you take a few beer breaks every 3 minutes...

 

[IAR]

Thanks for the insight, I did shore up the seams similar to your description, the old housing wasn't even broken - the front two bolts on top of the gooseneck going to the radiator were overtightened originally (I think spec is 8ft. lbs?) This caused the embedded nut to to pry the seam open, which I believe was compounded by heat warping or melting it over time (Ha! 6 months) causing the coolant to spew out the rear of the top connection.

I installed the new one anyway. Secondly I followed this video -
https://www.youtube.com/watch?v=baAAYM5Cl00

but used CLR to sit in the heater core for 1.5 hours, then flushed 2-3 times with water. Still no heat at idle but significant increase in heat (40% hotter) when driving and now heat at 1000 RPM vs. before needing to hit 2000 RPM. Will make a difference for my city driving.

I might try this again to see if heat flow improves.

 

[MotorCityFats13]

my heat is shaky at best.. the worst part is the horrible design of the floor vents... really a 1 inch pipe is going to heat both my feet... sometimes my heat is decent and other times its blows warm under 2,000 rpm... any colder than 15F all bets are off and it acts really weird.... I like heat that melts your hand so you have to turn it down... but my 2007 4.0 never gets like that unless its like 35f or warmer outside.... reading the obdII it reads 192F when it warms up but the heat feels like it never get over 75F.... my 1999 f-150 5.4L used to read over 150F at the vents as did my 1998 4.0 xlt.... this 4th gen is not making me happy and I have not even had is for 2 months

 

[IAR]

Update on Core

So after 1st flush used Liquid Plumber to sit in core for 2 hours. Flush again with water each way with water 4 times. Sediment came out still after total now 12 or so flushes. The heat improved another 30% conservatively, for a total of 70% at minimum.

AC now works great as well.

 

[Flag Gibby]

Sorry to hear of all the issues. On this generation of vehicles the worst thing that you can do to the cooling system is use some sort of stop leak on it because it completely plugs up the very small cooling passages and the heater cores on these vehicles (as you have definitely experienced). The most common thing that I see happen when the radiators get replaced is individuals reuse the same radiator cap instead of a brand new one and I would like to think that a good portion of thermostat housing failures is due to a faulty radiator cap causing the system pressure to be too high especially when the most common fix on our generation (to avoid housing/radiator cracks) is to go with a lower pressure cap.