More Cooling system trials

[rgorke]

I replaced my whole system last year (May 2018) with genuine Motorcraft parts. My '04 V8 with 247k miles is not overheating, however when sitting in LA traffic (ambient temp is upper 90s) the temp will rise to the mid 220s (227-228). When up to freeway speed the temp comes down to 210 ish and rolling down a hill I am under 200.

I recently noticed that there is the tell-tale signs of dried coolant around the base of the 9N499 neck pipe and when I took the spawn to school this morning, that dried coolant was damp. So, what to do? What to do? Not sure if the 9N499 is the culprit or whether it is seeping down from another location.

One issue is that I managed to "strip" the mounting nuts that hold the thermostat onto the 8549A Cross over pipe. By "strip" I mean the bolt turns the nut that is supposed to be solidly secured in the crossover pipe. I had epoxied them in but I am seeing that it didn't hold. I am thinking this may be the compromising issue that the thermostat housing isn't torqued properly.

Options?

1) confirm where the leak is seems to be of paramount importance but is usually difficult with these things. then...
2) re-epoxy nuts in crossover OR get longer bolts for the thermostat mounting and use a nut on the back end of the crossover to torque properly.
3) Replace both parts (9N499 and crossover) ...but with only 18 months that hurts but isn't too expensive. However, if one or both have a micro crack due to the 10 thumbed mechanic, this may be the wise choice.

Thoughts? Again, not "technically" overheating but not functioning at 100%.

 

[joegr]

I'd replace those parts (I'd go with a new thermostat and front housing too), and all the involved seals. Check the front of the heads where the crossover seals to them very carefully too. Any residue on the metal where the seals contact can cause problems.

 

[rgorke]

I'd replace those parts (I'd go with a new thermostat and front housing too), and all the involved seals. Check the front of the heads where the crossover seals to them very carefully too. Any residue on the metal where the seals contact can cause problems.

Yep, just looked after the school pickup and saw some coolant stains between the thermostat housing and crossover...I (probably foolishly) grabbed my SO Torquometer and when I got to 80 in/lbs, the bolt moved and then I had a nice little squirt coming out from between the housings...UGH!!!!

 

[04_Sport_LS]

The upper o-ring on the 9N499 gooseneck is a typical leak point. The trick is to lubricate it with a little coolant when installing the 8548A crossover pipe. The coolant helps seat the gooseneck pipe deeper in the crossover pipe during install.

I actually mate the 2 pieces together first... and install them as one piece.

 

[04_Sport_LS]

Always torque cooling system parts when cold... especially plastic.

Course you probably figured that out by now.

 

[rgorke]

Thanks for the tips. I think I FINALLY have the whole system working 100%! The real test will be sitting in traffic on a hot day but currently running low 190s on the freeway.

I actually did the coolant trick installing the crossover pipe into the 9N499. Pics below of the pieces I took off. The O ring around the 9N499 looks really smashed. You can see the stuck bolt and where the coolant had sprayed. I honestly don’t think there are cracks or anything in the pieces themselves, the leaks are coming from the mating points and not being able to torque the bolts properly and/or the gaskets not sealing properly. Regardless, all new parts installed.

And, the ancillary issues...the hardest part is having to take the intake manifold off. I had, unnecessarily, unplugged the sensors under the IM. Then, putting the IM back on, I had one of them, the crankcase temp sensor I believe, routed wrong so They don’t lay right behind the fuel injectors. Just dumb stuff like that!!!

 

[04_Sport_LS]

The O ring around the 9N499 looks really smashed

That's why you try to get it seated as deep as possible. It helps with longevity.

Hard to believe those Motorcraft parts only lasted a year and a half. They look pretty ugly.

 

[rgorke]

Update:

I am not sure what is going on or whether this is the way the system works but when I am driving "normal" freeway speeds 55-80 mph, the "coolant temp" as displayed through my OBDII interface is 190-200, maybe 205. Once I stop and sit in traffic for an extended time period (10-15 mins) with the AC on, the temp will rise up to 225. This is even when the outside temp is below 70 degrees. Once it gets to this level, I have turned the heater on and the temp drops back down to 210-212. When I get rolling again, the temp is back in the high 190s, low 200s, even with the AC not heater on.

The thermostat, T-stat housing, crossover pipe, 9N499 neck pipe, gaskets, degas bottle are all new. Water pump is 1 year old, Radiator and DCCV valve are 3 years old. Radiator Hoses are under 4 years old.

What could be causing this? Once hot over the last few days, I have opened the bleeder valve and gotten a few splats of air before just coolant. Do I need more bleeding? Radiator flush?

I see no visible splatters of coolant markings showing something might be leaking.

I am at a loss...Thanks

 

[04_Sport_LS]

Could still have a touch of air in it.

Running warmer sitting at idle is normal... compared to cruising down the highway where you have more airflow.

The AC puts an extra load on the engine, causing it to run warmer.

However... at the same time, turning on the AC should cause the fan to spin up.

Could try taking it for a quick spin around the block, (with the A/C on) ... to get it up to temp. and monitor fan speed.

Could be your fan wants to take a vacation.

 

[rgorke]

I also noticed that the 06 manual on line says "Start the engine and turn the heater to the defrost (90°F) position." My 04 manual omits "defrost". I am curious as to the difference, if any?

 

[04_Sport_LS]

If I had to speculate... maybe it forces the DCCV to open all the way... whereas the rest of the settings are "modulated"?

 

[AmsterDutch]

I also noticed that the 06 manual on line says "Start the engine and turn the heater to the defrost (90°F) position." My 04 manual omits "defrost". I am curious as to the difference, if any?

This is pretty petty but I have always used the defrost setting to 90 °F...I have no proof that this helps it bleed better but my 02' LSE is running 198-200 in town and 195 on Highway as 04' knows my degas was literally bubbling before I changed out my degas reservoir ...I also took heed to the advise of a former Mechanic and LS owner on the forum and did laps around the block with degas reservoir cap loose while doing bleeding procedures to a (T)
I then left the car sit for a week and when I took it out I never had a car run cooler